MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Beilstein Journal of Organic Chemistry' source. Thu, 09 Feb 2012 13:01:27 +0100 http://www.medworm.com/index.php?rid=5673486&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-24.pdf Abstract A series of di-, tri- and tetravalent axles and wheels for the synthesis of pseudorotaxanes bearing the tetralactam macrocycle/diamide axle binding motif was prepared. Starting from iodinated monovalent precursors, Sonogashira cross-coupling reactions were utilized to couple the binding sites to appropriate spacer groups. Through this “Lego” or “toolbox” approach, the convergent synthesis of host and guests with a well-defined number of the binding sites is possible. In addition, the spatial arrangement of the binding sites can be controlled through the quite rigid connections between linker and binding sites. Although a quantitative assessment of binding strengths was not possible by NMR titration experiments, typical and significant shifts of the signals ... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5673486 Thu, 09 Feb 2012 05:00:00 +0100 5673486 http://www.medworm.com/index.php?rid=5673487&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-23.pdf Abstract A clean process has been developed for the synthesis of 2-adamantylphenol derivatives through adamantylation of substituted phenols with adamantanols catalyzed by commercially available and recyclable ion-exchange sulfonic acid resin in acetic acid. The sole byproduct of the adamantylation reaction, namely water, could be converted into the solvent acetic acid by addition of a slight excess of acetic anhydride during the work-up procedure, making the process waste-free except for regeneration of the ion-exchange resin, and facilitating the recycling of the resin catalyst. The ion-exchange sulfonic acid resin catalyst could be readily recycled by filtration and directly reused at least ten times without a significant loss of activity. The key intermediate of adapalene, 2-(1-adamant... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5673487 Wed, 08 Feb 2012 11:45:00 +0100 5673487 http://www.medworm.com/index.php?rid=5673488&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-22.pdf Abstract Hexahomotrioxacalix[3]arenes, commonly called oxacalix[3]arenes, were first reported in 1962. Since then, their chemistry has been expanded to include numerous derivatives and complexes. This review describes the syntheses of the parent compounds, their derivatives, and their complexation behaviour towards cations. Extraction data are presented, as are crystal structures of the macrocycles and their complexes with guest species. Applications in fields as diverse as ion selective electrode modifiers, fluorescence sensors, fullerene separations and biomimetic chemistry are described. Beilstein J. Org. Chem. 2012, 8, 201–226. doi:10.3762/bjoc.8.22 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5673488 Tue, 07 Feb 2012 14:01:00 +0100 5673488 http://www.medworm.com/index.php?rid=5663897&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-21.pdf Abstract A concise synthesis of 3-(1-alkenyl)isoindolin-1-ones and 5-(1-alkenyl)pyrrol-2-ones has been achieved by the coupling reactions of N-acyliminium ions produced from 3-hydroxyisoindol-1-ones or 5-hydroxy-1-pyrrol-2-ones with unactivated olefins in the presence of BF3·OEt2 at room temperature. For most of the olefins, the reactions afforded the Csp3–Csp2 cross-coupling products, but for the α-methylstyrene and 1-hexene, the Csp3–Csp3 cross-coupling products were obtained. Beilstein J. Org. Chem. 2012, 8, 192–200. doi:10.3762/bjoc.8.21 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5663897 Mon, 06 Feb 2012 05:00:00 +0100 5663897 http://www.medworm.com/index.php?rid=5655909&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-20.pdf Abstract The hydroxylation of n-alkanes, which proceeds in the presence of a P450-monooxygenase advantageously at temperatures significantly below room temperature, is described. In addition, an enzymatic hydroxylation of the “liquid gas” n-butane with in situ cofactor regeneration, which does not require high-pressure conditions, was developed. The resulting 2-butanol was obtained as the only regioisomer, at a product concentration of 0.16 g/L. Beilstein J. Org. Chem. 2012, 8, 186–191. doi:10.3762/bjoc.8.20 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5655909 Fri, 03 Feb 2012 05:00:00 +0100 5655909 http://www.medworm.com/index.php?rid=5655910&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-19.pdf Abstract A simple, efficient and highly diastereoselective one-pot three-component synthesis of functionalized 2,6-disubstituted-4-tosyloxytetrahydropyrans was performed. The synthesis features an optimized Prins cyclization in which an aromatic homoallylic alcohol, an aromatic/aliphatic aldehyde, and p-toluenesulfonic acid (catalyst and reagent) are reacted in the presence of molecular sieves (MS) 4 Å at reflux in dichloromethane to afford excellent yields (72–96%) within short reaction times (20–90 min). The MS 4 Å-promoted synthesis proved to be versatile enough to provide an array of symmetrical and unsymmetrical tetrahydropyran derivatives in economical manner. Furthermore, cleavage of the 4-tosyl group under mild conditions afforded 4-hydroxytetrahydropyran in e... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5655910 Wed, 01 Feb 2012 09:34:00 +0100 5655910 http://www.medworm.com/index.php?rid=5643469&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-18.pdf Abstract Five carbamate derivatives, obtucarbamates C and D (1, 2), dimethyl ((carbonylbis(azanediyl))bis(2-methyl-5,1-phenylene))dicarbamate (3), obtucarbamates A and B (4, 5), and four aromadendrane-type sesquiterpenoids, (+)-4β-N-methenetauryl-10β-methoxy-1β,5α,6β,7β-aromadendrane (6), (−)-4β-N-methenetauryl-10β-methoxy-1β,5β,6α,7α-aromadendrane (7), (−)-4α,10β-aromadendranediol (8), (+)-4β,10β-aromadendranediol (9) were obtained from the South China Sea gorgonian coral Melitodes squamata Nutting. Compounds 1, 2, 6, and 7 were new, and their structures were established by spectroscopic analyses. Compounds 6 and 7 contained a taurine group that was rarely found in marine natural compounds, and 7 s... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5643469 Tue, 31 Jan 2012 05:00:00 +0100 5643469 http://www.medworm.com/index.php?rid=5643470&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-17.pdf Abstract A new, straightforward and high yielding procedure to convert oleanolic acid derivatives into the corresponding δ-hydroxy-γ-lactones, by using the convenient oxidizing agent magnesium bis(monoperoxyphthalate) hexahydrate (MMPP) in refluxing acetonitrile, is reported. In addition, a two-step procedure for the preparation of oleanolic 12-oxo-28-carboxylic acid derivatives directly from Δ12-oleananes, without the need for an intermediary work-up, and keeping the same reaction solvent in both steps, is described as applied to the synthesis of 3,12-dioxoolean-28-oic acid. Beilstein J. Org. Chem. 2012, 8, 164–169. doi:10.3762/bjoc.8.17 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5643470 Mon, 30 Jan 2012 09:06:00 +0100 5643470 http://www.medworm.com/index.php?rid=5624339&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-15.pdf Abstract Bent-core mesogens have gained considerable importance due to their ability to form new mesophases with unusual properties. Relationships between the chemical structure of bent-core molecules and the type and physical properties of the formed mesophases are relatively unknown in detail and differ strongly from those known for calamitic liquid crystals. In this paper symmetric and nonsymmetric five-ring salicylideneaniline-based bent-core mesogens are presented, and the effect of lateral substituents attached at the outer phenyl rings (F, Cl, Br) or the central phenyl ring (CH3) on the liquid-crystalline behaviour and on the physical properties is studied. Corresponding benzylideneaniline-based compounds were additionally prepared in order to study the influence of the intramolecul... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5624339 Tue, 24 Jan 2012 11:22:00 +0100 5624339 http://www.medworm.com/index.php?rid=5624340&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-14.pdf Abstract It has been shown that the base-initiated cyclo-oligomerisation of phthalonitriles is favoured by bulky α-substituents making it possible to obtain the metal-free phthalocyanine directly and in high yield. The phthalocyanine with eight α-isoheptyl substituents gives a high time-of-flight hole mobility of 0.14 cm2·V−1·s−1 within the temperature range of the columnar hexagonal phase, that is 169–189 °C. Beilstein J. Org. Chem. 2012, 8, 120–128. doi:10.3762/bjoc.8.14 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5624340 Tue, 24 Jan 2012 11:19:00 +0100 5624340 http://www.medworm.com/index.php?rid=5624341&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-13.pdf Beilstein J. Org. Chem. 2012, 8, 118–119. doi:10.3762/bjoc.8.13 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5624341 Tue, 24 Jan 2012 11:15:00 +0100 5624341 http://www.medworm.com/index.php?rid=5624338&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-16.pdf Abstract The chirality transfer in liquid crystals induced by two helical perylenequinones (namely, the natural compounds cercosporin and phleichrome) was investigated by integrating measurements of helical twisting power with a conformational analysis by DFT calculations and with the prediction of their twisting ability by the surface-chirality method. The two quasi-enantiomeric derivatives induce oppositely handed cholesteric phases when introduced as dopants in nematic solvents. We evaluated the role of the different conformations of the chiral hydroxyalkyl side chains in determining the helical twisting power: They were found to affect the strength of the chirality transfer, although the handedness of the induced cholesteric phase is essentially determined by the axial chirality (helic... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5624338 Tue, 24 Jan 2012 05:00:00 +0100 5624338 http://www.medworm.com/index.php?rid=5616595&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-12.pdf Abstract The conformational isomerism and stereoelectronic interactions present in 2'-haloflavonols were computationally analyzed. On the basis of the quantum theory of atoms in molecules (QTAIM) and natural bond orbital (NBO) analysis, the conformer stabilities of 2'-haloflavonols were found to be dictated mainly by a C=O···H–O intramolecular hydrogen bond, but an unusual C–F···H–O hydrogen-bond and intramolecular C–X···O nonbonding interactions are also present in such compounds. Beilstein J. Org. Chem. 2012, 8, 112–117. doi:10.3762/bjoc.8.12 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5616595 Sat, 21 Jan 2012 05:00:00 +0100 5616595 http://www.medworm.com/index.php?rid=5603485&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-11.pdf Abstract Heating aldehydes that contain a protected hydroxymethyl group, a tethered alkyl chloride and a tethered alkenyl group at the α-position of the aldehyde with an amine sets up a cascade (tandem) reaction sequence involving condensation to an intermediate imine, then cyclization and formation of an intermediate azomethine ylide and then intramolecular dipolar cycloaddition. The fused tricyclic products are formed with complete or very high stereochemical control. The hydroxymethyl group was converted into an aldehyde – which could be removed to give the tricyclic amine products that are unsubstituted at the ring junction positions – or was converted into an alkene, which allowed the formation of the core ring system of the alkaloids scandine and meloscine. Beilstei... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5603485 Wed, 18 Jan 2012 05:00:00 +0100 5603485 http://www.medworm.com/index.php?rid=5603486&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-10.pdf Abstract A rapid and simple procedure was devised for the synthesis of multifunctionalized cyclic β-amino esters and γ-amino alcohols via the 1,3-dipolar cycloaddition of nitrile oxides to β-aminocyclopentenecarboxylates. The opening of the isoxazoline reductive ring to the corresponding highly functionalized 2-aminocyclopentanecarboxylates occurred stereoselectively with good yields. Beilstein J. Org. Chem. 2012, 8, 100–106. doi:10.3762/bjoc.8.10 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5603486 Tue, 17 Jan 2012 11:27:00 +0100 5603486 http://www.medworm.com/index.php?rid=5603487&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-9.pdf Abstract We used dynamic 1H NMR spectroscopic methods to examine the kinetics and thermodynamics of CH3CCl3 (2) entering and leaving the gated molecular basket 1. We found that the encapsulation is first-order in basket 1 and guest 2, while the decomplexation is zeroth-order in the guest. Importantly, the interchange mechanism in which a molecule of CH3CCl3 directly displaces the entrapped CH3CCl3 was not observed. Furthermore, the examination of the additivity of free energies characterizing the encapsulation process led to us to deduce that the revolving motion of the gates and in/out trafficking of guests is synchronized, yet still a function of the affinity of the guest for occupying the basket: Specifically, the greater the affinity of the guest for occupying the basket, the less effe... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5603487 Mon, 16 Jan 2012 12:49:00 +0100 5603487 http://www.medworm.com/index.php?rid=5592225&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-8.pdf Abstract For the condensation of anions such as phosphate and ADP to form ATP and water, nature employs sophisticated supramolecular systems to overcome coulomb repulsion and activation barriers. For an attempt to create a simple, analogous chemical system, the dimerization of vanadate is probably the simplest model. We have investigated Zn-benzylcyclene which favors the dimerization thermodynamically as shown by NMR titration. Moreover, EXSY NMR experiments reveal that the vanadate dimer is also kinetically stabilized with respect to hydrolysis by complexation with Zn-cyclene. Beilstein J. Org. Chem. 2012, 8, 81–89. doi:10.3762/bjoc.8.8 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5592225 Sun, 15 Jan 2012 05:00:00 +0100 5592225 http://www.medworm.com/index.php?rid=5592226&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-7.pdf Abstract The syntheses of three new [3]radialenes – hexakis(3,5-dimethylpyrazolyl)-, hexakis(3-cyanophenyl)-, and hexakis(3,4-dicyanophenyl)[3]radialene (1–3) – are reported. Compound 3 is obtained in five steps with an excellent yield of 76% in the key step. Compared to that, the respective steps of the syntheses of 1 and 2 result in lower yields. All compounds adopt a double bladed propeller conformation in solution. Compound 3 is considerably more electron deficient than previously reported hexaaryl[3]radialenes, with reduction potentials of −0.06 and −0.45 V in CH2Cl2. The compounds mostly display red fluorescence with large Stokes shifts. Beilstein J. Org. Chem. 2012, 8, 71–80. doi:10.3762/bjoc.8.7 (Source: Beilstein Journal of Organic Chemist... