Lewis base-catalyzed cascade [4 + 2]-annulation reaction of N-alkoxy acrylamides and acyl isothiocyanates: facile access to 2-imino-1,3-thiazinone derivatives

A Lewis base-catalyzed cascade aza-nucleophilic addition/thio-Michael addition reaction of N -alkoxy acrylamides with acyl isothiocyanates has been developed to afford various 2-imino-1,3-thiazinone derivatives in 40–97% yields.