Liu Tian-Yu, Li Rui, Chai Qian, Long Jun, Li Bang-Jing, Wu Yong, Ding Li-Sheng, Chen Ying-Chun
Key Laboratory of Drug-Targeting of Education Ministry and Department of Medicinal Chemistry, West China School of Pharmacy, Sichuan University, Chengdu 610041, China.
Chemistry. 2007;13(1):319-27. doi: 10.1002/chem.200600796.
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 % ee) and yields (61-99 %). The optical pure adducts could be smoothly converted to variously structured beta(2,2)-amino acid esters. Moreover, an interesting reaction model involving multiple hydrogen-bonding interactions amongst the thiourea/tertiary amine catalyst and the reactants has been proposed based on the absolute configuration of the adduct and computational studies.
在简单的双功能硫脲/叔胺有机催化剂存在下，实现了α-取代氰基乙酸酯与乙烯基酮的高度对映选择性迈克尔加成反应。多种α-芳基或烷基氰基乙酸酯已成功应用，以优异的对映选择性（82 - 97% ee）和产率（61 - 99%）得到具有全碳取代季碳立体中心的多功能化合物。光学纯加合物可顺利转化为各种结构的β(2,2)-氨基酸酯。此外，基于加合物的绝对构型和计算研究，提出了一个涉及硫脲/叔胺催化剂与反应物之间多重氢键相互作用的有趣反应模型。
