Preparation of 1,2-substituted benzimidazoles via a copper-catalyzed three component coupling reaction

1,2-Substituted benzimidazoles were prepared by simply stirring a mixture of copper catalysts, N-substituted o-phenylenediamines, sulfonyl azides and terminal alkynes. Particularly, the intermediate N-sulfonylketenimine occurred with two nucleophilic addition and the sulfonyl group was eliminated via cyclization. In a way, sulfonyl azides and copper catalysts activated the terminal alkynes to synthesize benzimidazoles.

Automated summary

1,2-Substituted benzimidazoles were synthesized by stirring a mixture of copper catalysts, N-substituted o-phenylenediamines, sulfonyl azides, and terminal alkynes. The intermediate N-sulfonylketenimine underwent two nucleophilic additions and elimination of the sulfonyl group via cyclization, with sulfonyl azides and copper catalysts activating the terminal alkynes for benzimidazole synthesis.