Metal?Free Visible?Light Synthesis of Arylsulfonyl Fluorides: Scope and Mechanism

The first metal-free procedure for the synthesis of arylsulfonyl fluorides is reported. Under organo-photoredox conditions, aryl diazonium salts react with a readily available SO2 source (DABSO) to afford desired product through simple nucleophilic fluorination. reaction tolerates presence both electron-rich and -poor aryls demonstrated broad functional group tolerance. To shed light on mechanism, several experimental techniques were combined, including fluorescence, NMR, EPR spectroscopy as well DFT calculations.