Regioselective Rh(III)-Catalyzed Spiro-Cyclization and ortho-C(sp2)–H-Annulations of Secondary Aromatic Amide with Maleimide: Construction of Spiropyrrolidinetriones and Dibenzoazocinetriones

Abstract

A facile Rh(III)-catalyzed spiro-cyclization and ortho-(proximal) aromatic C–H activation reaction of amides with maleimides has been established via a weakly coordinating amide carbonyl acting as the directing group. This protocol features high competence, functional group tolerance, and wide-ranging substrate scope and, by slight adjustments of the reaction conditions, affords either a variety of spiropyrrolidinetrione or substituted 8-membered unsaturated lactams known as azocines in moderate yields. Additionally, the reaction is highly regioselective, furnishing mono-ortho-spiro and mono-ortho-8-membered annulated products.