Copper-Mediated Synthesis of Substituted 2-Aryl-N-benzylbenzimidazoles and 2-Arylbenzoxazoles via C–H Functionalization/C–N/C–O Bond Formation
摘要:
An efficient method for the transformation of N-benzyl bisarylhydrazones and bisaryloxime ethers to functionalized 2-aryl-N-benzylbenzimidazoles and 2-arylbenzoxazoles is described. The protocol involves a copper(II)-mediated cascade C-H functionalization/C-N/C-O bond formation under neutral conditions. Substrates having either electron-donating or -withdrawing substituents undergo the cyclization to afford the target heterocycles at moderate temperature.
“All-water” one-pot diverse synthesis of 1,2-disubstituted benzimidazoles: hydrogen bond driven ‘synergistic electrophile–nucleophile dual activation’ by water
作者:Damodara N. Kommi、Pradeep S. Jadhavar、Dinesh Kumar、Asit K. Chakraborti
DOI:10.1039/c3gc37004f
日期:——
promoting the subsequent nitro reduction and in the final cyclocondensation steps. The role of water in promoting the cyclocondensation reaction through hydrogen bonds is realized by the differential product yields during the reaction of mono-N-phenyl-o-phenylenediamine with benzaldehyde performed separately in water and D2O. The better hydrogen bond donor and hydrogen bond acceptor abilities of water
One-pot strategy of copper-catalyzed synthesis of 1,2-disubstituted benzimidazoles
作者:Caixia Xie、Xushuang Han、Jian Gong、Danyang Li、Chen Ma
DOI:10.1039/c7ob00945c
日期:——
A simple, one-pot and copper-catalyzed coupling reaction for the construction of 1,2-disubstituted benzimidazole derivatives is described. Low-cost copper salt and weak base K3PO4 were utlized in this reaction. A variety of 1,2-disubstituted benzimidazoles were obtained in moderate to excellent yields.
An efficient method for the transformation of N-benzyl bisarylhydrazones and bisaryloxime ethers to functionalized 2-aryl-N-benzylbenzimidazoles and 2-arylbenzoxazoles is described. The protocol involves a copper(II)-mediated cascade C-H functionalization/C-N/C-O bond formation under neutral conditions. Substrates having either electron-donating or -withdrawing substituents undergo the cyclization to afford the target heterocycles at moderate temperature.