Asymmetric Addition of Indoles to Isatins Catalysed by Bifunctional Modified Cinchona Alkaloid Catalysts

(Figure Presented) Simple and selective: An efficient organocatalytic enantioselective method for the synthesis of substituted-3-hydroxyoxindole derivatives with a quaternary chiral carbon has been developed. The cinchona alkaloid derived catalyst catalyses the Friedel Crafts-type addition of indole derivatives to the isatin derivatives under mild conditions to provide substituted 3-hydroxyoxindoles in good to excellent yields with high enantioselectivity (see scheme). © 2010 Wiley-VCH Verlag GmbH&Co. KGaA, Weinheim.