Rhodium-catalyzed novel trifluoromethylation at the α-position of α-β-unsaturated ketones

Treatment of alpha,beta-unsaturated ketones with CF3I in the presence of Et2Zn and RhCl(PPh3)(3) gave novel alpha-trifluoromethylation products in good yields. Hydrogen transfer from the ethyl group on the rhodium complex to the beta-position of the enone seems to play an important role in this reaction.