Photocatalytic Generation of 2-Azolyl Radicals: Intermediates for the Azolylation of Arenes and Heteroarenes via C–H Functionalization
作者:Amandeep Arora、Jimmie D. Weaver
DOI:10.1021/acs.orglett.6b01718
日期:2016.8.19
2-bromoazoles via photocatalysis, is a powerful intermediate for the intermolecular arylation of unmodified (hetero)arenes. The reaction is characterized by mild conditions, operational simplicity, tolerance toward functional and sterically demanding groups, broad scope, and anti-Minisci selectivity. A working mechanism is provided, and a low-solubility amine is essential for successful coupling. The utility
Cobalt-Catalyzed Decarboxylative C–H (Hetero)Arylation for the Synthesis of Arylheteroarenes and Unsymmetrical Biheteroaryls
作者:Yanrong Li、Fen Qian、Mengshi Wang、Hongjian Lu、Guigen Li
DOI:10.1021/acs.orglett.7b02730
日期:2017.10.20
benzothiazoles or benzoxazoles is reported. This represents a first example of metal-catalyzed decarboxylative C–H heteroarylation of benzo-fused heterocycles. The transformation provides a convenientroute, with good yields and functional group tolerance, to various important arylheteroaryl and unsymmetrical biheteroaryl structural motifs.
<i>t</i>-BuONa-mediated direct C–H halogenation of electron-deficient (hetero)arenes
作者:Xia Liu、Xin Zhao、Fushun Liang、Baoyi Ren
DOI:10.1039/c7ob03081a
日期:——
An efficient halogenation of electron-deficient (hetero)arenes is described. The reaction utilizes common t-BuONa as a catalyst (for iodination) or a promoter (for bromination and chlorination), and perfluorobutyl iodide, CBr4 or CCl4 as the readily-available halogenating agents, respectively. The protocol features broad scope, high efficiency, mild conditions and gramscalability. An ionic pathway
Pyridinium chlorochromate (PCC) supported on silica gel effects the oxidative cyclization of structurally diverse thiophenolic and phenolic Schiff's bases, thereby providing an efficient and convenient method for the synthesis of a library of 2-arylbenzothiazoles and 2-arylbenzoxazoles.
Microwave-assisted one-pot synthesis of benzothiazole and benzoxazole libraries as analgesic agents
作者:C PRAVEEN、A NANDAKUMAR、P DHEENKUMAR、D MURALIDHARAN、P T PERUMAL
DOI:10.1007/s12039-012-0251-3
日期:2012.5
Microwave-assisted synthesis of benzothiazole and benzoxazole libraries via PIFA promoted cyclocondensation of 2-aminothiophenols/2-aminophenols with aldehydes under one-pot condition in good to excellent yields was achieved. Twenty compounds have been investigated for their analgesic activity and showed moderate to good activity.