Photocatalytic Perfluoroalkenylation of Ketones and Its Application in the Synthesis of Fluorinated Heterocycles.

A mild and efficient photocatalytic method for the α-perfluoroalkenylation of ketones via the corresponding enol silanes has been developed. Using a commercial ruthenium photocatalyst and DABCO under visible light irradiation, perfluoroenones were obtained in up to 89% yield and excellent Z-selectivity. The protocol is applicable to a broad range of (hetero)aromatic and aliphatic substrates. The resulting perfluoroenones serve as versatile intermediates for the synthesis of perfluorinated heterocycles such as pyrazoles, pyrimidines, or isoxazoles.