Enantioselective synthesis of spiroimidazolones by synergistic catalysis

The present study investigates an enantioselective cyclization of enals with imidazolone derivatives catalyzed by a combination of achiral Pd(0) complex and chiral secondary amine. Corresponding spirocyclic imidazolones were produced in high yields with moderate diastereoselectivity and excellent enantioselectivity. The developed co-operative catalytic methodology provides a highly substituted spirocyclic scaffold with four stereogenic centers under mild conditions. [Display omitted] •Synergistically catalyzed reaction leading to spirocyclic compounds.•Combination of chiral secondary amine and achiral palladium complex as catalysts.•Preparation of a wide variety of chiral spiroimidazolones.•Readily derivatization of prepared chiral spiroimidazolones.