Organocatalyzed Asymmetric Conjugate Addition of Alcohols to β-Fluoroalkyl Vinylsulfones by Bifunctional Phosphonium Salt Catalyst
Chemistry. 2024 May 2:e202401325. doi: 10.1002/chem.202401325. Online ahead of print.ABSTRACTChiral secondary alcohols, serving as essential structural motifs, hold significant potential for diverse applications. The exploration of effective synthetic strategies toward these compounds is both attractive and challenging. Herein, we present an asymmetric oxa-Michael reaction involving aliphatic alcohols as nucleophiles and β-fluoroalkyl vinylsulfones catalyzed by bifunctional phosphonium salt (BPS), achieving high yields and excellent enantioselectivities (up to 98% yield and 98% ee). Additionally, a sequential process incl...
Source: Chemistry - May 3, 2024 Category: Chemistry Authors: Xingjie Luo Zhiyu Jiang Siqun Yang Xiaoyu Ren Tianli Wang Source Type: research
A Cu/MnOx Composite with Copper-Doping-Induced Oxygen Vacancies as a Cathode for Aqueous Zinc-Ion Batteries
Chemistry. 2024 May 3:e202401463. doi: 10.1002/chem.202401463. Online ahead of print.ABSTRACTAqueous zinc-ion batteries are anticipated to be the next generation of important energy storage devices to replace lithium-ion batteries due to the ongoing use of lithium resources and the safety hazards associated with organic electrolytes in lithium-ion batteries. Manganese-based compounds, including MnOx materials, have prominent places among the many zinc-ion battery cathode materials. Additionally, Cu doping can cause the creation of an oxygen vacancy, which increases the material's internal electric field and enhances cycle ...
Source: Chemistry - May 3, 2024 Category: Chemistry Authors: Miao Han Hongsheng Jia Yubo Wang Siqi Li Yuanlong E Yanqing Liu Qingshuang Wang Wanqiang Liu Source Type: research
Alkene Cross-Metathesis with 2,5-Dimethyl-2,4-Hexadiene Enables Isobutylenyl / Prenyl Functionalizations and Rubber Valorization
Chemistry. 2024 May 3:e202400860. doi: 10.1002/chem.202400860. Online ahead of print.ABSTRACT2,5-Dimethyl-2,4-hexadiene is a readily available and easily managable compound, whose symmetric and polymethylated dienic structure should be prone to engage in cross-metathesis reactions with other alkenes, but this has not been apparently exploited so far. Here we show that this reactant enables the easy synthesis of tri- and tetra-susbtituted alkenes (i.e. isobutylenyl and prenyl groups) from simple alkenes under mild reaction conditions, not only with the conventional 2nd generation Grubbs catalyst but also with other Grela-ty...
Source: Chemistry - May 3, 2024 Category: Chemistry Authors: Paloma Mingueza Verdejo Silvia Rodr íguez Nuévalos Judit Oliver Meseguer Antonio Leyva-P érez Source Type: research
Controlling the Uptake and Release of Semiochemicals in Channel-type Metal-Organic Frameworks through Pore Expansion
Chemistry. 2024 May 3:e202401407. doi: 10.1002/chem.202401407. Online ahead of print.ABSTRACTSemiochemicals can be used to manipulate insect behaviour for sustainable pest management strategies, but their high volatility is a major issue for their practical implementation. Inclusion of these molecules within porous materials is a potential solution to this issue, as it can allow for a slower and more controlled release. In this work, we demonstrate that a series of Zr(IV) and Al(III) metal-organic frameworks (MOFs) with channel-type pores enable controlled release of three semiochemicals over 100 days by pore size design, ...
Source: Chemistry - May 3, 2024 Category: Chemistry Authors: Joshua Nicks Greig C Shearer Joseph Paul-Taylor James Lai-Morrice Chris Dadswell Daniel Guest William O H Hughes John Spencer Tina D üren Andrew David Burrows Source Type: research
New architecture based on Metal-Organic Frameworks and spin crossover complexes to detect volatile organic compounds
We present here the encapsulation of a spin crossover complex C1 [FeII(L)] (L: 4-amino-, 2-(2-pyridinylmethylene)hydrazide) inside MOF-808(Zr), a chemically robust Metal-Organic Framework. The compound C1⊂MOF-808 retains its crystallinity as well as a partial porosity compared to pristine MOF and shows solvatochromism under Volatile Organic compounds (VOCs) sorption associated to a spin state change of the guest complex. More specifically, this compound shows an interesting reversible color change under formaldehyde and formic acid vapor sorption and can therefore be considered as a new kind of optical VOCs chemosensor, ...
