Copper-catalyzed enantioselective Mukaiyama aldol reaction of silyl enol ethers with isatins

A highly enantioselective Mukaiyama aldol reaction of silyl enol ethers with isatins was developed. A series of chiral 3-substituted 3-hydroxy-2-oxindoles could be obtained exclusively with high yields (up to 95%) and excellent enantioselectivities (up to 99%). In particular, water was essential to improve the diastereoselectivity.