Rh(III)‐Catalyzed Regioselective [3 + 2]‐Annulation of Indoles with 1,3‐Enynes to Access 3H‐pyrrolo[1,2‐a]indol‐3‐ones

Abstract: Herein, we present a novel and highly efficient strategy for the synthesis of synthetically valuable 3H‐pyrrolo[1,2‐a]indol‐3‐ones via a Rh(III)‐catalyzed regioselective [3 + 2] annulation strategy. The protocol ensures precise regioselective insertion of substituted 1,3‐enynes at the less sterically hindered site, while offering a broad substrate scope, excellent functional group compatibility, and mild reaction conditions. Moreover, the methodology is amenable to gram‐scale synthesis and demonstrates the successful application of terbinafine as a substrate within this transformation.