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[摘要]：An organocatalytic asymmetric Michael addition reaction of 3-substituted oxindoles to protected 2-amino-1-nitroethenes has been developed. The reaction is catalyzed by a simple and readily available amino-indanol derivative and affords the desired products in very high yields (up to 99%) with excellent diastereoselectivities (up to > 99:1) and very good enantioselectivities (up to 90%). Significantly, this study provides a general catalytic method for the construction of 3,3'-disubstituted oxindoles bearing alpha,beta-diamino functionality as well as vicinal chiral quaternary/tertiary stereocenters. The potential utility of the protocol also had been demonstrated by gram-scale reaction and the versatile conversion of product. Furthermore, On the basis of the comprehensive experimental results and the absolute configuration of one of the Michael adducts, a work model was also proposed to explain the origin of asymmetric induction. |
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