Enantioselective Synthesis of Benzothiazolines from Fluoroalkyl Ketones Using Chiral Imidazoline−Phosphoric Acid Catalysts

The first enantioselective synthesis of cyclic N,S‐ketals having tetrasubstituted chiral center through intramolecular cyclization between carbonyl compounds and aminothiols has been developed. The reaction of fluoroalkyl ketones with aminobenzenethiols using a chiral imidazoline−phosphoric acid catalyst afforded products in high yields with high enantioselectivity. The observed enantioselectivity is explained using preliminary mechanistic information.