Visible-Light-Promoted Redox Neutral γ,γ-Difluoroallylation of Cycloketone Oxime Ethers with Trifluoromethyl Alkenes via C-C and C-F Bond Cleavage

A visible-light-promoted redox neutral gamma,gamma-difluoroallylation of cycloketone oxime ethers with trifluor-omethyl alkenes through C-C and C-F bond cleavage has been achieved, which affords various cyano-substituted gem-difluoroalkenes in generally good yields. The reaction provides a facile protocol for forming gem-difluoroalkene functionality and a cyano group while incorporating them into one molecule. The conversion of the resulting cyano-substituted gem-difluoroalkenes to cyclic monofluoroalkenes via a second C-F bond cleavage was also described.