Construction of Enantioenriched γ,γ-Disubstituted Butenolides Enabled by Chiral Amine and Lewis Acid Cascade Cocatalysis
作者:Chenguang Yu、Peng Ji、Yueteng Zhang、Xiang Meng、Wei Wang
DOI:10.1021/acs.orglett.1c02916
日期:2021.10.1
facile construction of chiral γ,γ-disubstituted butenolides. The synthetic manifold employs simple alkynoic acids instead of the preformed silyloxy furans or 5-substituted furan-2(3H)-ones. In situ formed 5-substituted furan-2(3H)-ones by AgNO3 or Ph3PAuCl/AgOTf catalyzedcyclization of alkynoic acids can smoothly engage in the subsequent chiral diphenylprolinol TMS-ether catalyzed Michael and Michael-aldol
在此,我们报告了一种用于轻松构建手性 γ,γ-二取代丁烯内酯的级联共催化策略。合成歧管使用简单的炔酸代替预先形成的甲硅烷氧基呋喃或 5-取代呋喃-2(3 H )-酮。通过AgNO 3或Ph 3 PAuCl/AgOTf 催化的炔酸环化原位形成的5-取代呋喃-2(3 H )-酮可以顺利地参与随后的手性二苯基脯氨醇TMS-醚催化的迈克尔和迈克尔-羟醛反应。级联过程是手性季 γ,γ-二取代丁烯内酯的通用方法。
Highly Enantioselective Direct Vinylogous Michael Addition of γ-Butenolide to Enals
An unprecedented and simple direct vinylogous addition of deconjugated butenolide to enals has been developed in excellent stereoselectivities (> 95% ee), with Aminal-PYrrolidine (APY) catalyst. This methodology allows for the efficient preparation of complex gamma-butenolide from readily available renewable resources. Furthermore, preliminary mechanistic investigations have allowed for the better understanding of the origin of both stereoselectivities and of the observed high reactivities.