Convenient preparation of 4-arylmethyl- and 4-hetarylmethyl thiazoles by regioselective cycloaddition reactions of 3-sulfanyl- and selanylpropargyl alcohols

Complete details of thiazole syntheses by scandium-catalyzed cycloaddition reactions of 1-aryl- and 1,1-bisaryl-3-phenylsulfanylpropargyl alcohols with thioamides are described. Reactions of 1,1-bisarylpropargyl alcohols with thioamides and selenamide in MeNO2/H2O resulted in 4-bisarylmethyl-1,3-thiazoles 4aa–ic and 4H-4,4-bisaryl-1,3-thiazines 5ea–ga in high yields. Reactions in MeNO2/D2O resulted in 4-bisaryldeuteriomethyl-1,3-thiazoles 10ca–ia with high deuterium purity. Reactions of dialkyl and alkyl aryl propargyl alcohols are also described.