Herein we report a cascade cocatalysis strategy for the 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 catalyzed cyclization of alkynoic acids can smoothly engage in the subsequent chiral diphenylprolinol TMS-ether catalyzed Michael and Michael-aldol reactions. The cascade process serves as a general approach to chiral quaternary γ,γ-disubstituted butenolides.

中文翻译：

---

通过手性胺和路易斯酸级联共催化构建对映体富集的 γ,γ-二取代丁烯内酯

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。