Organocatalytic Asymmetric Synthesis of Substituted 3-Hydroxy-2-oxindoles via Morita-Baylis-Hillman Reaction

We report a highly enantioselective Morita-Baylis-Hillman (MBH) reaction of isatins and acrolein to provide enantiomerically enriched 3-substituted 3-hydroxyoxindoles, which could serve as valuable synthetic building blocks. This is also the first time that a ketone has been used as the electrophile and acrolein as the nucleophile in a highly enantioselective catalytic asymmetric MBH reaction. Hatakeyama's catalyst, beta-isocupreidine (1), turned out to be a powerful catalyst for this transformation.