Copper-Catalyzed Enantioselective Mukaiyama Aldol Reaction of Silyl Enol Ethers with Isatin-Derived Oxindolyl β,γ-Unsaturated α-Keto Esters

Enantioselective Mukaiyama 1,2 addition of silyl enol ethers with oxindolyl beta,gamma-unsaturated alpha-keto esters was developed under catalysis of a chiral L-Cu complex. The reaction was carried out rapidly under mild conditions, to give rise to a series of chiral beta-hydroxyl carbonyl compounds bearing oxindolyl backbone skeleton with high yields and excellent enantioselectivities, up to 99 %, as well as moderate to great diastereoselectivities, up to >20 : 1. This method provided an elegant synthesis route for the synthesis of such compounds.