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

Abstract

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). We have developed a highly effective enantioselective Michael addition of 3-aryloxindoles to phenyl vinyl sulfone catalyzed by a quinine-derived bifunctionalamine-thiourea-bearing sulfonamide as multiple hydrogen-bonding donor catalyst, which provides the corresponding adducts in moderate-to-good yields (52-86%) and with good-to-excellent enantioselectivities (83-98%). © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.