Visible-Light-Mediated Divergent Difunctionalization of gem-Difluoroalkenes Using Aryldiazonium Tetrafluoroborates

Functionalization of fluoro synthons is an efficient way to construct highly functionalized organofluorine compounds. However, the direct synthesis of α,α-difluoromethyl sulfones from readily accessible gem-difluoroalkenes remains underexplored. This study reports a photocatalytic strategy for the divergent difunctionalization of gem-difluoroalkenes, employing sodium metabisulfite and aryldiazonium tetrafluoroborates. A series of β-hydroxy, β-alkoxy, and β-formyloxy sulfones was obtained in moderate to excellent yields. Furthermore, β-hydroxy and β-alkoxy trichloromethyl compounds can also be synthesized using chloroform as the solvent.