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5592226 Wed, 11 Jan 2012 11:24:00 +0100 5592226 http://www.medworm.com/index.php?rid=5592227&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-6.pdf Abstract A general and facile one-pot protocol for the preparation of a broad range of alkyl and aryl isothiocyanates has been developed from their corresponding primary amines under aqueous conditions. This synthetic process involves an in situ generation of a dithiocarbamate salt from the amine substrate by reacting with CS2 followed by elimination to form the isothiocyanate product with cyanuric acid as the desulfurylation reagent. The choice of solvent is of decisive importance for the successful formation of the dithiocarbamate salt particularly for highly electron-deficient substrates. This novel and economical method is suitable for scale-up activities. Beilstein J. Org. Chem. 2012, 8, 61–70. doi:10.3762/bjoc.8.6 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5592227 Tue, 10 Jan 2012 10:29:00 +0100 5592227 http://www.medworm.com/index.php?rid=5576329&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-5.pdf Abstract N,N-Diisopropyl-2-propylbenzamide 6-H undergoes lateral deprotonation by t-BuLi in the presence of the Lewis base PMDTA (N,N,N′,N″,N″-pentamethyldiethylenetriamine) to give a benzyllithium 6-Lil·PMDTA that incorporates a trigonal planar secondary carbanion. In the solid state, the amide directing group and the PMDTA additive work together to abstract the metal ion from the deprotonated α-C of the propyl group (4.107(4) Å). A short distance of 1.376(3) Å is observed between the deprotonated carbon centre and a planar aromatic system that shows a pattern of bond lengths which contrasts with that reported for related tertiary carbanion systems. Analogous benzylic deprotonation is seen if 6-H is treated with t-BuLi in the presence of diglyme to gi... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5576329 Mon, 09 Jan 2012 05:00:00 +0100 5576329 http://www.medworm.com/index.php?rid=5568250&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-4.pdf Abstract Research activities in the field of imidazole-derived push–pull systems featuring intramolecular charge transfer (ICT) are reviewed. Design, synthetic pathways, linear and nonlinear optical properties, electrochemistry, structure–property relationships, and the prospective application of such D-π-A organic materials are described. This review focuses on Y-shaped imidazoles, bi- and diimidazoles, benzimidazoles, bis(benzimidazoles), imidazole-4,5-dicarbonitriles, and imidazole-derived chromophores chemically bound to a polymer chain. Beilstein J. Org. Chem. 2012, 8, 25–49. doi:10.3762/bjoc.8.4 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5568250 Sat, 07 Jan 2012 00:12:06 +0100 5568250 http://www.medworm.com/index.php?rid=5568251&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-3.pdf Abstract The multicomponent reaction of 5-aminopyrazole derivatives with cyclic 1,3-dicarbonyl compounds and dimethylformamide dimethylacetal (DMFDMA) in DMF at 150 °C under controlled microwave heating afforded regioselectively 8,9-dihydropyrazolo[1,5-a]quinazolin-6(7H)-ones 6 rather than the corresponding dihydropyrazolo[5,1-b]quinazolin-8(5H)-ones 4. Beilstein J. Org. Chem. 2012, 8, 18–24. doi:10.3762/bjoc.8.3 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5568251 Wed, 04 Jan 2012 13:31:00 +0100 5568251 http://www.medworm.com/index.php?rid=5568252&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-2.pdf Abstract A bi-macrocycle with an incorporated isophthalamide substructure was synthesized by double amide formation between an isophthaloyl dichloride and two equivalents of a bis(alkenyloxy)aniline, followed by ring-closing metathesis and hydrogenation. In contrast to many related isophthalamides, the concave host exhibits a better binding for oxides, such as DMSO or pyridine-N-oxide, than for halide anions. A general method for a quick estimation of the strength of binding derived from only a few data points is presented and gives an estimated Kass of pyridine-N-oxide of ca. 40 M−1, NMR titration confirms 25 M−1. Beilstein J. Org. Chem. 2012, 8, 11–17. doi:10.3762/bjoc.8.2 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5568252 Tue, 03 Jan 2012 13:19:00 +0100 5568252 http://www.medworm.com/index.php?rid=5568253&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-8-1.pdf Abstract 1,3,5-triethylbenzenes have been widely used as supramolecular templates to organize molecular-recognition elements. It is believed that the steric-gearing effect of the 1,3,5-triethylbenzene template directs the binding elements toward the same face of the central ring, hence increasing the binding affinity. At the same time the 1,3,5-trimethylbenzene scaffold, without steric-gearing effects, has also been found to improve the binding affinities of hosts compared to the unsubstituted analogues. By studying experimental data from the literature and the Cambridge Structural Database, as well as by conducting computational studies of representative structures, we concluded that the steric gearing offered by the ethyl groups confers some energetic advantage over the methyl groups, bu... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5568253 Mon, 02 Jan 2012 10:22:00 +0100 5568253 http://www.medworm.com/index.php?rid=5556580&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-205.pdf Abstract A variety of 2-amino-3-arylpropan-1-ols, anti-2-amino-3-aryl-3-methoxypropan-1-ols and anti-2-amino-1-arylpropan-1,3-diols were prepared selectively through elaboration of trans-4-aryl-3-chloro-β-lactams. In addition, a number of 2-(azidomethyl)aziridines was converted into novel 2-[(1,2,3-triazol-1-yl)methyl]aziridines by Cu(I)-catalyzed azide-alkyne cycloaddition, followed by microwave-assisted, regioselective ring opening by dialkylamine towards 1-(2,3-diaminopropyl)-1,2,3-triazoles. Although most of these compounds exhibited weak antiplasmodial activity, six representatives showed moderate antiplasmodial activity against both a chloroquine-sensitive and a chloroquine-resistant strain of Plasmodium falciparum with IC50-values of ≤25 μM. Beilstein J. Org. Chem. ... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5556580 Sun, 01 Jan 2012 05:00:00 +0100 5556580 http://www.medworm.com/index.php?rid=5549331&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-204.pdf Abstract The synthesis of multifunctional indenes with at least two different functional groups has not yet been extensively explored. Among the plausible synthetic routes to 3,5-disubstituted indenes bearing two different functional groups, such as the [3-(aminoethyl)inden-5-yl)]amines, a reasonable pathway involves the (5-nitro-3-indenyl)acetamides as key intermediates. Although several multistep synthetic approaches can be applied to obtain these advanced intermediates, we describe herein their preparation by an aldol-type reaction between 5-nitroindan-1-ones and the lithium salt of N,N-disubstituted acetamides, followed immediately by dehydration with acid. This classical condensation process, which is neither simple nor trivial despite its apparent directness, permits an efficient ent... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5549331 Thu, 29 Dec 2011 05:00:00 +0100 5549331 http://www.medworm.com/index.php?rid=5549332&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-203.pdf Abstract The protonation equilibria of four substituted N-methylbenzenesulfonamides, X-MBS: X = 4-MeO (3a), 4-Me (3b), 4-Cl (3c) and 4-NO2 (3d), in aqueous sulfuric acid were studied at 25 °C by UV–vis spectroscopy. As expected, the values for the acidity constants are highly dependent on the electron-donor character of the substituent (the pKBH+ values are −3.5 ± 0.2, −4.2 ± 0.2, −5.2 ± 0.3 and −6.0 ± 0.3 for 3a, 3b, 3c and 3d, respectively). The solvation parameter m* is always higher than 0.5 and points to a decrease in the importance of solvation on the cation stabilization as the electron-donor character of the substituent increases. Hammett plots of the equilibrium constants showed a better correlation with the σ+ substituen... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5549332 Tue, 27 Dec 2011 10:23:00 +0100 5549332 http://www.medworm.com/index.php?rid=5532612&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-202.pdf Abstract Sexithiophenes 1a and 1b, in which a 4-(dimethylamino)phenyl unit is incorporated as an end-capping group, were synthesised and characterised by cyclic voltammetry, absorption spectroscopy and UV–vis spectroelectrochemistry. Additionally, their ability to function as effective luminescence quenchers for quantum dot emission was studied by photoluminescence spectroscopy and compared with the performance of alkyl end-capped sexithiophenes 2a and 2b. Beilstein J. Org. Chem. 2011, 7, 1722–1731. doi:10.3762/bjoc.7.202 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5532612 Fri, 23 Dec 2011 05:00:00 +0100 5532612 http://www.medworm.com/index.php?rid=5532613&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-201.pdf Abstract The valence isomerization of the all-carbon and heteroelement analogues of cyclohepta-1,3,5-triene into the corresponding bicyclo[4.1.0]hepta-2,4-dienes is reviewed to show the impact of the heteroatom on the stability of both valence isomers. The focus is on the parent systems and their synthetic applications. Beilstein J. Org. Chem. 2011, 7, 1713–1721. doi:10.3762/bjoc.7.201 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5532613 Wed, 21 Dec 2011 13:00:00 +0100 5532613 http://www.medworm.com/index.php?rid=5532614&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-200.pdf Abstract The volatiles released by Micromonospora aurantiaca were collected by means of a closed-loop stripping apparatus (CLSA) and analysed by GC–MS. The headspace extracts contained more than 90 compounds from different classes. Fatty acid methyl esters (FAMEs) comprised the major compound class including saturated unbranched, monomethyl and dimethyl branched FAMEs in diverse structural variants: Unbranched, α-branched, γ-branched, (ω−1)-branched, (ω−2)-branched, α- and (ω−1)-branched, γ- and (ω−1)-branched, γ- and (ω−2)-branched, and γ- and (ω−3)-branched FAMEs. FAMEs of the last three types have not been described from natural sources before. The structures for all FAMEs have been sug... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5532614 Tue, 20 Dec 2011 13:31:00 +0100 5532614 http://www.medworm.com/index.php?rid=5520129&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-199.pdf Abstract A series of 6,8-diiodocoumarin-3-N-carboxamides (4–11) were prepared. Treatment of ethyl 6,8-diiodocoumarin-3-carboxylate (1) with ethyl cyanoacetate/NH4OAc gave ethyl 2-(3-carbamoyl-6,8-diiodocoumarin-4-yl)-2-cyanoacetate (12) and 2-amino-4-hydroxy-7,9-diiodocoumarino[3,4-c]pyridine-1-carbonitrile (13), and treatment with acetone in the presence of NH4OAc or methylamine gave the ethyl 4-oxo-2,6-methano-2-methyl-3,4,5,6-tetrahydro-8,10-diiodobenzo[2,1-g]-2H-1,3-oxazocine-5-carboxylate derivatives 14a,b. All compounds were evaluated for their antimicrobial activity and the compounds 12–14a,b exhibited a pronounced effect on all tested microorganisms. Beilstein J. Org. Chem. 2011, 7, 1688–1696. doi:10.3762/bjoc.7.199 (Source: Beilstein Journal of Organic Chem... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5520129 Tue, 20 Dec 2011 05:00:00 +0100 5520129 http://www.medworm.com/index.php?rid=5511784&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-198.pdf Abstract A simple, practical and efficient continuous-flow hydration–condensation protocol was developed for the synthesis of α,β-unsaturated ketones starting from alkynes and aldehydes by employing a heterogeneous catalyst in a flow microwave. The procedure presents a straightforward and convenient access to valuable differently substituted chalcones and can be applied on multigram scale. Beilstein J. Org. Chem. 2011, 7, 1680–1687. doi:10.3762/bjoc.7.198 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5511784 Sat, 17 Dec 2011 05:00:00 +0100 5511784 http://www.medworm.com/index.php?rid=5511785&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-197.pdf Abstract Herein, we demonstrate that a homogeneous catalyst can be prepared continuously via reaction with a packed-bed of a catalyst precursor. Specifically, we perform continuous proline catalyzed α-aminoxylations using a packed-bed of L-proline. The system relies on a multistep sequence in which an aldehyde and thiourea additive are passed through a column of solid proline, presumably forming a soluble oxazolidinone intermediate. This transports a catalytic amount of proline from the packed-bed into the reactor coil for subsequent combination with a solution of nitrosobenzene, affording the desired optically active α-aminooxy alcohol after reduction. To our knowledge, this is the first example in which a homogeneous catalyst is produced continuously using a packed-bed. We pred... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5511785 Wed, 14 Dec 2011 10:25:00 +0100 5511785 http://www.medworm.com/index.php?rid=5500642&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-196.pdf Abstract New trans- and cis-o-stilbene-methylene-sydnones 3a,b were synthesized by transforming the trans- and cis-o-aminomethylstilbene derivative, obtained by reduction of corresponding o-cyano derivatives, into glycine ester derivatives (43 and 31% yield) followed by hydrolysis (90 and 96% yield), nitrosation and ring closure with acetic acid anhydride (30 and 40% yield). The products were submitted to photochemical and thermal intramolecular [3 + 2] cycloadditions to afford diverse heteropolycyclic compounds. Photochemical reactions afforded cis-3-(4-methylphenyl)-3a,8-dihydro-3H-pyrazolo[5,1-a]isoindole (11, 12.5% yield) and trans-3-(4-methylphenyl)-3a,8-dihydro-3H-pyrazolo[5,1-a]isoindole (12, 5% yield). Thermal reactions afforded 3-(4-methylphenyl)-3,3a,8,8a-tetrahydroindeno[2,... