Copper-catalyzed domino intramolecular cyclization: a facile and efficient approach to polycyclic indole derivatives

Abstract

A mild and efficient Cu₂O-catalyzed domino intramolecular C–N coupling/C–Y (Y = O, S, N) bond formation was successfully achieved. Thus oxazino[3,2-a]indole, thiazino[3,2-a]indole and indolo[2,1-b]quinazoline derivatives were facilely assembled from readily accessible gem-dibromovinyl systems. The protocol is general and practical, affording a variety of the indole-incorporated products in good to excellent yields even under air atmosphere.