Phosphine-Catalyzed Asymmetric [4+2] Annulation of Vinyl Ketones with Oxindole-Derived α,β-Unsaturated Imines: Enantioselective Syntheses of 2′,3′-Dihydro-1′ H-spiro[indoline-3,4′-pyridin]-2-ones.

A novel asymmetric [4+2] annulation of vinyl ketones with oxindole-derived α,β-unsaturated imines has been developed in the presence of a multifunctional thiourea-phosphine catalyst derived from a natural amino acid, providing the first phosphine-catalyzed enantioselective synthesis of 2′,3′-dihydro-1′ H-spiro[indoline-3,4′-pyridin]-2-ones in good yields with excellent stereoselectivities under mild conditions. [ABSTRACT FROM AUTHOR]