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5500642 Wed, 14 Dec 2011 05:00:00 +0100 5500642 http://www.medworm.com/index.php?rid=5500643&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-195.pdf Abstract An efficient synthesis of 1,3-diaryl-4-halo-1H-pyrazoles was achieved. The synthesis involves the [3 + 2] dipolar cycloaddition of 3-arylsydnones and 2-aryl-1,1-dihalo-1-alkenes. The process proceeds smoothly in moderate to excellent yields. 1,3-Diaryl-4-halo-1H-pyrazoles are found to be important intermediates that can easily be converted into 1,2,5-triaryl-substituted pyrazoles via Pd-catalyzed C–H bond activation. Beilstein J. Org. Chem. 2011, 7, 1656–1662. doi:10.3762/bjoc.7.195 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5500643 Mon, 12 Dec 2011 13:30:00 +0100 5500643 http://www.medworm.com/index.php?rid=5492263&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-194.pdf Abstract Herein we describe the application of a monolithic triphenylphosphine reagent to the Appel reaction in flow-chemistry processing, to generate various brominated products with high purity and in excellent yields, and with no requirement for further off-line purification. Beilstein J. Org. Chem. 2011, 7, 1648–1655. doi:10.3762/bjoc.7.194 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5492263 Sun, 11 Dec 2011 05:00:00 +0100 5492263 http://www.medworm.com/index.php?rid=5482560&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-193.pdf Abstract The enzymatic synthesis of tertiary alcohols by the stereospecific oxidation of tertiary alkyl centers is a most-straightforward but challenging approach, since these positions are sterically hindered. In contrast to P450-monooxygenases, there is little known about the potential of non-heme iron(II) oxygenases to catalyze such reactions. We have studied the hydroxylation of trans-3-methyl-L-proline with the α-ketoglutarate (α-KG) dependent oxygenases, cis-3-proline hydroxylase type II and cis-4-proline hydroxylase (cis-P3H_II and cis-P4H). With cis-P3H_II, the tertiary alcohol product (3R)-3-hydroxy-3-methyl-L-proline was obtained exclusively but in reduced yield (~7%) compared to the native substrate L-proline. For cis-P4H, a complete shift in regioselectivity from C-4 ... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5482560 Thu, 08 Dec 2011 05:00:00 +0100 5482560 http://www.medworm.com/index.php?rid=5482561&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-192.pdf Abstract The marine-derived fungus Stachylidium sp. was isolated from the sponge Callyspongia sp. cf. C. flammea. Culture on a biomalt medium supplemented with sea salt led to the isolation of three new phthalide derivatives, i.e., marilones A–C (1–3), and the known compound silvaticol (4). The skeleton of marilones A and B is most unusual, and its biosynthesis is suggested to require unique biochemical reactions considering fungal secondary metabolism. Marilone A (1) was found to have antiplasmodial activity against Plasmodium berghei liver stages with an IC50 of 12.1 µM. Marilone B (2) showed selective antagonistic activity towards the serotonin receptor 5-HT2B with a Ki value of 7.7 µM. Beilstein J. Org. Chem. 2011, 7, 1636–1642. doi:10.3762/bjoc.7.192 ... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5482561 Mon, 05 Dec 2011 14:11:00 +0100 5482561 http://www.medworm.com/index.php?rid=5482562&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-191.pdf Abstract Cyanobacteria are prolific producers of natural products. Investigations into the biochemistry responsible for the formation of these compounds have revealed fascinating mechanisms that are not, or only rarely, found in other microorganisms. In this article, we survey the biosynthetic pathways of cyanobacteria isolated from freshwater, marine and terrestrial habitats. We especially emphasize modular nonribosomal peptide synthetase (NRPS) and polyketide synthase (PKS) pathways and highlight the unique enzyme mechanisms that were elucidated or can be anticipated for the individual products. We further include ribosomal natural products and UV-absorbing pigments from cyanobacteria. Mechanistic insights obtained from the biochemical studies of cyanobacterial pathways can inspire the d... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5482562 Mon, 05 Dec 2011 14:07:00 +0100 5482562 http://www.medworm.com/index.php?rid=5482563&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-190.pdf Beilstein J. Org. Chem. 2011, 7, 1620–1621. doi:10.3762/bjoc.7.190 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5482563 Mon, 05 Dec 2011 14:00:00 +0100 5482563 http://www.medworm.com/index.php?rid=5464696&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-189.pdf Abstract Phenyl 3,4,6-tri-O-benzyl-2-O-(3-carboxypropionyl)-1-thio-β-D-galactopyranoside (1) was condensed via its pentafluorophenyl ester 2 with 5-aminopentyl (4a), 4-aminobutyl (4b), 3-aminopropyl (4c) and 2-aminoethyl 4,6-O-benzylidene-β-D-glucopyranoside (4d), prepared from the corresponding N-Cbz protected glucosides 3a–d, to give the corresponding 2-[3-(alkylcarbamoyl)propionyl] tethered saccharides 5a–d. Intramolecular, ring closing glycosylation of the saccharides with NIS and TMSOTf afforded the tethered β(1→3) linked disaccharides 6a–c, the α(1→3) linked disaccharides 7a–d and the α(1→2) linked disaccharide 8d in ratios depending upon the ring size formed during glycosylation. No β(1→2) linked disacchar... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5464696 Fri, 02 Dec 2011 05:00:00 +0100 5464696 http://www.medworm.com/index.php?rid=5464697&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-188.pdf Abstract Lithiation and subsequent reaction with CO2 was applied to calix[4]arenes with different, equal or mixed, ether functions at the lower-rim site as well as tert-butylated or non-tert-butylated upper-rim positions. Whereas this reaction fails for symmetric calix[4]arene ethers with alkoxy residues greater than methoxy, the carboxylation of mixed methoxy-propoxy calixarene ethers is possible. In connection with this, several new monobridge-substituted calix[4]arenes were characterized with respect to their conformational behaviour in solution and the X-ray crystal structure of one key intermediate is taken into consideration. Beilstein J. Org. Chem. 2011, 7, 1602–1608. doi:10.3762/bjoc.7.188 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5464697 Wed, 30 Nov 2011 10:20:00 +0100 5464697 http://www.medworm.com/index.php?rid=5464698&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-187.pdf Abstract Catalytic direct (hetero)arylation of (hetero)arenes is an attractive alternative to traditional Kumada, Stille, Negishi and Suzuki–Miyaura cross-coupling reactions, notably as it avoids the prior preparation and isolation of (hetero)arylmetals. Developments of this methodology in the oxazole series are reviewed in this article. Methodologies, selectivity, mechanism and future aspects are presented. Beilstein J. Org. Chem. 2011, 7, 1584–1601. doi:10.3762/bjoc.7.187 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5464698 Tue, 29 Nov 2011 11:38:00 +0100 5464698 http://www.medworm.com/index.php?rid=5453784&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-186.pdf Abstract Functionalized phenols based on tyramine were synthesized in order to be selectively grafted on to hexachlorocyclotriphosphazene, affording a variety of functionalized dendrons of type AB5. The B functions comprised fluorescent groups (dansyl) or dyes (dabsyl), whereas the A function was provided by either an aldehyde or an amine. The characterization of these dendrons is reported. An unexpected behaviour of a fluorescent and water-soluble dendron based on dansyl groups in mixtures of dioxane/water was observed. Beilstein J. Org. Chem. 2011, 7, 1577–1583. doi:10.3762/bjoc.7.186 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5453784 Tue, 29 Nov 2011 05:00:00 +0100 5453784 http://www.medworm.com/index.php?rid=5447150&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-185.pdf Abstract A method was developed for the synthesis of α-alkyl, α-aryl-bislactim ethers in good to excellent yields and high diastereoselectivities, consisting of a facile one-pot procedure in which the aryl group is introduced by means of a nucleophilic addition to benzyne and the alkyl group by alkylation of a resultant benzylic anion. Hydrolysis of the sterically less hindered adducts gave the corresponding quaternary amino acids with no racemization, whereas hydrolytic ring opening gave the corresponding valine dipeptides from bulkier bislactims. Beilstein J. Org. Chem. 2011, 7, 1570–1576. doi:10.3762/bjoc.7.185 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5447150 Sat, 26 Nov 2011 05:00:00 +0100 5447150 http://www.medworm.com/index.php?rid=5436906&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-184.pdf Abstract Voltage-clamp experiments of eight oligoester bolaamphiphiles in two subclasses are described. Syntheses of three new terephthalate-based compounds were achieved in three linear steps. Together with five previously described, related compounds, the ion transport activity was assessed by means of the voltage-clamp technique. All of the compounds show multiple types of conductance behavior in planar bilayers, a subset of which was exponentially voltage-dependent. The varied and irregular activities were summarized with the aid of a recently developed “activity-grid” method. Beilstein J. Org. Chem. 2011, 7, 1562–1569. doi:10.3762/bjoc.7.184 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5436906 Wed, 23 Nov 2011 05:00:00 +0100 5436906 http://www.medworm.com/index.php?rid=5436907&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-183.pdf Abstract The impact of the level of complexity in self-sorting was elaborated through the fabrication of various scalene triangles. It turned out that the self-sorting system with a higher level of complexity was far superior to less complex sorting algorithms. Beilstein J. Org. Chem. 2011, 7, 1555–1561. doi:10.3762/bjoc.7.183 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5436907 Tue, 22 Nov 2011 10:17:00 +0100 5436907 http://www.medworm.com/index.php?rid=5436908&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-182.pdf Abstract The potential of appropriately substituted cyclodextrins to act as scavengers for neurotoxic organophosphonates under physiological conditions was evaluated. To this end, a series of derivatives containing substituents with an aldoxime or a ketoxime moiety along the narrow opening of the β-cyclodextrin cavity was synthesized, and the ability of these compounds to reduce the inhibitory effect of the neurotoxic organophosphonate cyclosarin on its key target, acetylcholinesterase, was assessed in vitro. All compounds exhibited a larger effect than native β-cyclodextrin, and characteristic differences were noted. These differences in activity were correlated with the structural and electronic parameters of the substituents. In addition, the relatively strong effect of the cy... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5436908 Tue, 22 Nov 2011 10:13:00 +0100 5436908 http://www.medworm.com/index.php?rid=5436909&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-181.pdf Beilstein J. Org. Chem. 2011, 7, 1541–1542. doi:10.3762/bjoc.7.181 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5436909 Tue, 22 Nov 2011 10:09:00 +0100 5436909 http://www.medworm.com/index.php?rid=5416888&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-180.pdf Abstract A facile synthesis of hitherto unreported 3-(2-benzofuroyl)carbazoles 3a–k, 3,6-bis(2-benzofuroyl)carbazoles 5a–k, and naphtho[2,1-b]furoylcarbazoles 3l and 5l is described. The synthesis mainly relies on the ultrasound-assisted Rap–Stoermer reaction of 3-chloroacetyl- (1) or 3,6-dichloroacetyl-9-ethyl-9H-carbazole (4) with various salicylaldehydes 2a–k as well as 2-hydroxy-1-naphthaldehyde (2l) in CH3CN with the presence of PEG-400 as catalyst. The procedure offers easy access to benzofuroylcarbazoles in short reaction times and the products are obtained in moderate to good yields. Beilstein J. Org. Chem. 2011, 7, 1533–1540. doi:10.3762/bjoc.7.180 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5416888 Thu, 17 Nov 2011 05:00:00 +0100 5416888 http://www.medworm.com/index.php?rid=5416889&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-179.pdf Abstract Pyrazole and benzotriazole-containing thioethers, namely 1,5-bis(3,5-dimethylpyrazol-1-yl)-3-thiapentane, 1,8-bis(3,5-dimethylpyrazol-1-yl)-3,6-dithiaoctane and 1,3-bis(1,2,3-benzotriazol-1-yl)-2-thiapropane were prepared and fully characterized. Oxidation of the pyrazole-containing thioether by hydrogen peroxide proceeds selectively to provide a sulfoxide or sulfone, depending on the amount of oxidant used. Oxidation of the benzotriazole derivative by hydrogen peroxide is not selective, and sulfoxide and sulfone form concurrently. Selenium dioxide-catalyzed oxidation of benzotriazole thioether by H2O2, however, proceeds selectively and yields sulfoxide only. Beilstein J. Org. Chem. 2011, 7, 1526–1532. doi:10.3762/bjoc.7.179 (Source: Beilstein Journal of Organic Chemis... