Synthesis of N -Aryl-4-trifluoromethylthiazol-2-amines via Insertion/Annulation of Trifluoromethylimidoyl Sulfoxonium Ylides with Sodium Thiocyanate.

An efficient p -TsOH-mediated insertion of sodium thiocyanate into trifluoromethylimidoyl sulfoxonium ylides has been reported, affording annulated N -aryl-4-trifluoromethylthiazol-2-amines in 42-84% yields in a one-pot manner. This protocol encompasses a variety of trifluoromethylimidoyl sulfoxonium ylides with thiocyanate serving as the source of the "S-C═N" moiety of the thiazole ring. The versatile transformations of the resulting pharmacologically important N -aryl-4-trifluoromethylthiazol-2-amines were also demonstrated.