Highly Enantioselective Michael Addition of 3‐Aryloxindoles to Phenyl Vinyl Sulfone Catalyzed by Cinchona Alkaloid‐Derived Bifunctional Amine–Thiourea Catalysts Bearing Sulfonamide as Multiple Hydrogen‐Bonding Donors

A highly enantioselective Michael addition of 3‐aryloxindole to phenyl vinyl sulfone catalyzed by a quinine‐derived bifunctional amine–thiourea‐bearing sulfonamide as multiple hydrogen‐bonding donor catalyst has been investigated. The corresponding adducts, which contain a chiral quaternary carbon center at the 3‐position of the oxindole, were obtained in moderate‐to‐good yields (52–86 %) with high‐to‐excellent enantioselectivities (83–98 % ee).