Asymmetric organocatalytic conjugate addition of dialkyl phosphites to N-unprotected isatylidene malononitriles: access to 3-phospho-2-oxindoles with chiral quaternary stereocenters
作者:Zhao-Min Liu、Nai-Kai Li、Xiao-Fei Huang、Bing Wu、Ning Li、Chun-Yuen Kwok、Yong Wang、Xing-Wang Wang
DOI:10.1016/j.tet.2014.02.023
日期:2014.4
established for the first time by using a simple bifunctional tertiary amine–thiourea catalyst. The corresponding adducts, 3-phospho-2-oxindoles, containing a chiral quaternary carbon center at the 3-position of the oxindole, were obtained in good to excellent yields (up to 98%) with moderate to excellent enantioselectivities (up to 95% ee). In addition, optically active 3,3′-disubstituted oxindoles bearing carboxylate
通过使用简单的双功能叔胺-硫脲催化剂,首次建立了亚磷酸二烷基酯对N-未保护的异亚丙基丙二腈的对映选择性迈克尔加成反应。获得了相应的加合物3-磷酸-2-氧吲哚,在羟吲哚的3位上含有一个手性季碳中心,收率良好至优异(最高98%),对映选择性中等(优异至95%) ee)。另外,通过迈克尔加合物的氧化降解,可以容易地获得带有羧酸根和膦酸酯基的旋光的3,3′-二取代的羟吲哚。