Visible-light-induced Smiles rearrangement without release of SO 2 : rapid access to alkyl sulfonyl derivatives

Conventional visible-light-induced Smiles rearrangements generate C, N, or O radicals and release SO 2 . Herein, we describe a perfectly atom-economical protocol for Smiles rearrangements without release of SO 2 . 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.