Sulfonamide as Photoinduced Hydrogen-Atom Transfer Catalyst for Regioselective Alkylation of C(sp3)–H Bonds Adjacent to Heteroatoms

Based on the DFT calculations, the sulfonamide was explored as an efficient hydrogen-atom transfer catalyst for the C(sp3)–H alkylation. The combination of a metal-free photoredox catalyst and a sulfonamide catalyst enables highly regioselective alkylation of the C–H bonds adjacent to heteroatoms, which features broad substrate scope and excellent functional group compatibility. Remarkably, the sulfonamide catalyst was also applicable to the C(sp3)–C(sp3) couplings through the merger of photoredox, nickel, and HAT catalysis.