Trifluoromethylation of α‑Haloketones

The C–X bond (X = Br, Cl) of α-haloketones is smoothly trifluoromethylated with the fluoroform-derived CuCF₃ reagent recently developed in our laboratories. This is the first nucleophilic α-trifluoromethylation reaction of carbonyl compounds and a rare example of CF₃–C­(sp³) 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