Enantioselective Michael Addition of α-Substituted Cyanoacetates to Vinyl Ketones Catalyzed by Bifunctional Organocatalysts
作者:Tian-Yu Liu、Rui Li、Qian Chai、Jun Long、Bang-Jing Li、Yong Wu、Li-Sheng Ding、Ying-Chun Chen
DOI:10.1002/chem.200600796
日期:2007.1
A highly enantioselective Michael addition of alpha-substituted cyanoacetates to vinyl ketones was accomplished in the presence of simple bifunctional thiourea/tertiary amine organocatalysts. A number of alpha-aryl or alkyl cyanoacetates have been successfully applied to give multifunctional compounds with an all-carbon-substituted quaternary stereocenter in excellent enantioselectivities (82-97 %
在简单的双官能硫脲/叔胺有机催化剂的存在下,完成了α-取代的氰基乙酸酯向乙烯基酮的高度对映选择性迈克尔加成反应。许多α-芳基或氰基乙酸烷基酯已成功应用于具有全碳取代的季立构中心的多功能化合物,具有出色的对映选择性(82-97%ee)和收率(61-99%)。光学纯加合物可以平稳地转化为各种结构的β(2,2)-氨基酸酯。此外,基于加合物的绝对构型和计算研究,提出了一种有趣的反应模型,该模型涉及硫脲/叔胺催化剂和反应物之间的多个氢键相互作用。