Enantioselective Michael Reaction of Cyclic β‑Ketoesters with Morita–Baylis–Hillman Derivatives Using a Phase-Transfer Catalyst

This study aims to develop a highly enantioselective Michael reaction of cyclic β-ketoesters with Morita–Baylis–Hillman (MBH) derivatives using a phase-transfer catalyst. Cyclic β-ketoesters reacted with MBH derivatives to stereoselectively generate a quaternary carbon center in the presence of cinchona alkaloid-derived bulky ammonium catalyst, and aqueous KOH and Michael adducts bearing an acrylate moiety were obtained in good chemical yields with good enantioselectivity.