Rhodium(III)-Catalyzed [3+2] Annulation of 5-Aryl-2,3-dihydro-1H-pyrroles with Internal Alkynes through C(sp2)-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.