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

Abstract

Abstract 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. magnified image