To a solution of N-(2-benzoyl-4-bromophenyl)-2,2,2-trifluoroacetamide (a) (0.37 g, 1.0 mmol) in degassed dry toluene (10 mL) was added a solution of tetrakis(triphenyl-phosphine) palladium [Pd(PPh3)4] in toluene (5 mL) under argon. The mixture was heated to reflux and tributyl(vinyl)tin (0.29 mL, Immol) was added in a dropwise fashion. After refluxing overnight, the mixture was cooled to room temperature and filtered. The filtrate was concentrated and the residue was purified by flash chromatography on silica gel [hexanes: ethyl acetate (9:1)] to give N-(2-benzoyl-4-vinylphenyl)-2,2,2-trifluoro-acetamide (b) (0.22 g, 70%). 1H NMR (300 MHz, CDCl3) δ 12.0 (s, 1H), 8.62 (d, J=10.9 Hz, 1H), 7.80-7.60 (m, 5H), 7.60-7.43 (m, 2H), 6.65 (dd, J=11, 19.6 Hz, 1H), 5.69 (d, J=19.6 Hz, 1H), 5.29 (d, J=11 Hz,1H). MS: 320.2 (M+H).
