Copper-catalyzed regioselective cyclization of vinyl azides by gem-difluoromethylene for trisubstituted pyridines

Abstract

A novel copper-catalyzed cyclization of readily available vinyl azides with gem-difluoromethylene is described. This protocol is highly efficient and regioselective for assembling diverse trisubstituted pyridines in good to excellent yields, in which gem-difluoromethylene acted as a C1 precursor with a carbonyl group via triple cleavage and vinyl azides played a pivotal dual role.