Rhodium(III)‐Catalyzed [3+2] Annulation of 5‐Aryl‐2,3‐dihydro‐1 H ‐pyrroles with Internal Alkynes through C(sp 2 )H/Alkene Functionalization

This study describes a new rhodium(III)‐catalyzed [3+2] annulation of 5‐aryl‐2,3‐dihydro‐1H‐pyrroles with internal alkynes using a Cu(OAc) 2 oxidant for building a spirocyclic ring system, which includes the functionalization of an aryl C(sp 2 )H bond and addition/protonolysis of an alkene CC bond. This method is applicable to a wide range of 5‐aryl‐2,3‐dihydro‐1H‐pyrroles and internal alkynes, and results in the assembly of the spiro[indene‐1,2′‐pyrrolidine] architectures in good yields with excellent regioselectivities.