Synthesis of 3-Iminoacrylic Esters by Horner–Wadsworth–Emmons Reactions of Isocyanates Using Potassium Hexamethyldisilazide

Ethyl 2-methyl-3-(phenylimino)acrylate containing a ketenimine structure was synthesized by Horner–Wadsworth–Emmons reaction of ethyl 2-(diethylphosphono)propionate and phenyl isocyanate using potassium hexamethyldisilazide. Synthesis of several 3-iminoacrylic esters and their analogues, all belonging to the class of conjugated ketenimines, was also achieved.