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5416889 Wed, 16 Nov 2011 10:04:00 +0100 5416889 http://www.medworm.com/index.php?rid=5416890&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-178.pdf Abstract Electrophilic gold(I) catalyst 6 competes with GaCl3 as the catalyst of choice in the synthesis of fluoranthenes by intramolecular hydroarylation of alkynes. The potential of this catalyst for the preparation of polyarenes is illustrated by a synthesis of two functionalized decacyclenes in a one-pot transformation in which three C–C bonds are formed with high efficiency. Beilstein J. Org. Chem. 2011, 7, 1520–1525. doi:10.3762/bjoc.7.178 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5416890 Mon, 14 Nov 2011 10:54:00 +0100 5416890 http://www.medworm.com/index.php?rid=5395993&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-177.pdf Abstract In this work we demonstrate chiral recognition of (+)- and (−)-ephedrine using a cyclodextrin-containing polymer. The supramolecular structures obtained by complexation of ephedrine and cyclodextrin were verified by 2-D ROESY NMR measurements. Dynamic light scattering showed clear differences in the mean coil size. Beilstein J. Org. Chem. 2011, 7, 1516–1519. doi:10.3762/bjoc.7.177 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5395993 Fri, 11 Nov 2011 05:00:00 +0100 5395993 http://www.medworm.com/index.php?rid=5395994&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-176.pdf Abstract A ratiometric fluorescent probe based on a Cd2+–ACAQ complex was designed and demonstrated for the chemo- and enantioselective detection of cysteine in 99:1 buffered HEPES:ACN solutions. Under the measuring conditions, the sensor demonstrates high selectivity toward Cys against Hcy and GSH, and an enantioselectivity of 3.35 can be achieved for antipodal forms of Cys. Beilstein J. Org. Chem. 2011, 7, 1508–1515. doi:10.3762/bjoc.7.176 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5395994 Wed, 09 Nov 2011 13:13:00 +0100 5395994 http://www.medworm.com/index.php?rid=5395995&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-175.pdf Abstract An improved total synthesis of (−)-julocrotine in three steps from Cbz-glutamine, in 51% overall yield, is presented. To demonstrate the potential of the heterocyclic moiety for diversity oriented synthesis, a series of (−)-julocrotine analogues was synthesized by employing the heterocyclic precursor as an amino input in Ugi four-component reactions (Ugi-4CR) . Beilstein J. Org. Chem. 2011, 7, 1504–1507. doi:10.3762/bjoc.7.175 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5395995 Mon, 07 Nov 2011 15:43:00 +0100 5395995 http://www.medworm.com/index.php?rid=5374290&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-174.pdf Abstract Based upon a consecutive one-pot Sonogashira–Glaser coupling–cyclization sequence a variety of 2,5-di(hetero)arylthiophenes were synthesized in moderate to good yields. A single Pd/Cu-catalyst system, without further catalyst addition, and easily available, stable starting materials were used, resulting in a concise and highly efficient route for the synthesis of the title compounds. This novel pseudo five-component synthesis starting from iodo(hetero)arenes is particularly suitable as a direct access to well-defined thiophene oligomers, which are of peculiar interest in materials science. Beilstein J. Org. Chem. 2011, 7, 1499–1503. doi:10.3762/bjoc.7.174 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5374290 Fri, 04 Nov 2011 04:00:00 +0100 5374290 http://www.medworm.com/index.php?rid=5374291&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-173.pdf Abstract A high-throughput screening protocol for evaluating chimeric, self-sufficient P450 biocatalysts and their mutants against a panel of substrates was developed, leading to the identification of a number of novel biooxidation activities. Beilstein J. Org. Chem. 2011, 7, 1494–1498. doi:10.3762/bjoc.7.173 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5374291 Wed, 02 Nov 2011 13:25:00 +0100 5374291 http://www.medworm.com/index.php?rid=5374292&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-172.pdf Abstract The application of polystyrene-immobilized proline-based catalysts in packed-bed reactors for the continuous-flow, direct, enantioselective α-aminoxylation of aldehydes is described. The system allows the easy preparation of a series of β-aminoxy alcohols (after a reductive workup) with excellent optical purity and with an effective catalyst loading of ca. 2.5% (four-fold reduction compared to the batch process) working at residence times of ca. 5 min. Beilstein J. Org. Chem. 2011, 7, 1486–1493. doi:10.3762/bjoc.7.172 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5374292 Mon, 31 Oct 2011 10:44:00 +0100 5374292 http://www.medworm.com/index.php?rid=5374293&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-171.pdf Abstract This is a review of our efforts toward the synthesis of a group of natural products that display noteworthy biological activity: Fredericamycin A, nothapodytine B, and topopyrones B and D. In each case, directed aromatic functionalization methodology greatly facilitated the assembly of the key molecular subunits. Beilstein J. Org. Chem. 2011, 7, 1475–1485. doi:10.3762/bjoc.7.171 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5374293 Fri, 28 Oct 2011 13:24:00 +0100 5374293 http://www.medworm.com/index.php?rid=5354746&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-170.pdf Abstract In a simple procedure, the intramolecular hydroarylation of N-propargyl-pyrrole-2-carboxamides was accomplished with the aid of gold(III) catalysis. The reaction led to differently substituted pyrrolo[2,3-c]pyridine and pyrrolo[3,2-c]pyridine derivatives arising either from direct cyclization or from a formal rearrangement of the carboxamide group. Terminal alkynes are essential to achieve bicyclic pyrrolo-fused pyridinones by a 6-exo-dig process, while the presence of a phenyl group at the C–C triple bond promotes the 7-endo-dig cyclization giving pyrrolo-azepines. Beilstein J. Org. Chem. 2011, 7, 1468–1474. doi:10.3762/bjoc.7.170 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5354746 Thu, 27 Oct 2011 22:59:40 +0100 5354746 http://www.medworm.com/index.php?rid=5354747&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-169.pdf Abstract This review highlights the state of the art in the field of coupled chemo(enzymatic) reactions in continuous flow. Three different approaches to such reaction systems are presented herein and discussed in view of their advantages and disadvantages as well as trends for their future development. Beilstein J. Org. Chem. 2011, 7, 1449–1467. doi:10.3762/bjoc.7.169 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5354747 Mon, 24 Oct 2011 13:04:00 +0100 5354747 http://www.medworm.com/index.php?rid=5343140&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-168.pdf Abstract The multistep flow synthesis of vinyl azides and their application in the synthesis of vinyltriazoles is reported. The synthesis relies on a stable polymer-bound equivalent of iodine azide that serves to carry out 1,2-functionalization of alkenes in a telescope flow protocol. The intermediate 2-iodo azides are subjected to a DBU-mediated polymer-supported elimination step yielding vinyl azides in good yield. The third step involves the formation of vinyl triazoles by a copper-catalyzed Huisgen-"click" cycloaddition. The required heat is generated by electromagnetic induction based on copper. Copper serves both as heatable as well as catalytically active packed-bed material inside the flow reactor. Beilstein J. Org. Chem. 2011, 7, 1441–1448. doi:10.3762/bjoc.7... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5343140 Sun, 23 Oct 2011 04:00:00 +0100 5343140 http://www.medworm.com/index.php?rid=5330067&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-167.pdf Abstract 1-Carbamoyl-2-oxopropyl acetate derivatives were synthesized through an acetoxylation process to methylene with the aid of (diacetoxyiodo)benzene (DIB) as the oxidant. Not only mild reaction conditions, but also excellent yields and good substrate scope make the present protocol potentially useful in organic synthesis. Beilstein J. Org. Chem. 2011, 7, 1436–1440. doi:10.3762/bjoc.7.167 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5330067 Wed, 19 Oct 2011 04:00:00 +0100 5330067 http://www.medworm.com/index.php?rid=5330068&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-166.pdf Abstract Titanium-based Lewis acids catalyze the α-fluorination of β-ketoesters by electrophilic N–F-fluorinating reagents. Asymmetric catalysis with TADDOLato–titanium(IV) dichloride (TADDOL = α,α,α',α'-tetraaryl-(1,3-dioxolane-4,5-diyl)-dimethanol) Lewis acids produces enantiomerically enriched α-fluorinated β-ketoesters in up to 91% enantiomeric excess, with either F–TEDA (1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane bis(tetrafluoroborate)) in acetonitrile solution or NFSI (N-fluorobenzenesulfonimide) in dichloromethane solution as fluorinating reagents. The effects of various reaction parameters and of the TADDOL ligand structure on the catalytic activity and enantioselectivity were investigated. The absolute... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5330068 Mon, 17 Oct 2011 14:37:00 +0100 5330068 http://www.medworm.com/index.php?rid=5320972&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-165.pdf Abstract In this contribution we present for the first time a continuous process for the production of highly active Pt catalysts supported by carbon nanotubes by use of an electrically heated tubular reactor. The synthesized catalysts show a high degree of dispersion and narrow distributions of cluster sizes. In comparison to catalysts synthesized by the conventional oil-bath method a significantly higher electrocatalytic activity was reached, which can be attributed to the higher metal loading and smaller and more uniformly distributed Pt particles on the carbon support. Our approach introduces a simple, time-saving and cost-efficient method for fuel cell catalyst preparation in a flow reactor which could be used at a large scale. Beilstein J. Org. Chem. 2011, 7, 1412–1420. d... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5320972 Sun, 16 Oct 2011 04:00:00 +0100 5320972 http://www.medworm.com/index.php?rid=5310366&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-164.pdf Abstract The carboline ring system is an important pharmacophore found in a number of biologically important targets. Development of synthetic routes for the preparation of these compounds is important in order to prepare a range of analogues containing the carboline heterocyclic moiety. A manganese dioxide mediated one-pot method starting with an activated alcohol and consisting of alcohol oxidation, Pictet–Spengler cyclisation, and oxidative aromatisation, offers a convenient process that allows access to β-carbolines. This one-pot process for the preparation of methyl 9H-pyrido[3,4-b]indole-1-carboxylate has subsequently been used as the key step in the synthesis of alangiobussinine and a closely related analogue. Beilstein J. Org. Chem. 2011, 7, 1407–1411. doi:10... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5310366 Thu, 13 Oct 2011 04:00:00 +0100 5310366 http://www.medworm.com/index.php?rid=5310367&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-163.pdf Abstract In the last few years, palladium-mediated three-component synthesis has emerged as an important synthetic methodology to gain access to nitrogen-containing structures. The latest developments in this area are discussed in this review. Beilstein J. Org. Chem. 2011, 7, 1387–1406. doi:10.3762/bjoc.7.163 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5310367 Mon, 10 Oct 2011 13:02:00 +0100 5310367 http://www.medworm.com/index.php?rid=5301481&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-162.pdf Abstract We herein report the synthesis of 3-fluoro-2-methylene-pyrrolidine (3a) and -piperidine (3b) from 1,5- and 1,6-aminoalkynes, respectively, using a combination of a gold-catalyzed hydroamination reaction followed by electrophilic trapping of an intermediate cyclic enamine by Selectfluor. Careful attention was paid to the elucidation of the mechanism and Selectfluor was suggested to play the double role of promoting the oxidation of gold(I) to a gold(III) active species and also the electrophilic fluorination of the enamine intermediates. Beilstein J. Org. Chem. 2011, 7, 1379–1386. doi:10.3762/bjoc.7.162 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5301481 Mon, 10 Oct 2011 04:00:00 +0100 5301481 http://www.medworm.com/index.php?rid=5292382&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-161.pdf Abstract The dictyostatins are powerful microtubule-stabilizing agents that have shown antiproliferative activity against a variety of human cancer cell lines. Two highly active analogs of dictyostatin, 25,26-dihydrodictyostatin and 25,26-dihydro-6-epi-dictyostatin, were prepared by a new streamlined total synthesis route. Three complete carbon fragments were prepared to achieve maximum convergency. These were coupled by a Horner–Wadsworth–Emmons reaction sequence and an esterification. A late stage Nozaki–Hiyama–Kishi reaction was then used to form the 22-membered macrolide. The stereoselectivity of this reaction depended on the configurations of the nearby stereocenter at C6. Beilstein J. Org. Chem. 2011, 7, 1372–1378. doi:10.3762/bjoc.7.161 (Source: B... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5292382 Fri, 07 Oct 2011 04:00:00 +0100 5292382 http://www.medworm.com/index.php?rid=5292383&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-160.pdf Abstract Whilst microwave heating has been widely demonstrated as a synthetically useful tool for rapid reaction screening, a microwave-absorbing solvent is often required in order to achieve efficient reactant heating. In comparison, microreactors can be readily heated and pressurised in order to “super-heat” the reaction mixture, meaning that microwave-transparent solvents can also be employed. To demonstrate the advantages associated with microreaction technology a series of SNAr reactions were performed under continuous flow by following previously developed microwave protocols as a starting point for the investigation. By this approach, an automated microreaction platform (Labtrix® S1) was employed for the continuous flow synthesis of diaryl ethers at 195 °C and ... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5292383 Tue, 04 Oct 2011 14:40:00 +0100 5292383 http://www.medworm.com/index.php?rid=5268025&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-159.pdf Abstract This paper reviews the current trends in the combined use of supported catalytic systems, either on solid supports or in liquid phases and supercritical fluids (scFs), to develop selective and enantioselective chemical transformations under continuous and semi-continuous flow conditions. The results presented have been selected to highlight how the combined use of those two elements can contribute to: (i) Significant improvements in productivity as a result of the enhanced diffusion of substrates and reagents through the interfaces favored by the scF phase; (ii) the long term stability of the catalytic systems, which also contributes to the improvement of the final productivity, as the use of an appropriate immobilization strategy facilitates catalyst isolation and reuse; (iii) th... