Diastereoselective synthesis of 3, 3-disubstituted oxindoles has been examined by transformations involving nucleophilic addition, alkylation, and cycloaddition using chiral racemic N-aryl oxindoles bearing C–N axial chirality. The most striking features of this approach are high diastereoselectivities (up to> 95:< 5) when using ortho-monosubstituted N-aryl oxindoles and easy removal of the p-(benzyloxy) aryl moiety in the axially twisted ...