Catalytic Asymmetric Addition of Alkyl Enol Ethers to 1,2‐Dicarbonyl Compounds: Highly Enantioselective Synthesis of Substituted 3‐Alkyl‐3‐Hydroxyoxindoles

A familiar ring: An efficient catalytic asymmetric hetero-ene reaction of 1,2-dicarbonyl compounds (including isatins, α-ketoesters, and glyoxal derivatives) is described. The catalyst system derived from 1 can be used for a broad substrate scope and the corresponding products were obtained in good yield and excellent enantioselectivity. M.S.=molecular sieves.