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5268025 Fri, 30 Sep 2011 04:00:00 +0100 5268025 http://www.medworm.com/index.php?rid=5268026&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-158.pdf Abstract A new phenylethyl alkyl amide, (10R)-10-hydroxy-N-phenethyloctadecanamide (1), was isolated from the beetle Ambrostoma quadriimpressum Motschulsky. The structure of the amide was determined by NMR and MS. The absolute configuration of compound 1 was confirmed by an asymmetric total synthesis, which was started from L-glutamic acid. The construction of the aliphatic chain was accomplished by the selective protection of the hydroxy groups and two-time implementation of the Wittig olefination reaction. Beilstein J. Org. Chem. 2011, 7, 1342–1346. doi:10.3762/bjoc.7.158 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5268026 Thu, 29 Sep 2011 08:54:00 +0100 5268026 http://www.medworm.com/index.php?rid=5268027&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-157.pdf Abstract PEG-embedded potassium tribromide ([K+PEG]Br3−) was found to be an efficient and recyclable catalyst for the synthesis of functionalized piperidines in high yields in a one step, three component coupling between aldehyde, amine and β-keto ester. At the end of the reaction the [K+PEG]Br3− was readily regenerated from the reaction mixture by treating the residue containing [K+PEG]Br− with molecular bromine. Beilstein J. Org. Chem. 2011, 7, 1334–1341. doi:10.3762/bjoc.7.157 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5268027 Wed, 28 Sep 2011 08:27:00 +0100 5268027 http://www.medworm.com/index.php?rid=5256903&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-156.pdf Abstract Diaryl ethers carrying carbamoyloxymethyl groups may be desymmetrised enantio- and diastereoselectively by the use of the sec-BuLi–(−)-sparteine complex in diethyl ether. Enantioselective deprotonation of one of the two benzylic positions leads to atropisomeric products with ca. 80:20 e.r.; an electrophilic quench typically provides functionalised atropisomeric diastereoisomers in up to 97:3 d.r. Beilstein J. Org. Chem. 2011, 7, 1327–1333. doi:10.3762/bjoc.7.156 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5256903 Mon, 26 Sep 2011 23:12:36 +0100 5256903 http://www.medworm.com/index.php?rid=5245814&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-155.pdf Abstract The one-pot cyclization of 5-hexynoic acid to produce 3-alkoxy-2-cyclohexenones proceeds in good yields (58–90%). 3-Hexynoic acid was converted to its acyl chloride with the aid of oxalyl chloride and was cyclized to 3-chloro-2-cyclohexenone upon addition of indium(III) chloride. Subsequent addition of alcohol nucleophiles led to the desired 3-alkoxy-2-cyclohexenones. Beilstein J. Org. Chem. 2011, 7, 1323–1326. doi:10.3762/bjoc.7.155 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5245814 Fri, 23 Sep 2011 04:00:00 +0100 5245814 http://www.medworm.com/index.php?rid=5245815&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-154.pdf Abstract A variety of ortho,ortho'-disubstituted hydrobenzoin derivatives are readily accessible through a directed ortho,ortho'-dimetalation strategy in which the alcohol functions in hydrobenzoin are deprotonated by n-BuLi and the resulting lithium benzyl alkoxides serve as directed metalation groups. The optimization and scope of this reaction are discussed, and the utility of this process is demonstrated in the one-pot preparation of a number of chiral diols as well as a short synthesis of the chiral ligand Vivol. Beilstein J. Org. Chem. 2011, 7, 1315–1322. doi:10.3762/bjoc.7.154 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5245815 Thu, 22 Sep 2011 08:28:00 +0100 5245815 http://www.medworm.com/index.php?rid=5245816&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-153.pdf Abstract Pyrazolidinones were prepared in a two-step sequence starting from α-hydrazonocarboxylic acids. After a four-component Ugi coupling, the resulting hydrazone was engaged in a copper triggered [3 + 2] cycloaddition/aerobic oxidation cascade. Beilstein J. Org. Chem. 2011, 7, 1310–1314. doi:10.3762/bjoc.7.153 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5245816 Wed, 21 Sep 2011 14:35:00 +0100 5245816 http://www.medworm.com/index.php?rid=5245817&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-152.pdf Abstract The method of Kouklovsky and coworkers for the enantioselective alkylation of cyclic N-naphthoyl derivatives of amino acids was used to introduce a 13C label into one of the two enantiotopic methyl groups of 2-aminoisobutyric acid (Aib) by retentive alkylation of L-alanine with 13CH3I. Conditions were identified for optimization of yield and enantiomeric purity, and the absolute configuration of the labelled product was established. Beilstein J. Org. Chem. 2011, 7, 1304–1309. doi:10.3762/bjoc.7.152 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5245817 Tue, 20 Sep 2011 08:47:00 +0100 5245817 http://www.medworm.com/index.php?rid=5232636&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-151.pdf Abstract Complex amino acids with an α-acyloxycarbonyl functionality in the side chain are easily available through epoxide opening by chelated enolates and subsequent oxidation/Passerini reaction. This protocol works with both, aldehyde and ketone intermediates, as long as the ketones are activated by electron-withdrawing groups. In principle Ugi reactions are also possible, allowing the generation of diamino acid derivatives. Beilstein J. Org. Chem. 2011, 7, 1299–1303. doi:10.3762/bjoc.7.151 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5232636 Mon, 19 Sep 2011 04:00:00 +0100 5232636 http://www.medworm.com/index.php?rid=5232637&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-150.pdf Abstract Dihydropyrimidinones and dihydropyrimidinethiones generated from the Biginelli reactions of perfluorooctanesulfonyl-attached benzaldehydes are used as common intermediates for post-condensation modifications such as cycloaddition, Liebeskind–Srogl reaction and Suzuki coupling to form biaryl-substituted dihydropyrimidinone, dihydropyrimidine, and thiazolopyrimidine compounds. The high efficiency of the diversity-oriented synthesis is achieved by conducting a multicomponent reaction for improved atom economy, under microwave heating for fast reaction, and with fluorous solid-phase extractions (F-SPE) for ease of purification. Beilstein J. Org. Chem. 2011, 7, 1294–1298. doi:10.3762/bjoc.7.150 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5232637 Fri, 16 Sep 2011 10:59:00 +0100 5232637 http://www.medworm.com/index.php?rid=5232638&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-149.pdf Abstract The Koch–Haaf reaction of adamantanols was successfully carried out in a microflow system at room temperature. By combining an acid-tolerant hastelloy-made micromixer, a PTFE tube, and a hastelloy-made microextraction unit, a packaged reaction-to-workup system was developed. By means of the present system, the multigram scale synthesis of 1-adamantanecarboxylic acid was achieved in ca. one hour operation. Beilstein J. Org. Chem. 2011, 7, 1288–1293. doi:10.3762/bjoc.7.149 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5232638 Thu, 15 Sep 2011 13:18:00 +0100 5232638 http://www.medworm.com/index.php?rid=5232639&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-148.pdf Abstract Regioselective bromine–lithium exchange reactions on polybrominated biaryls enable the modular synthesis of various polysubstituted biphenyls such as bis(dialkylphosphino)-, bis(diarylphosphino)- and dialkyl(diaryl)phosphinobiphenyls. All permutations of substituents at the ortho positions of the biphenyls are possible. In a similar manner, one can gain access to monophosphine analogues. So far, such a process, based on the effective discrimination between bromine atoms as a function of their chemical environment, has been observed only sporadically. Beilstein J. Org. Chem. 2011, 7, 1278–1287. doi:10.3762/bjoc.7.148 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5232639 Wed, 14 Sep 2011 09:33:00 +0100 5232639 http://www.medworm.com/index.php?rid=5232640&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-147.pdf Abstract In this review we summarize the most important procedures for the preparation of functionalized organzinc and organomagnesium reagents. In addition, new methods for the preparation of polyfunctional aryl- and heteroaryl zinc- and magnesium compounds, as well as new Pd-catalyzed cross-coupling reactions, are reported herein. Experimental details are given for the most important reactions in the of this article. Beilstein J. Org. Chem. 2011, 7, 1261–1277. doi:10.3762/bjoc.7.147 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5232640 Tue, 13 Sep 2011 11:08:00 +0100 5232640 http://www.medworm.com/index.php?rid=5232641&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-146.pdf Abstract A new route to regioselectively dialkoxy-functionalized benzo[b]furan derivatives has been developed from 3-halo-2-iodoanisoles bearing an additional methoxy group, which have been accessed through an ortho-zincation/iodination reaction. Two palladium-catalyzed processes, namely a Sonogashira coupling followed by a tandem hydroxylation/cyclization sequence, give rise to new and interesting dimethoxy-substituted benzo[b]furans. Beilstein J. Org. Chem. 2011, 7, 1255–1260. doi:10.3762/bjoc.7.146 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5232641 Mon, 12 Sep 2011 15:41:00 +0100 5232641 http://www.medworm.com/index.php?rid=5203566&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-145.pdf Abstract A new two-step general approach to [2.2]metacyclophane synthesis from substituted m-xylenes is described. The strategy employs a selective benzylic metalation and oxidative C–C bond formation for both synthetic operations. Regioselective benzylic metalation is achieved using the BuLi, KOt-Bu, TMP(H) (2,2,6,6-tetramethylpiperidine) combination (LiNK metalation conditions) and oxidative coupling with 1,2-dibromoethane. The synthetic ease of this approach compares favourably with previously reported methods and allows for ready access to potentially useful planar chiral derivatives. Beilstein J. Org. Chem. 2011, 7, 1249–1254. doi:10.3762/bjoc.7.145 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5203566 Sun, 11 Sep 2011 02:45:53 +0100 5203566 http://www.medworm.com/index.php?rid=5203567&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-144.pdf Abstract Previously we reported that direct zincation of N,N-dimethylaniline by the mixed-metal zincate reagent 1 ((TMEDA)Na(TMP)(t-Bu)Zn(t-Bu)) surprisingly led to meta-metallation (zincation) of the aniline, as manifested in the crystalline complex 2 ((TMEDA)Na(TMP)(m-C6H4-NMe2)Zn(t-Bu)), and that iodination of these isolated crystals produced the meta-isomer N,N-dimethyl-3-iodoaniline quantitatively. Completing the study here we find that treating the reaction solution with iodine produces a 72% conversion and results in a mixture of regioisomers of N,N-dimethyliodoaniline, with the meta-isomer still the major product (ortho:meta:para ratio, 6:73:21), as determined by NMR. In contrast to this bimetallic method, sodiation of N,N-dimethylaniline with n-BuNa produced the dimeric, ortho-sod... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5203567 Tue, 06 Sep 2011 13:12:00 +0100 5203567 http://www.medworm.com/index.php?rid=5203568&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-143.pdf Abstract A regioselective synthesis of 6-ω-alkenyluridines 3, precursors of potent antiviral and antitumor cyclonucleosides 5, is described. While ω-alkenyl halides do not alkylate 6-lithiouridine, compounds 3 were prepared in a regioselective manner by sequential treatment of 6-methyluridine 2 with LTMP or LDA (4 equiv) in THF at −30 °C followed by alkylation with ω-alkenyl bromides. Beilstein J. Org. Chem. 2011, 7, 1228–1233. doi:10.3762/bjoc.7.143 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5203568 Tue, 06 Sep 2011 13:10:00 +0100 5203568 http://www.medworm.com/index.php?rid=5203569&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-142.pdf Abstract Lithiation of N'-benzyl-N,N-dimethylurea and its substituted derivatives with t-BuLi (3.3 equiv) in anhydrous THF at 0 °C followed by reaction with various electrophiles afforded a range of 3-substituted isoindolin-1-ones in high yields. Beilstein J. Org. Chem. 2011, 7, 1219–1227. doi:10.3762/bjoc.7.142 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5203569 Tue, 06 Sep 2011 13:01:00 +0100 5203569 http://www.medworm.com/index.php?rid=5203570&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-141.pdf Beilstein J. Org. Chem. 2011, 7, 1215–1218. doi:10.3762/bjoc.7.141 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5203570 Tue, 06 Sep 2011 12:58:00 +0100 5203570 http://www.medworm.com/index.php?rid=5190752&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-140.pdf Abstract The conformational properties of 1,3-diindolylureas and thioureas were studied by a combination of heteronuclear NMR spectroscopy and quantum mechanics calculations. NOE experiments showed that the anti–anti conformer along the C7–N7α bonds was predominant in DMSO-d6 solution in the absence of anions. Anion-induced changes in the 1H and 15N chemical shifts confirm the weak binding of chloride anions with negligible conformational changes. Strong deshielding of ureido protons and moderate deshielding of indole NH was observed upon the addition of acetate, benzoate, bicarbonate and dihydrogen phosphate, which indicated that the predominant hydrogen bond interactions occurred at the urea donor groups. Binding of oxo-anions caused conformational changes along the C7&#... