Chiral Phosphine Catalyzed Asymmetric Michael Addition of Oxindoles

Bifunctional phosphines derived from amino acids mediate the asymmetric Michael addition of 3-substituted oxindoles to activated alkenes (see scheme). Biologically relevant chiral 3,3-disubstituted oxindoles were thus prepared in high yields and with excellent enantioselectivities from 3-aryl- and 3-alkyl-substituted oxindoles and various activated alkenes.