Enantioselective α-Trifluoromethylthiolation of Carbonyl Compounds with AgSCF 3 and Trichloroisocyanuric Acid.

We successfully developed an enantioselective trifluoromethylthiolation of structurally diverse carbonyl compounds. Trichloroisocyanuric acid and AgSCF 3 were employed to generate active electrophilic trifluoromethylthio species in situ for asymmetric C-SCF 3 bond formation. A broad variety of chiral SCF 3 -carbon nucleophiles (pyrazolones, β-keto esters, and β-keto amides) were obtained in excellent yields with high enantioselectivities (up to 92% ee) by Cinchona alkaloid derived squaramide catalysts. The reaction exhibits high efficiency, good enantioselectivity, and high functional group tolerance, which provided a novel and efficient way for asymmetric synthesis of trifluoromethylthiolated carbonyl compounds.