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5190752 Sat, 03 Sep 2011 23:00:00 +0100 5190752 http://www.medworm.com/index.php?rid=5190753&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-139.pdf Abstract Gold(I)-N-heterocyclic carbene (NHC) complexes proved to be a reliable catalytic system for the direct synthesis of functionalized γ-vinylbutyrolactones by intramolecular oxaallylic alkylation with primary alcohols. Good isolated chemical yields were obtained for a range of malonyl and acetate derivatives. The good performance in reagent-grade solvents and the functional group/moisture tolerance make this catalytic process a promising route for the synthesis of architecturally complex polycyclic structures. Beilstein J. Org. Chem. 2011, 7, 1198–1204. doi:10.3762/bjoc.7.139 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5190753 Thu, 01 Sep 2011 13:46:00 +0100 5190753 http://www.medworm.com/index.php?rid=5190754&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-138.pdf Abstract Fluorinated and nonfluorinated phosphonates are employed as precatalysts in lithium phosphonate catalyzed cross benzoin couplings. Surprisingly, a decreased catalytic activity for the fluorinated precatalysts compared to the nonfluorinated systems is observed. Furthermore, the ring size of six, seven and nine membered ring catalysts appears not to be crucial for their catalytic activity. Beilstein J. Org. Chem. 2011, 7, 1189–1197. doi:10.3762/bjoc.7.138 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5190754 Wed, 31 Aug 2011 16:11:00 +0100 5190754 http://www.medworm.com/index.php?rid=5173783&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-137.pdf Abstract A convenient synthesis of the tetrasaccharide repeating unit of the O-antigen of Shigella boydii type 9 has been achieved in excellent yield using a [2 + 2] block glycosylation strategy. TEMPO-mediated selective oxidation of the primary alcohol of the tetrasaccharide derivative 8 to the carboxylic group followed by deprotection of the functional groups furnished target tetrasaccharide 1 as its 4-methoxyphenyl glycoside in high yield. Beilstein J. Org. Chem. 2011, 7, 1182–1188. doi:10.3762/bjoc.7.137 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5173783 Mon, 29 Aug 2011 23:00:00 +0100 5173783 http://www.medworm.com/index.php?rid=5168393&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-136.pdf Abstract A novel one-pot four-component synthesis of pyrimidyl- and pyrazolylazulenes through the use of glyoxylation–decarbonylative alkynylation–cyclocondensation sequences starting from azulene or guaiazulene as substrates, gives rise to the formation of the target compounds in moderate to good yields. Beilstein J. Org. Chem. 2011, 7, 1173–1181. doi:10.3762/bjoc.7.136 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5168393 Sat, 27 Aug 2011 23:00:00 +0100 5168393 http://www.medworm.com/index.php?rid=5168394&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-135.pdf Abstract The Eschenmoser coupling is a useful carbon–carbon bond forming reaction which has been used in various different synthesis strategies. The reaction proceeds smoothly if S-alkylated ternary thioamides or thiolactames are used. In the case of S-alkylated secondary thioamides or thiolactames, the Eschenmoser coupling needs prolonged reaction times and elevated temperatures to deliver valuable yields. We have used a flow chemistry system to promote the Eschenmoser coupling under enhanced reaction conditions in order to convert the demanding precursors such as S-alkylated secondary thioamides and thiolactames in an efficient way. Under pressurized reaction conditions at about 220 °C, the desired Eschenmoser coupling products were obtained within 70 s residence time. The rea... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5168394 Thu, 25 Aug 2011 16:44:00 +0100 5168394 http://www.medworm.com/index.php?rid=5154978&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-134.pdf Abstract A triple-channel microreactor fabricated by means of a soft-lithography technique was devised for efficient biphasic gas–liquid reactions. The excellent performance of the microreactor was demonstrated by carrying out photosensitized oxygenations of α-terpinene, citronellol, and allyl alcohols. Beilstein J. Org. Chem. 2011, 7, 1158–1163. doi:10.3762/bjoc.7.134 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5154978 Wed, 24 Aug 2011 23:00:00 +0100 5154978 http://www.medworm.com/index.php?rid=5154979&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-133.pdf Abstract A product-scalable, catalytically mediated flow system has been developed to perform Suzuki–Miyaura reactions under a microwave heating regime, in which the volumetric throughput of a Pd-supported silica monolith can be used to increase the quantity of the product without changing the optimal operating conditions. Two silica monoliths (both 3 cm long), with comparable pore diameters and surface areas, were fabricated with diameters of 3.2 and 6.4 mm to give volumetric capacities of 0.205 and 0.790 mL, respectively. The two monoliths were functionalized with a loading of 4.5 wt % Pd and then sealed in heat-shrinkable Teflon® tubing to form a monolithic flow reactor. The Pd-supported silica monolith flow reactor was then placed into the microwave cavity and connected to a... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5154979 Tue, 23 Aug 2011 10:42:00 +0100 5154979 http://www.medworm.com/index.php?rid=5154980&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-132.pdf Abstract The performance of the ThalesNano H-Cube®, a commercial packed bed flow hydrogenator, was evaluated in the context of small scale reaction screening and optimization. A model reaction, the reduction of styrene to ethylbenzene through a 10% Pd/C catalyst bed, was used to examine performance at various pressure settings, over sequential runs, and with commercial catalyst cartridges. In addition, the consistency of the hydrogen flow was indirectly measured by in-line UV spectroscopy. Finally, system contamination due to catalyst leaching, and the resolution of this issue, is described. The impact of these factors on the run-to-run reproducibility of the H-Cube® reactor for screening and reaction optimization is discussed. Beilstein J. Org. Chem. 2011, 7, 1141–1149.&#... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5154980 Mon, 22 Aug 2011 12:46:00 +0100 5154980 http://www.medworm.com/index.php?rid=5154981&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-131.pdf Abstract The synthesis of new, artificial ribonucleases containing two amino acid residues connected by an aliphatic linker has been developed. Target molecules were synthesized via a catalytic three-component Ugi reaction from aliphatic diisocyanides. Preliminary investigations proved unspecific nuclease activity of the new compounds towards single-stranded RNA and double-stranded circular DNA. Beilstein J. Org. Chem. 2011, 7, 1135–1140. doi:10.3762/bjoc.7.131 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5154981 Fri, 19 Aug 2011 13:15:00 +0100 5154981 http://www.medworm.com/index.php?rid=5154982&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-130.pdf Abstract The release of anthraquinone dyes from β-cyclodextrin modified, hyperbranched polyethylenimine (PEI-CD) was investigated. 5,8-Dichloro-1,4-dihydroxyanthraquinone (AQ-OH) was enclosed simply by ionic attraction between the phenolate groups of AQ-OH and the protonated amino groups of polyethylenimine (PEI). Additionally, the adamantyl moieties of 1,4-bis-N-adamantylaminoanthraquinone (AQ-Ada) were encapsulated by the cavity of CD modified PEI. Due to these different types of interaction, the dyes can be controllably released from the CD-cavity (AQ-Ada) by temperature variation or from salt encapsulation by pH variation (AQ-OH), as monitored by UV–vis spectroscopy. Beilstein J. Org. Chem. 2011, 7, 1130–1134. doi:10.3762/bjoc.7.130 (Source: Beilstein Journal of ... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5154982 Thu, 18 Aug 2011 14:12:00 +0100 5154982 http://www.medworm.com/index.php?rid=5137426&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-129.pdf Abstract Photolysis of aryl azides to give nitrenes, and their subsequent rearrangement in the presence of water to give 3H-azepinones, is performed in continuous flow in a photoreactor constructed of fluorinated ethylene polymer (FEP) tubing. Fine tuning of the reaction conditions using the flow reactor allowed minimization of secondary photochemical reactions. Beilstein J. Org. Chem. 2011, 7, 1124–1129. doi:10.3762/bjoc.7.129 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5137426 Tue, 16 Aug 2011 23:00:00 +0100 5137426 http://www.medworm.com/index.php?rid=5137427&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-128.pdf Abstract Diglycose derivatives, consisting of two monosaccharides linked at non-anomeric positions by a bridging nitrogen atom, have been synthesised. Conversion of one of the precursor monosaccharide coupling components into an unsaturated derivative enhances its electrophilicity at the allylic position, facilitating coupling reactions. Mitsunobu coupling between nosylamides and 2,3-unsaturated-4-alcohols gave the 4-amino-pseudodisaccharides with inversion of configuration as single regio- and diastereoisomers. A palladium-catalysed coupling between an amine and a 2,3-unsaturated 4-trichloroacetimidate gave a 2-amino-pseudodisaccharide as the major product, along with other minor products. Derivatisation of the C=C double bond in pseudodisaccharides allowed the formation of Man(N4–6... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5137427 Tue, 16 Aug 2011 13:18:00 +0100 5137427 http://www.medworm.com/index.php?rid=5129739&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-127.pdf Abstract A microreactor for electrochemical synthesis has been designed and fabricated. It has been shown that different reactions can be carried out successfully using simple protocols. Beilstein J. Org. Chem. 2011, 7, 1108–1114. doi:10.3762/bjoc.7.127 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5129739 Mon, 15 Aug 2011 22:07:03 +0100 5129739 http://www.medworm.com/index.php?rid=5116609&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-126.pdf Abstract The gold(I)/silver(I)-cocatalyzed cascade intermolecular N-Michael addition/intramolecular hydroalkylation reaction offers a simple and efficient method for the synthesis of pyrrolidine derivatives in moderate to excellent product yields and with moderate to good diastereoselectivities. The reaction conditions and the substrate scope of this reaction are examined, and a possible mechanism involving AgClO4 catalyzed intermolecular N-Michael addition and the subsequent gold(I)-catalyzed hydroalkylation is proposed. Beilstein J. Org. Chem. 2011, 7, 1100–1107. doi:10.3762/bjoc.7.126 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5116609 Wed, 10 Aug 2011 23:00:00 +0100 5116609 http://www.medworm.com/index.php?rid=5116610&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-125.pdf Abstract Zinc powder in aqueous alkaline media was employed to perform reductive amination of aldehydes with primary amines. The corresponding secondary amines were obtained in good yields along with minor amounts of hydrodimerization byproducts. The protocol is a green alternative to the use of complex hydrides in chlorinated or highly flammable solvents. Beilstein J. Org. Chem. 2011, 7, 1095–1099. doi:10.3762/bjoc.7.125 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5116610 Wed, 10 Aug 2011 13:19:00 +0100 5116610 http://www.medworm.com/index.php?rid=5116611&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-124.pdf Abstract In the last years there have been extraordinary advances in the development of gold-catalyzed cycloaddition processes. In this review we will summarize some of the most remarkable examples, and present the mechanistic rational underlying the transformations. Beilstein J. Org. Chem. 2011, 7, 1075–1094. doi:10.3762/bjoc.7.124 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5116611 Tue, 09 Aug 2011 14:49:00 +0100 5116611 http://www.medworm.com/index.php?rid=5105877&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-123.pdf Abstract Thirteen difluoromethyl-containing pseudopeptides were synthesized by Ugi reaction using the novel building block 2,2-difluoro-2-(phenylthio)acetic acid (2) as one component, followed by removal of the phenylsulfanyl protecting group in the presence of tributyltin hydride and azobisisobutyronitrile. Beilstein J. Org. Chem. 2011, 7, 1070–1074. doi:10.3762/bjoc.7.123 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5105877 Sun, 07 Aug 2011 23:00:00 +0100 5105877 http://www.medworm.com/index.php?rid=5093805&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-122.pdf Abstract The use of FeCl3 resulted in a fast homocoupling of aryllithiums, and this enabled its integration with the halogen–lithium exchange reaction of aryl halides in a flow microreactor. This system allows the homocoupling of two aryl halides bearing electrophilic functional groups, such as CN and NO2, in under a minute. Beilstein J. Org. Chem. 2011, 7, 1064–1069. doi:10.3762/bjoc.7.122 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5093805 Wed, 03 Aug 2011 23:00:00 +0100 5093805 http://www.medworm.com/index.php?rid=5093806&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-121.pdf Abstract A series of 4,4'-dimethoxybenzophenone mediated intra- and intermolecular photodecarboxylation reactions involving phthalimides have been examined under microflow conditions. Conversion rates, isolated yields and chemoselectivities were compared to analogous reactions in a batch photoreactor. In all cases investigated, the microreactions gave superior results thus proving the superiority of microphotochemistry over conventional technologies. Beilstein J. Org. Chem. 2011, 7, 1055–1063. doi:10.3762/bjoc.7.121 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5093806 Tue, 02 Aug 2011 10:16:00 +0100 5093806 http://www.medworm.com/index.php?rid=5093807&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-120.pdf Abstract 4-Fluoropyrazole systems may be prepared by a single, sequential telescoped two-step continuous gas/liquid–liquid/liquid flow process from diketone, fluorine gas and hydrazine starting materials. Beilstein J. Org. Chem. 2011, 7, 1048–1054. doi:10.3762/bjoc.7.120 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5093807 Tue, 02 Aug 2011 10:09:00 +0100 5093807 http://www.medworm.com/index.php?rid=5093808&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-119.pdf Beilstein J. Org. Chem. 2011, 7, 1046–1047. doi:10.3762/bjoc.7.119 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5093808 Tue, 02 Aug 2011 10:03:00 +0100 5093808 http://www.medworm.com/index.php?rid=5075949&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-118.pdf Abstract Efficient and stereoselective syntheses are described for the preparation of 2,3,9,10-tetrabromo-1,4-dimethoxy-1,2,3,4-tetrahydroanthracenes 7, 8 and the corresponding 1,4-diol 17 by silver ion-assisted solvolysis of hexabromotetrahydroanthracene 6. Base-promoted aromatization of 7 and 8 afforded synthetically valuable tribromo-1-methoxyanthracenes 10 and 11. The reaction of 17 with sodium methoxide generated tribromodihydroanthracene-1,4-diol 27, whose oxidation with PCC gave 2,9,10-tribromoanthracene-1,4-dione (28). Therefore a selective and efficient method was developed for the preparation of compound 28 starting from 9,10-dibromoanthracene (1), in a simple four-step process. Compounds 10 and 11, and diol 27 constitute key precursors for the preparation of functionalized subst... