Acid mediated synthesis of thiazolines, thiazoles and enamide derivatives from methyl enol ethers: Application towards synthesis of wilsoniamine B

An efficient metal-free synthesis of thiazolines, dihydrothiazole and enureas or thioureas from methyl enol ether with urea or thiourea derivatives in the presence of TFA (trifluoroacetic acid) are reported here. This synthetic protocol involves the formation of two bonds, C–N as well as C–S, in one step for the synthesis of thiazoline derivatives, dihydrothiazoles and a direct C–N bond for the synthesis of enamides with good to excellent yields. Further, this method was employed for the synthesis of wilsoniamine B alkaloid.