COBALOXIME-CATALYZED HYDROPERFLUOROALKYLATION OF ELECTRON-DEFICIENT ALKENES WITH PERFLUOROALKYL HALIDES - REACTION AND MECHANISM

Direct hydroperfluoroalkylation of electron-deficient alkenes-ethyl acrylates 4, 7, and 8, acrylonitrile (5), and methyl vinyl ketone (6)-with perfluoroalkyl halides R(f)X (1, X = I;2, X = Br) in the presence of cobaloxime(III) (3) and zinc gives 1:1 hydroperfluoroalkylation adducts in good yields. This reaction provides a convenient synthesis of beta-(perfluoroalkyl)carboxylic esters 9, 12, and 13, nitriles 10, and ketones 11. Details of the reaction including effect of solvent, temperature, and ratio of reagents were examined. The reaction is proposed to proceed via a radical mechanism initiated by low-valent cobalt.