Rh(iii)-catalyzed [4 + 1] cyclization of aryl substituted pyrazoles with cyclopropanols via C–H activation

Abstract

A rhodium-catalyzed formal [4 + 1]-cyclization reaction of aryl substituted pyrazoles with cyclopropanols via C–H bond activation/cyclization processes to selectively construct a series of carbonyl functionalized pyrazolo[5,1-a]isoindoles is described. The reaction features good functional group compatibility and a broad substrate scope with respect to both cyclization components with up to 84% yields. Mechanistic studies indicated that the C–H cleavage might be the rate-determining step in this transformation.