Catalytic C–H α‑Trifluoromethylation of α,β-Unsaturated Carbonyl Compounds

A copper(I)-catalyzed, regioselective C–H α-trifluoromethylation of α,β-unsaturated carbonyl compounds using Togni’s reagent was developed. Diverse substrates, including enones as well as α,β-unsaturated esters, thioesters, and amides, stereospecifically afforded the corresponding (E)-α-trifluoromethylated products in moderate to high yields. Further, this method was applied to the C–H trifluoromethylation of drugs.