Construction 7-membered ring via Ni–Al bimetal-enabled C–H cyclization for synthesis of tricyclic imidazoles

Abstract

Transition metal-catalyzed C−H cyclization for medium-ring synthesis has been limited to reactive C−H bonds, the activation of unreactive C−H bonds still remains a challenge. Here the authors show the direct construction of 7-membered rings via Ni−Al co-catalyzed unreactive C−H cyclization of benzoimidazoles with alkenes, providing a series of tricyclic imidazoles.