Visible-Light-Mediated α-Ketoacylations of N H-Sulfoximines with gem -Difluoroalkenes.

A photochemical approach for the preparation of α-keto- N -acyl sulfoximines from N H sulfoximines and gem -difluoroalkenes has been developed. In the presence of NBS, the reactions proceed in air without the need of a photocatalyst or additional oxidant. Results of mechanistic studies suggest that the two oxygens in the products stem from water and dioxygen.