Push-pull alkenes by reacting N,N′-dimethyl cyclic ketene N,N′-acetals with isocyanates: synthesis, structures, and reactivities

N,N′-Dimethyl cyclic ketene N,N′-acetals react with two or three equivalents of isocyanates to generate tetrasubstituted push-pull alkene derivatives in one-pot sequential reactions. X-ray crystallography showed significant elongations and out of plane distorsions of the polarized carbon-carbon double bonds.