Synthesis of <i>N</i>-Alkoxycarbonyl Ketimines Derived from Isatins and Their Application in Enantioselective Synthesis of 3-Aminooxindoles
作者:Wenjin Yan、Dong Wang、Jingchao Feng、Peng Li、Depeng Zhao、Rui Wang
DOI:10.1021/ol3007953
日期:2012.5.18
A simple and generalmethod in the synthesis of N-alkoxycarbonyl ketimines derived from isatins has been described first. Generally, the enantioselective addition of 1,3-dicarbonyl compounds to this kind of ketimine affords chiral 3-amino oxindoles in high yield and excellent ee.
catalyzed by chiral Cinchona alkaloid based squaramide containing H-bond donor catalysts, wherein, the reaction of 1,3-diketones with isatin (N-Boc) ketimines led to the formation of 3-aminooxindole derivatives. These derivatives were obtained in high yields with excellent enantioselectivities under mild conditions using 3 mol% of the catalyst. This protocol provides valuable and easy access to chiral 3-substituted
Asymmetric organocatalytic direct Mannich reaction of acetylacetone and isatin derived ketimines: Low catalyst loading in chiral cinchona-squaramides
作者:Duygu İşibol、Seda Karahan、Cihangir Tanyeli
DOI:10.1016/j.tetlet.2017.12.081
日期:2018.2
A highly enantioselective synthesis of 3-amino-2-oxindoles by directMannichreaction between acetylacetone and N-carbamoyl isatin ketimine has been described herein. Corresponding chiral adducts were obtained in high yields (up to 98%) and with excellent enantioselectivities (up to >99% ee) by very low (1 mol%) catalyst loading of 2-adamantyl substituted bifunctional cinchona-squaramide.