Copper-Catalyzed Intramolecular Carbocyclization/1,2-Migration Reaction of Allenols To Access Substituted 2-Sulfonyl Carbazoles

A copper-catalyzed intramolecular cascade carbocyclization/1,2-migration of C-2 indolyl-allenol has been achieved to construct the library of 2-sulfonyl carbazoles, which possess considerable biological significance. This modular protocol is operationally simple, exhibiting a broad substrate scope with consistently high yields. Additionally, gram-scale synthesis, product diversification of 2-sulfonyl carbazoles, and DFT studies of the catalytic cycle have been performed. Overall, this study unfolds a new strategy for the one-pot synthesis of sulfonyl carbazoles, which holds significance in medicinal and material chemistry.