Organic semiconductor photocatalyst can bifunctionalize arenes and heteroarenes
作者:Indrajit Ghosh、Jagadish Khamrai、Aleksandr Savateev、Nikita Shlapakov、Markus Antonietti、Burkhard König
DOI:10.1126/science.aaw3254
日期:2019.7.26
Two-for-one approach to photoredox In photoredox catalysis, an excited chromophore typically activates a single reactant either by oxidizing or reducing it. Ghosh et al. used a semiconductor catalyst to activate two reactants at once by quenching both an excited electron and the residual positive hole (see the Perspective by Swift). As such, two different reactive carbon or halide fragments could be
光氧化还原二合一方法 在光氧化还原催化中,激发的发色团通常通过氧化或还原单个反应物来激活它。戈什等人。使用半导体催化剂通过淬灭激发的电子和残留的空穴来同时激活两种反应物(参见 Swift 的观点)。因此,可以将两个不同的反应性碳或卤化物片段附加到芳环上的不同位点。该催化剂还可以耐受氰化物等强亲核试剂,并且可以轻松回收和重复使用。科学,这个问题 p。360; 另见第。320 半导体光催化剂上氧化和还原位点的形成促进了双自由基加成反应。半导体表面上的光激发电子-空穴对可以与两种不同的基材进行氧化还原反应。与传统的电合成类似,主要的氧化还原中间体仅提供单独的氧化和还原产物,或者更罕见地结合成一种加成产物。在这里,我们报告了一种稳定的有机半导体材料,介孔石墨碳氮化物 (mpg-CN),可以充当可见光光氧化还原催化剂,以协调氧化和还原界面电子转移到两个或三个组件中的两种不同基材。用于芳烃和杂芳烃的直接双重碳氢功能化的系统。mpg-CN
Generation of Aryl and Heteroaryl Magnesium Reagents in Toluene by Br/Mg or Cl/Mg Exchange
作者:Dorothée S. Ziegler、Konstantin Karaghiosoff、Paul Knochel
DOI:10.1002/anie.201802123
日期:2018.5.28
very fast Br/Mgexchange with aryl and heteroaryl bromides, producing aryl and heteroaryl magnesium alkoxides (ArMgOR⋅LiOR) in toluene. These Grignard reagents react with a broad range of electrophiles, including aldehydes, ketones, allyl bromides, acyl chlorides, epoxides, and aziridines, in good yields. Remarkably, the related reagent sBu2Mg⋅2 LiOR (R=2‐ethylhexyl) undergoes Cl/Mgexchange with various
Discovery of 2,4-dimethoxypyridines as novel autophagy inhibitors
作者:Lucas Robke、Tiago Rodrigues、Peter Schröder、Daniel J. Foley、Gonçalo J.L. Bernardes、Luca Laraia、Herbert Waldmann
DOI:10.1016/j.tet.2018.07.021
日期:2018.8
modulators of autophagy are in great demand. Herein, we describe a phenotypic high-content screen for autophagy inhibitors, which led to the discovery of a dimethoxypyridine-based class of autophagy inhibitors, which derive from previously reported, natural product-inspired MAP4K4 inhibitors. Comprehensive structure-activity relationship studies led to a potent compound, and biological validation experiments
Large-Scale Preparation of Aromatic Fluorides via Electrophilic Fluorination with Functionalized Aryl- or Heteroarylmagnesium Reagents
作者:Paul Knochel、Shigeyuki Yamada
DOI:10.1055/s-0029-1218816
日期:2010.7
Functionalized aryl- or heteroarylmagnesium reagents, prepared from the corresponding bromides or iodides using halogen-magnesium exchange or direct magnesium insertion in the presence of lithiumchloride, reacted smoothly with N-fluorobenzenesulfonimide, (PhSO2)2NF, in the mixedsolvent (4:1 CH2Cl2-perfluorodecalin) to give the corresponding aromatic fluorides in moderate to good yields. arenes - electrophilic
Give me an “F”: Electrophilic fluorination of various aromatic and heteroaromatic Grignardreagents is smoothly performed with (PhSO2)2NF as fluorinating agent in a 4:1 mixture of CH2Cl2/perfluorodecalin (see scheme). This solvent system allows minimization of most side reactions.