Trifluoromethylation of α-Haloketones

The C-X bond (X = Br, Cl) of alpha-haloketones is smoothly trifluoromethylated with the fluoroform-derived CuCF3 reagent recently developed in our laboratories. This is the first nucleophilic alpha-trifluoromethylation reaction of carbonyl compounds and a rare example of CF3-C(sp(3)) coupling. The transformation employs only low-cost chemicals and cleanly occurs in up to 99% yield at room temperature, thereby providing an unprecedentedly easy entry to valuable 2,2,2-trifluoroethylketones.