Source: Chemistry - May 3, 2024 Category: Chemistry Authors: Emmelyne Cuza Gilles Patriarche Christian Serre Antoine Tissot Source Type: research
Poly(2-oxazoline) Amphiphilicity Tunes the Excited-State Proton Transfer of Pyrenol-based Polyphotoacids
Chemistry. 2024 May 3:e202401047. doi: 10.1002/chem.202401047. Online ahead of print.ABSTRACTThe ability of light to change the properties of light-responsive polymers opens avenues for targeted release of cargo with a high degree of spatial and temporal control. Recently, we established photoacid polymers as light-switchable macromolecular amphiphiles. In these systems, light-induced excited-state proton transfer (ESPT) causes changes in amphilicity. However, as the intermolecular process itself critically depends on the local environment of the photoacid unit within the polymer, the overall amphiphilicity directly influe...
Source: Chemistry - May 3, 2024 Category: Chemistry Authors: Avinash Chettri Leonid Kaberov Niklas Klosterhalfen Sandunika Perera Mohammed Jamshied Felix Schacher Benjamin Dietzek-Ivansic Source Type: research
1,2,3-Triazole-containing azamacrocycles from chiral triazolopeptoids: synthesis and solid-state studies
Chemistry. 2024 May 3:e202400904. doi: 10.1002/chem.202400904. Online ahead of print.ABSTRACTTwo new chiral 1,2,3-triazole-containing macrocyclic oligoamides (i.e.: triazolopeptoid 4 and 5) were obtained through solid-phase synthesis of linear precursors followed by high dilution macrocyclization reaction. Theoretical (DFT) and spectroscopic (NMR) studies revealed the intricate interplay between the Na-chiral side chains and their conformational attitudes. BH3-mediated reduction of the tertiary amide groups of known 1-3 and newly synthesized 4 gave novel azamacrocycles 6-9. Detection of borane complexes of azamacrocycles 6...
Source: Chemistry - May 3, 2024 Category: Chemistry Authors: Alicja Araszczuk Giovanni Pierri Rosaria Schettini Chiara Costabile Giorgio Della Sala Luca Di Marino Consiglia Tedesco Francesco De Riccardis Irene Izzo Source Type: research
Chiral Induction in a Self-Assembled Pd4 Coordination Cage with Chiral Guests
In this study, we report the self-assembly of an achiral square-planar Pd(II) acceptor with a C2-symmetric tetrapyridyl donor resulted in the formation of a racemic mixture of the chiral octahedral cage Pd4L2. The existence of this racemic mixture was confirmed using circular dichroism spectroscopy as well as single crystal X-ray diffraction analysis. We encoded chiral information into the asymmetric cavity of the cage by encapsulating chiral aromatic guests through efficient π-π stacking and hydrophobic interactions in aqueous media. The inclusion of a chiral guest induces a preference for one enantiomeric conformation ...
Source: Chemistry - May 3, 2024 Category: Chemistry Authors: Raghunath Singha Pankaj Maity Dipak Samanta Source Type: research
Vibrational Circular Dichroism of a Chiral Triplet Nitrene Investigated under Matrix-Isolation Conditions in para-Hydrogen
Chemistry. 2024 May 3:e202401731. doi: 10.1002/chem.202401731. Online ahead of print.ABSTRACTVCD spectra of chiral high-spin organic radicals are expected to show a strong intensity enhancement and are thought to be difficult to predict using state-of-the-art theoretical methods. Herein we show that the chiral triplet nitrene obtained from photochemical cleavage of N2 from enantiopure 2-azido-9H-fluorenol does not feature extraordinarily strong intensities and that the experimental spectra match nicely with calculated ones. Thereby, this study demonstrates the general feasibility of studies on chiral high-spin organics by ...
Source: Chemistry - May 3, 2024 Category: Chemistry Authors: Frederike Beyer Corentin Grassin Julien F Rowen Wolfram Sander Christian Merten Source Type: research
Unspecific Peroxygenase (UPO) can be Tuned for Oxygenation or Halogenation Activity by Controlling the Reaction pH
Chemistry. 2024 May 3:e202401706. doi: 10.1002/chem.202401706. Online ahead of print.ABSTRACTUnspecific Peroxygenases (UPOs) are increasingly significant enzymes for selective oxygenations as they are stable, highly active and catalyze their reactions at the expense of only hydrogen peroxide as the oxidant. Their structural similarity to chloroperoxidase (CPO) means that UPOs can also catalyze halogenation reactions based upon the generation of hypohalous acids from halide and H2O2. Here we show that the halogenation and oxygenation modes of a UPO can be stimulated at different pH values. Using simple aromatic compounds su...
