Rhodium/Copper‐Catalyzed Annulation of Benzimides with Internal Alkynes: Indenone Synthesis through Sequential CH and CN Cleavage

Doubled up: A rhodium(III)/copper(II) system co-catalyzes the annulation of benzimides with internal alkynes for the synthesis of indenones (see scheme; Cp*=C5Me5). The reaction involves an uncommon nucleophilic addition of a transition-metal–carbon bond to an imide moiety. This novel reaction provides a facile route to synthesize indenones from readily available benzimides and internal alkynes.