Iron-Catalyzed Ligand-to-Metal Charge Transfer (LMCT) Desulfonylation of Sulfonamides under Visible Light.

Mild desulfonylation of sulfonamides remains an important transformation in synthetic chemistry. Herein, we report an iron photocatalytic platform based on ligand-to-metal charge transfer (LMCT) for visible-light-induced desulfonylation of sulfonamides. Using a simple Fe(OTs)3/TBAOx system, a variety of heteroaryl, diarylamine, and amide-derived sulfonamides underwent efficient N-S bond cleavage without stoichiometric metal reductants. The method exhibits broad functional-group tolerance and enables rapid deprotection of an AZD4604 intermediate within 2 h.