Source: Chemistry - May 3, 2024 Category: Chemistry Authors: Verity Barber Tamara Mielke Jared Cartwright Alba D íaz-Rodríguez William P Unsworth Gideon Grogan Source Type: research
Defect-Engineered Metal-Organic Framework/Polyimide Mixed Matrix Membrane for CO2 Separation
This study emphasizes that defect-engineered MOFs can be promising candidates for use as filler in the preparation of MMMs for the future development of membrane-based gas separation applications.PMID:38700479 | DOI:10.1002/chem.202401181 (Source: Chemistry)
Source: Chemistry - May 3, 2024 Category: Chemistry Authors: Samaneh Mashhadikhan Abtin Ebadi Mohamed Yasir Masoomi Hamidreza Sanaeepur Hermenegildo Garc ía Source Type: research
Stereoselective Synthesis of Polysubstituted Dihydropyrroles via 1,5-Addition and N-1,4-Addition Cascade
Chemistry. 2024 May 3:e202401350. doi: 10.1002/chem.202401350. Online ahead of print.ABSTRACTAn unprecedented 1,5-addition/N-1,4-addition cascade reaction is established via palladium hydride catalysis. A variety of polysubstituted dihydropyrrole skeletons are constructed in high yield and with exclusively >20:1 diastereoselectivity. An enantioselective protocol of this design is also developed to provide a novel access to enantioenriched dihydropyrroles.PMID:38700514 | DOI:10.1002/chem.202401350 (Source: Chemistry)
Source: Chemistry - May 3, 2024 Category: Chemistry Authors: Jing-Ming Zhang Yu-Chao Wang Liang Chen Chao Ma Zhi-Tao He Source Type: research
Carbohydrate-Functionalized Anthracene Carboximides as Multivalent Ligands and Bio-Imaging Agents
Chemistry. 2024 May 3:e202400941. doi: 10.1002/chem.202400941. Online ahead of print.ABSTRACTAnthracene carboximides (ACIs) conjugated with gluco-, galacto- and mannopyranosides are synthesized, by glycosylation of N-hydroxyethylanthracene carboximide acceptor with glycosyl donors. Glycoconjugation of anthracene carboximide increases the aq. solubility by more than 3-fold. The glycoconjugates display red-shifted absorption and emission, as compared to anthracene. Large Stokes shift (λabs/ λem = 445/525 nm) and high fluorescence quantum yields (Ф) of 0.86 and 0.5 occur in THF and water, respectively. The ACI-glycosides u...
Source: Chemistry - May 3, 2024 Category: Chemistry Authors: Anne George Narayanaswamy Jayaraman Source Type: research
Enhancing Control Over Nitric Oxide Photorelease via a Molecular Keypad Lock
Chemistry. 2024 May 3:e202400709. doi: 10.1002/chem.202400709. Online ahead of print.ABSTRACTBased on Boolean logic, molecular keypad locks secure molecular information, typically with an optical output. Here we investigate a rare example of a molecular keypad lock with a chemical output. To this end, the light-activated release of biologically important nitric oxide from a ruthenium complex is studied, using proton concentration and photon flux as inputs. In a pH-dependent equilibrium, a nitritoruthenium(II) complex is turned into a nitrosylruthenium(II) complex, which releases nitric oxide under irradiation with visible ...
Source: Chemistry - May 3, 2024 Category: Chemistry Authors: Hani M Elbeheiry Martin Schulz Source Type: research
Gaining Insights into the Interplay between Optical and Magnetic Properties in Photoexcited Coordination Compounds
We describe early and recent advances in the fascinating field of combined magnetic and optical properties of inorganic coordination compounds and in particular of 3d-4f single molecule magnets. We cover various applied techniques which allow for the correlation of results obtained in the frequency and time domain in order to highlight the specific properties of these compounds and the future challenges towards multidimensional spectroscopic tools. An important point is to understand the details of the interplay of magnetic and optical properties through performing time-resolved studies in the presence of external fields e...
Source: Chemistry - May 2, 2024 Category: Chemistry Authors: Jonas Braun Annie K Powell Andreas Neil Unterreiner Source Type: research
