Enantioselective Vinylogous Mannich-Type Reactions to Construct CF₃S-Containing Stereocenters Catalysed by Chiral Quaternary Phosphonium Salts

A series of benzyl trifluoromethyl sulphides bearing a nitro group were utilized as CF3S-containing building blocks to construct chiral CF3S-containing molecules via enantioselective vinylogous Mannich-type reactions. In such reactions, high yields and enantioselectivities were obtained using chiral quaternary phosphonium salts derived from amino acids. Moreover, a chiral cyclic urea bearing the CF3S moiety was obtained from further transformation of the product.