Chemoselective Lactam Formation in the Addition of Benzenesulfonyl Bromide to N-Allyl Acrylamides and N-Allyl 3,3-Dimethylacrylamides

Chemoselectivity in the addition and cyclization reactions of PhSO 2 Br to N -allyl acrylamides has been confirmed due to the higher reactivity of the acrylic C C bond toward the sulfonyl radical than that of the allyl C C bond. Formation of γ-lactams by C β →C α cyclization can be achieved with N -allyl 3,3-dimethylacrylamides.