Assembly of Spirooxindole Derivatives Containing Four Consecutive Stereocenters via Organocatalytic Michael-Henry Cascade Reactions

A novel organocatalytic strategy for the synthesis of highly substituted spirocyclopentaneoxindoles was developed employing simple nitrostyrenes and 3-substituted oxindoles as starting materials. Michael-Henry cascade reactions, enabled through cinchona alkaloid organocatalysis, provided products in high yield and excellent enantioselectivity in a single step.