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. [ABSTRACT FROM AUTHOR]