4-Substituted imidazolidin-2-ones were synthesized via the one-pot reaction of bench-stable α-chloroaldoxime O-methanesulfonates and 4-aminobut-2-enoates in the presence of N,N-dimethylaminopyridine. This cascade transformation involved nucleophilic substitution, Tiemann rearrangement and intramolecular Michael addition. The electronic effect of the aryl substituent of the chloroaldoximes played a