A Highly Efficient and Practical New Allylboronate Tartramide for the Asymmetric Allylboration of Achiral Aldehydes
作者:Wansuo Chen、Yanzhu Liu、Zhirong Chen
DOI:10.1002/ejoc.200400670
日期:2005.4
Chiral homoallylic alcohols can be prepared from aldehydes upon reaction with two optically pure allylboronatetartramides. The enantiomeric excess is 10–15 % higher for the allylation of benzaldehyde when using N,N'-dibenzyl-tartramide auxiliary 5b than when using N,N'-diphenyl-tartramide (5a). 2-Allyl-N,N'-dibenzyl-1,3,2-dioxaborolane-4,5-dicarbamide (2b) affords homoallylic alcohols with 90–99 %
手性高烯丙醇可以由醛与两种光学纯的烯丙基硼酸酒石酰胺反应制备。使用 N,N'-二苄基酒石酰胺助剂 5b 时,苯甲醛烯丙基化的对映体过量比使用 N,N'-二苯基酒石酰胺 (5a) 时高 10–15%。2-Allyl-N,N'-dibenzyl-1,3,2-dioxaborolane-4,5-dicarbamide (2b) 在与一些代表性的醛反应后得到具有 90-99% ee 的高烯丙醇。衍生的手性助剂可以通过简单的重结晶回收,收率 85%,比旋光度没有任何损失。(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005)