Highly Enantioselective Construction of Spiro[<i>4H</i>-pyran-3,3′-oxindoles] Through a Domino Knoevenagel/Michael/Cyclization Sequence Catalyzed by Cupreine

Abstract

The first enantioselective organocatalytic two- and three-component reactions via a domino Knoevenagel/Michael/cyclization sequence with cupreine as catalyst have been developed. A wide range of optically active spiro[4H-pyran-3,3'-oxindoles] were obtained in excellent yields (up to 99%) with good to excellent enantioselectivities (up to 97%) from simple and readily available starting materials under mild reaction conditions. These heterocyclic spirooxindoles will provide promising candidates for chemical biology and drug discovery.