Copper-catalyzed radical 1,2-cyclization of indoles with arylsulfonyl hydrazides: access to 2-thiolated 3H-pyrrolo[1,2-a]indoles

A copper-catalyzed cascade radical 1,2-cyclization of indoles with arylsulfonyl hydrazides was developed, affording a series of 2-thiolated 3H-pyrrolo[1,2-a]indoles in moderate to excellent yields. This transformation proceeded with sequential radical addition to a triple bond and a cyclization procedure, where arylsulfonyl hydrazides served as thioarylation reagents.