Conventional visible-light-induced Smiles rearrangements generate C, N, or O radicals and release SO2. Herein, we describe a perfectly atom-economical protocol for Smiles rearrangements without release of SO2. The protocol not only afforded alkyl sulfinic acid salts via photocatalyzed radical addition, aryl migration, and sulfone radical reduction but also permitted efficient functionalization of butenyl heteroaryl sulfone derivatives under mild conditions.
