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941.
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944.
Saidbakhrom Saidjalolov Dr. Zainab Edoo Dr. Matthieu Fonvielle Louis Mayer Dr. Laura Iannazzo Dr. Michel Arthur Prof. Dr. Mélanie Etheve-Quelquejeu Dr. Emmanuelle Braud 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(10):3542-3551
The carbapenem class of β-lactams has been optimized against Gram-negative bacteria producing extended-spectrum β-lactamases by introducing substituents at position C2. Carbapenems are currently investigated for the treatment of tuberculosis as these drugs are potent covalent inhibitors of l,d -transpeptidases involved in mycobacterial cell wall assembly. The optimization of carbapenems for inactivation of these unusual targets is sought herein by exploiting the nucleophilicity of the C8 hydroxyl group to introduce chemical diversity. As β-lactams are structure analogs of peptidoglycan precursors, the substituents were chosen to increase similarity between the drug and the substrate. Fourteen peptido-carbapenems were efficiently synthesized. They were more effective than the reference drug, meropenem, owing to the positive impact of a phenethylthio substituent introduced at position C2 but the peptidomimetics added at position C8 did not further improve the activity. Thus, position C8 can be modified to modulate the pharmacokinetic properties of highly efficient carbapenems. 相似文献
945.
Dr. Xavier Just-Baringo Alejandro Yeste-Vázquez Javier Moreno-Morales Dr. Clara Ballesté-Delpierre Prof. Jordi Vila Prof. Ernest Giralt 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(51):12987-12991
The introduction of a novel tetra-ortho-chloroazobenzene amino acid (CEBA) has enabled photoswitching of the antimicrobial activity of tyrocidine A analogues by using exclusively visible light, granting spatiotemporal control under benign conditions. Compounds bearing this photoswitchable amino acid become active upon irradiation with red light, but quickly turn-off upon exposure to other visible light wavelengths. Critically, sunlight quickly triggers isomerisation of the red light-activated compounds into their original trans form, offering an ideal platform for self-deactivation upon release into the environment. Linear analogues of tyrocidine A were found to provide the best photocontrol of their antimicrobial activity, leading to compounds active against Acinetobacter baumannii upon isomerisation. Exploration of their N- and C-termini has provided insights into key elements of their structure and has allowed obtaining new antimicrobials displaying excellent strain selectivity and photocontrol. 相似文献
946.
947.
Dimerization of Colloidal Particles through Controlled Aggregation for Enhanced Properties and Applications
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Devising syntheses capable of precisely manipulating matter on the nanoscale is central to many areas of research. The underlying motivation is fueled by the fact that at the nanometer scale, the property has a strong correlation with the structure. One such nanostructure that has accrued much attention is the dimer—a structure composed of two colloidal particles separated by a small gap. This Focus Review discusses how colloidal stability can be strategically manipulated to induce dimerization, together with effective purification steps to further improve yields. We conclude the article by providing representative examples for how dimers composed of plasmonic nanoparticles leads to structures with tunable optical properties and strong electric near‐fields, ideal for application in surface‐enhanced Raman spectroscopy. 相似文献
948.
Inside Cover: High‐Nuclear Organometallic Copper(I)–Alkynide Clusters: Thermochromic Near‐Infrared Luminescence and Solution Stability (Chem. Eur. J. 49/2016)
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949.
Dr. Xisen Hou Prof. Chenfeng Ke Dr. Yu Zhou Dr. Zhuang Xie Dr. Ahmed Alngadh Dr. Denis T. Keane Dr. Majed S. Nassar Dr. Youssry Y. Botros Prof. Chad A. Mirkin Prof. J. Fraser Stoddart 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(35):12301-12306
Covalent and supramolecular polymerizations, both of which offer their own unique advantages, have emerged as popular strategies for making artificial materials. Herein, we describe a concurrent covalent and supramolecular polymerization strategy—namely, one which utilizes 1) a bis‐azide‐functionalized diazaperopyrenium dication that undergoes polymeriation covalently with a bis‐alkyne‐functionalized biphenyl derivative in one dimension as a result of a rapid and efficient β‐cyclodextrin(CD)‐accelerated, cucurbit[6]uril(CB)‐templated azide–alkyne cycloaddition, while 2) the aromatic core of the dication is able to dimerize in a criss‐cross fashion by dint of π–π interactions, enabling simultaneous supramolecular assembly, resulting in an extended polymer network in an orthogonal dimension. 相似文献
950.
A Facile Approach to Optically Active Hydroquinoline‐2‐carboxylates by a One‐Pot Asymmetric Michael/Transamination/Cyclization Process
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Dr. Chao Rong Hongjie Pan Dr. Mao Liu Hua Tian Dr. Yian Shi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(9):2887-2891
An efficient one‐pot synthesis of optically active hydroquinoline‐2‐carboxylates from 1,3‐cyclohexanediones, β,γ‐unsaturated α‐keto ester, and benzylamine in the presence of a chiral base catalyst and 1,8‐diazabicyclo[5.4.0]undec‐7‐ene (DBU) with good diastereoselectivity and high enantioselectivity is described. The reaction proceeds by a sequential asymmetric Michael/transamination/cyclization process. 相似文献