Site-Selective C-H Sulfinamidation through Electron-Donor-Acceptor Complex Photoactivation and Radical Addition into Sulfinylamine Reagents.

Aryl sulfinamides are versatile synthetic intermediates for accessing diverse and medicinally relevant S(VI) functionalities, such as sulfonamides and sulfonimidamides. Herein, we report a thianthrenium-enabled, site-selective C-H sulfinamidation procedure via a blue-light-promoted electron-donor-acceptor (EDA) complex to afford the key aryl sulfinamide species. This operationally simple procedure combines site-selective C-H sulfonium salt preparation followed by single-electron transfer (SET) from a photoactive EDA complex formed with readily available amines. The resultant aryl radicals react with sulfinylamine reagents to deliver aryl sulfinamides under mild conditions. The method displays broad generality and regioselectively constructs key aryl sulfinamides from medicinally relevant arenes without using expensive transition metal or photoredox catalysts, highlighting its use as a late-stage functionalization tool for medicinal and drug discovery chemistry.