A diastereo- and enantio-selective domino Michael-cyclization–tautomerization reaction of isatylidene malononitriles with α,α-dicyanoalkenes catalyzed by a cinchona alkaloid-derived bifunctional thiourea catalyst has been developed. A series of multi-functionalized spiro oxindole diene derivatives have been obtained in good to excellent yields (up to 97%) with good to excellent enantioselectivities (up to 96%) as well as good diastereoselectivities (up to 7.9 : 1). In addition, an anomalous temperature effect on the enantioselectivity has also been studied for this transformation.
已开发出一种异构体和对应选择性多米诺迈克尔环化-
异亚丙基丙二腈与α,α-二
氰基烯烃的环化-互变异构选择性反应,该反应由
金鸡纳
生物碱衍生的双功能
硫脲催化剂催化。已获得一系列多功能化的螺环
吲哚二烯衍
生物,其产率良好至极佳(高达97%),对应选择性良好至极佳(高达96%),以及立体选择性良好(高达7.9:1)。此外,还研究了这种转化中温度对对应选择性的异常影响。