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5075949 Fri, 29 Jul 2011 23:00:00 +0100 5075949 http://www.medworm.com/index.php?rid=5068320&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-117.pdf Abstract Aminoacyl p-nitroaniline (aminoacyl-pNA) and aminoacyl 7-amino-4-methylcoumarin (aminoacyl-AMC) are important synthons for the synthesis of chromogenic/fluorogenic protease substrates. A new efficient method was developed to synthesize aminoacyl-pNA and aminoacyl-AMC derivatives in excellent yields starting from either amino acids or their corresponding commercially available N-hydroxysuccinimide esters. The method involved the in situ formation of selenocarboxylate intermediate of protected amino acids and the subsequent non-nucleophilic amidation with an azide. Common protecting groups used in amino acid/peptide chemistry were all well-tolerated. The method was also successfully applied to the synthesis of a dipeptide conjugate, indicating that the methodology is applicable to t... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5068320 Tue, 26 Jul 2011 23:00:00 +0100 5068320 http://www.medworm.com/index.php?rid=5068322&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-116.pdf Abstract A comprehensive study on the asymmetric gold-catalyzed cycloisomerization reaction of heteroatom tethered 1,6-enynes is described. The cycloisomerization reactions were conducted in the presence of the chiral cationic Au(I) catalyst consisting of (R)-4-MeO-3,5-(t-Bu)2-MeOBIPHEP-(AuCl)2 complex and silver salts (AgOTf or AgNTf2) in toluene under mild conditions to afford functionalized bicyclo[4.1.0]heptene derivatives. The reaction conditions were found to be highly substrate-dependent, the best results being obtained in the case of oxygen-tethered enynes. The formation of bicyclic derivatives, including cyclopropyl pentasubstituted ones, was reported in moderate to good yields and in enantiomeric excesses up to 99%. Beilstein J. Org. Chem. 2011, 7, 1021–1029. doi:10.3... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5068322 Tue, 26 Jul 2011 13:00:00 +0100 5068322 http://www.medworm.com/index.php?rid=5061253&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-115.pdf Abstract Triazole–Au (TA–Au) catalysts were employed in several transformations involving propargyl ester rearrangement. Good chemoselectivity was observed, which allowed the effective activation of the alkyne without affecting the reactivity of the allene ester intermediates. These results led to the investigation of the preparation of allene ester intermediates with TA–Au catalysts under anhydrous conditions. As expected, the desired 3,3-rearrangement products were obtained in excellent yields (generally >90% yields with 1% loading). Besides the typical ester migrating groups, carbonates and carbamates were also found to be suitable for this transformation, which provided a highly efficient, practical method for the preparation of substituted allenes. Beilstein J. O... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5061253 Sun, 24 Jul 2011 23:00:00 +0100 5061253 http://www.medworm.com/index.php?rid=5057008&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-114.pdf Abstract The rapid synthesis of bicyclo[m.n.1]alkanone cores possessing quaternary carbon centers adjacent to a bridged ketone represents a significant synthetic challenge. This type of architectural feature is embedded in various complex biologically active compounds such as hyperforin and garsubellin A. Herein, we report a highly diastereoselective one-pot Diels–Alder reaction/Au(I)-catalyzed carbocyclization to generate bicyclo[3.3.1]alkanones in yields ranging from 48–93%. Beilstein J. Org. Chem. 2011, 7, 1007–1013. doi:10.3762/bjoc.7.114 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5057008 Sat, 23 Jul 2011 23:00:00 +0100 5057008 http://www.medworm.com/index.php?rid=5047789&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-113.pdf Abstract 1-Cyclopropylcyclopropanecarboxylic acid (2), which is accessible on a large scale (900 mmol) from 1-bromo-1-cyclopropylcyclopropane (1) in 64% yield (89% on a 12.4 mmol scale), has been subjected to a Curtius degradation employing the Weinstock protocol to furnish the N-Boc-protected (1-cyclopropyl)cyclopropylamine 3 (76%). Deprotection of 3 with hydrogen chloride in diethyl ether gave the (1-cyclopropyl)cyclopropylamine hydrochloride (4·HCl) in 87% yield. Beilstein J. Org. Chem. 2011, 7, 1003–1006. doi:10.3762/bjoc.7.113 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5047789 Thu, 21 Jul 2011 23:00:00 +0100 5047789 http://www.medworm.com/index.php?rid=5047790&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-112.pdf Abstract A practical route to tertiary diarylmethylamides or -carbamates from imines, organozinc reagents and acyl chlorides or chloroformates is described. This route involves the formation of an imine, which is used without isolation, followed by its activation by the carbonyl-containing electrophile and the trapping of the acyliminium by an organozinc reagent. Most steps are conducted concomitantly to render the procedure as practical and straightforward as possible. Therefore, the whole experimental protocol takes less than two hours. Beilstein J. Org. Chem. 2011, 7, 997–1002. doi:10.3762/bjoc.7.112 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5047790 Wed, 20 Jul 2011 13:55:00 +0100 5047790 http://www.medworm.com/index.php?rid=5047791&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-111.pdf Abstract The synthesis of a GSK 2nd generation inhibitor of the hepatitis C virus, by enantioselective 1,3-dipolar cycloaddition between a leucine derived iminoester and tert-butyl acrylate, was studied. The comparison between silver(I) and gold(I) catalysts in this reaction was established by working with chiral phosphoramidites or with chiral BINAP. The best reaction conditions were used for the total synthesis of the hepatitis C virus inhibitor by a four step procedure affording this product in 99% ee and in 63% overall yield. The origin of the enantioselectivity of the chiral gold(I) catalyst was justified according to DFT calculations, the stabilizing coulombic interaction between the nitrogen atom of the thiazole moiety and one of the gold atoms being crucial. Beilstein J. Org. Chem... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5047791 Tue, 19 Jul 2011 09:56:00 +0100 5047791 http://www.medworm.com/index.php?rid=5026534&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-110.pdf Abstract The tetrahydroquinolines obtained through the Povarov multicomponent reaction have been oxidized to the corresponding quinoline, giving access to a single product through a two-step sequence. Several oxidizing agents were studied and manganese dioxide proved to be the reagent of choice, affording higher yields, cleaner reactions and practical protocols. Beilstein J. Org. Chem. 2011, 7, 980–987. doi:10.3762/bjoc.7.110 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5026534 Wed, 13 Jul 2011 23:00:00 +0100 5026534 http://www.medworm.com/index.php?rid=5026535&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-109.pdf Abstract The Ugi reaction of 2-substituted dihydrobenzoxazepines was found to proceed with unexpectedly good diastereoselectivitiy (diastereoisomeric ratios up to 9:1), despite the large distance between the pre-existing stereogenic centre and the newly generated one. This result represents the first good 1,4 asymmetric induction in an Ugi reaction as well as the first example of diastereoselective Ugi reaction of seven membered cyclic imines. It allows the diversity-oriented synthesis of various tetrahydro[f][1,4]benzoxazepines. Beilstein J. Org. Chem. 2011, 7, 976–979. doi:10.3762/bjoc.7.109 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5026535 Wed, 13 Jul 2011 11:32:00 +0100 5026535 http://www.medworm.com/index.php?rid=5026536&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-108.pdf Abstract A practical approach to highly functionalized 4-hydroxypyridine derivatives with stereogenic side chains in the 2- and 6-positions is described. The presented two-step process utilizes a multicomponent reaction of alkoxyallenes, nitriles and carboxylic acids to provide β-methoxy-β-ketoenamides which are transformed into 4-hydroxypyridines in a subsequent cyclocondensation. The process shows broad substrate scope and leads to differentially substituted enantiopure pyridines in good to moderate yields. The preparation of diverse substituted lactic acid derived pyrid-4-yl nonaflates is described. Additional evidence for the postulated mechanism of the multicomponent reaction is presented. Beilstein J. Org. Chem. 2011, 7, 962–975. doi:10.3762/bjoc.7.108 (Source: ... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5026536 Wed, 13 Jul 2011 11:24:00 +0100 5026536 http://www.medworm.com/index.php?rid=5026537&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-107.pdf Beilstein J. Org. Chem. 2011, 7, 960–961. doi:10.3762/bjoc.7.107 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5026537 Wed, 13 Jul 2011 11:16:00 +0100 5026537 http://www.medworm.com/index.php?rid=5017293&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-106.pdf Abstract The gold-catalyzed, seven-membered ring forming, intramolecular hydroamination of alkynic sulfonamides has been investigated. The protocol, with a semihollow-shaped triethynylphosphine as a ligand for gold, allowed the synthesis of a variety of azepine derivatives, which are difficult to access by other methods. Both alkynic sulfoamides with a flexible linear chain and the benzene-fused substrates underwent 7-exo-dig cyclization to afford the nitrogen-containing heterocyclic seven-membered rings, such as tetrahydroazepine and dihydrobenzazepine, in good yields. Beilstein J. Org. Chem. 2011, 7, 951–959. doi:10.3762/bjoc.7.106 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5017293 Mon, 11 Jul 2011 23:00:00 +0100 5017293 http://www.medworm.com/index.php?rid=5005857&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-105.pdf Abstract It has been established that a cationic gold(I)/(R)-DTBM-Segphos or (R)-BINAP complex catalyzes the atropselective intramolecular hydroarylation of alkynes leading to enantioenriched axially chiral 4-aryl-2-quinolinones and 4-arylcoumarins with up to 61% ee. Beilstein J. Org. Chem. 2011, 7, 944–950. doi:10.3762/bjoc.7.105 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5005857 Wed, 06 Jul 2011 23:00:00 +0100 5005857 http://www.medworm.com/index.php?rid=5005858&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-104.pdf Abstract The synthesis of a model endocyclic allene related to the vernonia allenes is described. Fragmentation of a suitable decalin derivative gave the simplified germacrane scaffold. Computational analysis of this and related substrates provides insight into the stereoelectronic requirements of C–C fragmentation. The overall strategy to access these and other sesquiterpenes and the key steps in the present sequence are also discussed. Beilstein J. Org. Chem. 2011, 7, 937–943. doi:10.3762/bjoc.7.104 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=5005858 Tue, 05 Jul 2011 13:11:00 +0100 5005858 http://www.medworm.com/index.php?rid=4997053&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-103.pdf Abstract C–O, C–N and C–C bonds are the most widespread types of bonds in nature, and are the cornerstone of most organic compounds, ranging from pharmaceuticals and agrochemicals to advanced materials and polymers. Cationic gold acts as a soft and carbophilic Lewis acid and is considered one of the most powerful activators of C–C multiple bonds. Consequently, gold-catalysis plays an important role in the development of new strategies to form these bonds in more convenient ways. In this review, we highlight recent advances in the gold-catalyzed chemistry of addition of X–H (X = O, N, C) bonds to C–C multiple bonds, tandem reactions, and asymmetric additions. This review covers gold-catalyzed organic reactions published from 2008 to the present. Beilstei... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4997053 Mon, 04 Jul 2011 22:45:30 +0100 4997053 http://www.medworm.com/index.php?rid=4991249&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-102.pdf Abstract The role of silver additives is examined in the context of gold-mediated functionalisation of aromatic C–H bonds. Doubt is cast on the commonly cited route of halide abstraction from gold and evidence of substrate activation is given. Beilstein J. Org. Chem. 2011, 7, 892–896. doi:10.3762/bjoc.7.102 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4991249 Fri, 01 Jul 2011 23:00:00 +0100 4991249 http://www.medworm.com/index.php?rid=4991250&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-101.pdf Abstract Potassium thiocyanate acts as an efficient sulfur surrogate in C–S cross-coupling reactions mediated by recyclable copper oxide nanoparticles under ligand free conditions. This protocol avoids foul smelling thiols, for the synthesis of a variety of symmetrical diaryl sulfides, via the cross-coupling of different aryl halides with potassium thiocyanate, affording corresponding products in moderate to excellent yields. Beilstein J. Org. Chem. 2011, 7, 886–891. doi:10.3762/bjoc.7.101 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4991250 Thu, 30 Jun 2011 07:24:00 +0100 4991250 http://www.medworm.com/index.php?rid=4983007&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-100.pdf Abstract A series of ynenyl allyl ethers were rearranged into polysubstituted furans in the presence of a gold(I) catalyst. It is proposed that the transformation involves a Claisen-type rearrangement that allows the efficient creation of quaternary centers under mild experimental conditions. Beilstein J. Org. Chem. 2011, 7, 878–885. doi:10.3762/bjoc.7.100 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4983007 Wed, 29 Jun 2011 23:00:00 +0100 4983007 http://www.medworm.com/index.php?rid=4974435&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-99.pdf Abstract This personal account summarizes our recent developments in gold-catalyzed direct substitutions on propargylic (allylic, benzylic) alcohols, with various nucleophiles (and bi-nucleophiles) based on the σ- and/or π-acidity of gold(III) complexes. Synthetic developments are also briefly described. Beilstein J. Org. Chem. 2011, 7, 866–877. doi:10.3762/bjoc.7.99 