The synthesis of substituted benzimidazoles, 2-aminobenzimidazoles, 2-aminobenzothiazoles, and benzoxazoles is described via intramolecularcyclization of o-bromoaryl derivatives using copper(II) oxide nanoparticles in DMSO under air. The procedure is experimentally simple, general, efficient, and free from addition of external chelating ligands. It is a heterogeneous process and the copper(II) oxide
Cobalt(II)-complex catalyzes efficiently the intramolecular C–N and C–O cross-couplings of Z-N′-(2-halophenyl)-N-phenylamidines and N-(2-bromophenyl)benzamides to afford the corresponding substituted benzimidazoles and benzoxazoles in the presence of K2CO3 at moderate temperature. The protocol is general, air stable and affords the products selectively in moderate to high yield.
钴(II)配合物有效催化Z - N '-(2-卤代苯基)-N-苯基am和N-(2-溴苯基)苯甲酰胺的分子内C – N和C – O交叉偶联,提供相应的取代苯并咪唑在中等温度下在K 2 CO 3存在下使用苯并恶唑和苯并恶唑。该方案是一般的,空气稳定的,并且以中等至高收率选择性地提供产物。
An Improved Procedure for the Synthesis of Benzimidazoles, Using Palladium-Catalyzed Aryl-Amination Chemistry
作者:Christopher T. Brain、James T. Steer
DOI:10.1021/jo034824l
日期:2003.8.1
New, improved conditions have been developed and optimized for the synthesis of benzimidazoles by intramolecular palladium-catalyzed aryl-amination chemistry. This methodology, combined with a "catch and release" purification strategy, has led to a range of these heterocycles being prepared rapidly and in excellent yield.
Transition-Metal-Free Synthesis of Benzimidazoles Mediated by KOH/DMSO
作者:Hannah Baars、Astrid Beyer、Stefanie V. Kohlhepp、Carsten Bolm
DOI:10.1021/ol403414v
日期:2014.1.17
Benzimidazoles are prepared by intramolecular N-arylations of amidines mediated by potassium hydroxide in DMSO at 120 degrees C. In this manner, diversely substituted products have been obtained in moderate to very good yields.
An intramolecular palladium-catalysed aryl amination reaction to produce benzimidazoles
作者:Christopher T Brain、Shirley A Brunton
DOI:10.1016/s0040-4039(02)00132-6
日期:2002.3
A novel synthesis of benzimidazoles by a palladium-catalysed intramolecular N-arylation reaction from (o-bromophenyl)amidine precursors is described. (C) 2002 Elsevier Science Ltd. All rights reserved.