K ₂ S ₂ O ₈ -Mediated Bromination/Truce–Smiles Rearrangement/Desulfonylation of N -Arylsulfonyl Acrylamides: Access to β-Brominated Amide Derivatives

-brominated amides containing a quaternary carbon center in good yields. Mechanistic studies indicated that the formation of bromine radicals represents the crucial step in this radical cascade transformation. This approach provides a complementary and efficient route toward the synthesis of valuable β-brominated amide derivatives.