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 organophotoredox conditions, aryl diazonium salts reacts with readily available SO 2 source (DABSO) to afford the desired product via simple nucleophilic fluorination. The reaction scope tolerates the presence of both electron-rich and -poor aryls and demonstrated a broad functional group tolerance. To shed the light on the reaction mechanism, several experimental techniques have been combined including fluorescence, NMR, EPR spectroscopy as well as DFT calculations.