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4974435 Mon, 27 Jun 2011 23:00:00 +0100 4974435 http://www.medworm.com/index.php?rid=4967205&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-98.pdf Abstract A gold-catalyzed oxidation of arylallenes to form α-diketones and aldehydes in good yields is presented. Further directed synthesis of quinoxalines and benzimidazoles, via the condensation of the resulting α-diketones and aldehydes with benzene-1,2-diamine, was achieved in high yields. Beilstein J. Org. Chem. 2011, 7, 860–865. doi:10.3762/bjoc.7.98 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4967205 Sat, 25 Jun 2011 23:00:00 +0100 4967205 http://www.medworm.com/index.php?rid=4959035&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-97.pdf Abstract Gold catalysis has emerged as one of the most dynamic fields in organic synthesis. Only recently, more and more domino processes, for which gold pre-catalysts were found to be outstandingly effective, were paralleled by employing iodine electrophiles in place of gold compounds. This review highlights how, in certain cases, iodonium activation can match gold-catalyzed reactions to construct identical product scaffolds. Likewise, processes are discussed where mostly identical starting materials are transformed into diverse frameworks depending on whether gold or iodonium activation was used to trigger the reaction. Beilstein J. Org. Chem. 2011, 7, 847–859. doi:10.3762/bjoc.7.97 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4959035 Wed, 22 Jun 2011 23:00:00 +0100 4959035 http://www.medworm.com/index.php?rid=4951008&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-96.pdf Abstract Isotopic labelling studies were performed to probe a proposed 1,2-aryl shift in the gold-catalysed cycloisomerisation of alkynyl aziridines into 2,4-disubstituted pyrroles. Two isotopomers of the expected skeletal rearrangement product were identified using 13C-labelling and led to a revised mechanism featuring two distinct skeletal rearrangements. The mechanistic proposal has been rationalised against the reaction of a range of 13C- and deuterium-labelled substrates. Beilstein J. Org. Chem. 2011, 7, 839–846. doi:10.3762/bjoc.7.96 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4951008 Mon, 20 Jun 2011 23:00:00 +0100 4951008 http://www.medworm.com/index.php?rid=4951009&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-95.pdf Abstract A novel synthetic methodology has been developed for the synthesis of diethyl 5-alkyl/aryl/heteroaryl substituted 3,4-dihydro-2H-pyrrole-4,4-dicarboxylates (also called 2-substituted pyrroline-4,5-dihydro-3,3-dicarboxylic acid diethyl esters) by iodide ion induced ring expansion of 2-[(aziridin-1-yl)-1-alkyl/aryl/heteroaryl-methylene]malonic acid diethyl esters in very good to excellent yields under mild reaction conditions. The electronic and steric impact of the substituents on the kinetics of ring expansion of N-vinyl aziridines to pyrrolines has been studied. Various diversely substituted novel pyrroline derivatives have been synthesized by this methodology and the products can be used as key intermediates in the synthesis of substituted pyrrolines, pyrroles and pyrrolidines. ... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4951009 Mon, 20 Jun 2011 16:15:00 +0100 4951009 http://www.medworm.com/index.php?rid=4943992&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-94.pdf Abstract The one-pot hydrozirconation of allenes and nitriles followed by an in situ transmetalation of the allylzirconocene with dimethylzinc or zinc chloride provides functionalized homoallylic amines. An intramolecular version of this process leads to 3-aminotetrahydrofurans and 3-aminotetrahydropyrans. Beilstein J. Org. Chem. 2011, 7, 824–830. doi:10.3762/bjoc.7.94 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4943992 Sat, 18 Jun 2011 23:00:00 +0100 4943992 http://www.medworm.com/index.php?rid=4931522&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-93.pdf Abstract Hybrid molecules combining photoactivated aryl acetylenes and a dicationic lysine moiety cause the most efficient double-strand (ds) DNA cleavage known to date for a small molecule. In order to test the connection between the alkylating ability and the DNA-damaging properties of these compounds, we investigated the photoreactivity of three isomeric aryl–tetrafluoropyridinyl (TFP) alkynes with amide substituents in different positions (o-, m-, and p-) toward a model π-system. Reactions with 1,4-cyclohexadiene (1,4-CHD) were used to probe the alkylating properties of the triplet excited states in these three isomers whilst Stern–Volmer quenching experiments were used to investigate the kinetics of photoinduced electron transfer (PET). The three analogous isomeric ly... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4931522 Wed, 15 Jun 2011 23:00:00 +0100 4931522 http://www.medworm.com/index.php?rid=4931523&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-92.pdf Abstract A straightforward, efficient, and reliable redox catalyst system for the Au(I)/Au(III)-catalyzed Sonogashira cross-coupling reaction of functionalized terminal alkynes with arylboronic acids under mild conditions has been developed. Beilstein J. Org. Chem. 2011, 7, 808–812. doi:10.3762/bjoc.7.92 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4931523 Wed, 15 Jun 2011 15:03:00 +0100 4931523 http://www.medworm.com/index.php?rid=4931524&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-91.pdf Abstract The Au(I)-catalyzed cyclization of hydroxyallylic ethers to form tetrahydropyrans is reported. Employing (acetonitrile)[(o-biphenyl)di-tert-butylphosphine]gold(I) hexafluoroantimonate, the cyclization reactions were complete within minutes to hours, depending on the substrate. The reaction progress was monitored by GC, and comparisons between substrates demonstrate that reactions of allylic alcohols are faster than the corresponding ethers. Additionally, it is reported that Reaxa QuadraPureTM MPA is an efficient scavenging reagent that halts the reaction progress. Beilstein J. Org. Chem. 2011, 7, 802–807. doi:10.3762/bjoc.7.91 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4931524 Tue, 14 Jun 2011 13:43:00 +0100 4931524 http://www.medworm.com/index.php?rid=4919719&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-90.pdf Abstract Efforts to trap early intermediates of the gold-catalyzed phenol synthesis failed. Neither inter- nor intramolecularly offered vinyl groups, ketones or alcohols were able to intercept the gold carbenoid species. This indicates that the competing steps of the gold-catalyzed phenol synthesis are much faster than the steps of the interception reaction. In the latter the barrier of activation is higher. At the same time this explains the high tolerance of this very efficient and general reaction towards functional groups. Beilstein J. Org. Chem. 2011, 7, 794–801. doi:10.3762/bjoc.7.90 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4919719 Fri, 10 Jun 2011 23:00:00 +0100 4919719 http://www.medworm.com/index.php?rid=4919720&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-89.pdf Abstract The selectivity of our previously described gold-catalyzed tandem reaction, 1,2-indole migration followed by aura-iso-Nazarov cyclization, of 3-propargylindoles bearing (hetero)aromatic substituents at both the propargylic and terminal positions, was reversed by the proper choice of the catalyst and the reaction conditions. Thus, 3-(inden-2-yl)indoles, derived from an aura-Nazarov cyclization (instead of an aura-iso-Nazarov cyclization), were obtained in moderate to good yields from a variety of 3-propargylindoles. Beilstein J. Org. Chem. 2011, 7, 786–793. doi:10.3762/bjoc.7.89 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4919720 Thu, 09 Jun 2011 14:51:00 +0100 4919720 http://www.medworm.com/index.php?rid=4910058&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-88.pdf Abstract A highly efficient gold(I)-catalyzed Overman rearrangement of allylic trichloroacetimidates to allylic trichloroacetamides in water is reported. With this environmentally benign and scalable protocol, a series of C3-alkyl substituted allylic trichloroacetamides were synthesized in good to high yields. Beilstein J. Org. Chem. 2011, 7, 781–785. doi:10.3762/bjoc.7.88 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4910058 Wed, 08 Jun 2011 22:23:18 +0100 4910058 http://www.medworm.com/index.php?rid=4910059&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-87.pdf Abstract The development of new methodologies catalyzed by late transition metals involving cycloisomerizations of strained rings can open new venues for the synthesis of structurally complex molecules with interesting biological activities. Herein we summarize, from both a synthetic as well as a mechanistic point of view, the most recent developments in gold-catalyzed ring expansions. Beilstein J. Org. Chem. 2011, 7, 767–780. doi:10.3762/bjoc.7.87 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4910059 Tue, 07 Jun 2011 15:22:00 +0100 4910059 http://www.medworm.com/index.php?rid=4900864&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-86.pdf Abstract The first synthesis of α-(trifluoromethyl)-β-lactam ((S)-1) is reported. The route starts from α-(trifluoromethyl)acrylic acid (2). Conjugate addition of α-(p-methoxyphenyl)ethylamine ((S)-3b), generated an addition adduct 4b which was cyclised to β-lactam 5b. Separation of the diastereoisomers by chromatography gave ((αS,3S)-5b). N-Debenzylation afforded the desired α-(trifluoromethyl)-β-lactam ((S)-1). The absolute stereochemistry of diastereoisomers 5 was determined by X-ray crystallographic determination of a close structural analogue, (αS,3S)-5c, and then 1H and 19F NMR correlation to the individual diastereoisomers of 5a and 5b. Beilstein J. Org. Chem. 2011, 7, 759–766. doi:10.3762/bjoc.7.86 (Source: Beilstein Journal ... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4900864 Sun, 05 Jun 2011 23:00:00 +0100 4900864 http://www.medworm.com/index.php?rid=4900865&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-85.pdf Abstract A broad perspective of various factors influencing alkene selenenylation has been developed by concurrent detailed analysis of key experimental and theoretical data, such as asymmetric induction, stereochemistry, relative reactivities, and comparison with that of alkene sulfenylation. Alkyl group branching α to the double bond was shown to have the greatest effect on alkene reactivity and the stereochemical outcome of corresponding addition reactions. This is in sharp contrast with other additions to alkenes, which depend more on the degree of substitution on C=C or upon substituent electronic effects. Electronic and steric effects influencing asymmetric induction, stereochemistry, regiochemistry, and relative reactivities in the addition of PhSeOTf to alkenes are compared an... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4900865 Fri, 03 Jun 2011 10:22:00 +0100 4900865 http://www.medworm.com/index.php?rid=4891197&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-84.pdf Abstract An efficient formal total synthesis of (±)-clavukerin A was accomplished via a gold-catalyzed cycloisomerization of a 3-methoxy-1,6-enyne 5 as the key strategy followed by Rh-catalyzed stereoselective hydrogenation of the cycloheptenone 4. Beilstein J. Org. Chem. 2011, 7, 740–743. doi:10.3762/bjoc.7.84 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4891197 Thu, 02 Jun 2011 23:00:00 +0100 4891197 http://www.medworm.com/index.php?rid=4882519&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-83.pdf Abstract Continuous flow systems for hydrogenation using polysilane-supported palladium/alumina (Pd/(PSi–Al2O3)) hybrid catalysts were developed. Our original Pd/(PSi–Al2O3) catalysts were used successfully in these systems and the hydrogenation of unsaturated C–C bonds and a nitro group, deprotection of a carbobenzyloxy (Cbz) group, and a dehalogenation reaction proceeded smoothly. The catalyst retained high activity for at least 8 h under neat conditions. Beilstein J. Org. Chem. 2011, 7, 735–739. doi:10.3762/bjoc.7.83 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4882519 Tue, 31 May 2011 22:24:36 +0100 4882519 http://www.medworm.com/index.php?rid=4882520&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-82.pdf Abstract Cyclopropenes as substrates entered the field of gold catalysis in 2008 and have proven to be valuable partners in a variety of gold-catalyzed reactions. The different contributions in this growing research area are summarized in this review. Beilstein J. Org. Chem. 2011, 7, 717–734. doi:10.3762/bjoc.7.82 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4882520 Mon, 30 May 2011 14:36:00 +0100 4882520 http://www.medworm.com/index.php?rid=4870353&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-81.pdf Abstract By focusing on recent developments on natural and non-natural azasugars (iminocyclitols), this review bolsters the case for the role of olefin metathesis reactions (RCM, CM) as key transformations in the multistep syntheses of pyrrolidine-, piperidine- and azepane-based iminocyclitols, as important therapeutic agents against a range of common diseases and as tools for studying metabolic disorders. Considerable improvements brought about by introduction of one or more metathesis steps are outlined, with emphasis on the exquisite steric control and atom-economical outcome of the overall process. The comparative performance of several established metathesis catalysts is also highlighted. Beilstein J. Org. Chem. 2011, 7, 699–716. doi:10.3762/bjoc.7.81 (Source: Beilstein Jo... Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4870353 Thu, 26 May 2011 23:00:00 +0100 4870353 http://www.medworm.com/index.php?rid=4870354&cid=s_34014_59_f&fid=34014&url=http%3A%2F%2Fwww.beilstein-journals.org%2Fbjoc%2Fcontent%2Fpdf%2F1860-5397-7-80.pdf Abstract This review article summarizes the results of a long-term investigation of 5-alkoxymethyluracil analogues and is aimed, in particular, at methods of syntheses. Most of the presented compounds were synthesized in order to evaluate their biological activity, therefore, a brief survey of biological activity, especially antiviral, cytotoxic and antibacterial, is also reported. Beilstein J. Org. Chem. 2011, 7, 678–698. doi:10.3762/bjoc.7.80 (Source: Beilstein Journal of Organic Chemistry) Beilstein Journal of Organic Chemistry journals http://www.medworm.com/rss/comments.php?id=4870354 Thu, 26 May 2011 14:50:00 +0100 4870354