Synthesis of benzimidazoles by Cu2O-catalyzed cascade reactions between o-haloaniline and amidine hydrochlorides

An efficient Cu2O-catalyzed method for the synthesis of benzimidazole derivatives from amidine hydrochlorides and o-haloaniline has been developed. The cascade C–N coupling and intramolecular transamination reaction provided benzimidazole derivatives in high yields up to 90%.