我们通过概念上不同的扩环策略开发了一种有效的中环和大环内酯合成方法。The design of an unprecedented ring conjunction mode of oxetene, combined with the appropriate choice of a Lewis acid promoter and an additive, constitutes the key components of the new process. 通过这种新方法,反应不需要高度稀释或缓慢添加。
Synthesis of medium-sized lactones from siloxy alkynes via ring expansion
作者:An Wu、Wanxiang Zhao、Jianwei Sun
DOI:10.1016/j.tet.2020.131163
日期:2020.12
topic in organic synthesis due to the disfavored kinetic and thermodynamic features. Herein we detail an efficient intermolecular process using siloxyalkynes as substrates and oxetene ring expansion as the key strategy. With extension to a new silyl-masked alkyne, this reaction now features a broad scope, high efficiency, and mild conditions.
Catalytic Ring Expansion of Cyclic Hemiaminals for the Synthesis of Medium‐Ring Lactams
作者:Wanxiang Zhao、Hui Qian、Zigang Li、Jianwei Sun
DOI:10.1002/anie.201504926
日期:2015.8.17
A mild and efficient intermolecular ring‐expansion approach was developed for the synthesis of medium‐ringlactams by using siloxy alkynes. Key to success is the suitable combination of a superior catalyst and an exceptional nitrogen‐protecting group. Control experiments indicated that the reaction is remarkably selective toward the desired lactam formation, even with many possible non‐productive pathways
An efficient [3+2] annulation for the asymmetric synthesis of densely-functionalized pyrrolidinones and γ-butenolides
作者:Hui Qian、Song Sun、Wanxiang Zhao、Jianwei Sun
DOI:10.1039/d0cc05188h
日期:——
[3+2] annulation of siloxy alkynes that provides robust access to highly enantioenriched, densely-substituted pyrrolidinones and γ-butenolides, whose direct synthesis remains challenging. This process also represents a rare asymmetricsynthesis of enantrioenriched molecules from siloxy alkynes.
A [3+2] Cyclization of Siloxyalkynes and Isocyanides for the Synthesis of Oxazoles
作者:An Wu、Jianwei Sun
DOI:10.1055/s-0037-1610402
日期:2019.3
A mild and efficient [3+2] cyclization of siloxyalkynes for the synthesis of aromatic heterocycles is developed. It is a new addition to the cyclization reactions of these versatile species. In the presence of TBAF as promoter, siloxyalkynes react with electron-withdrawing isocyanides to form a range of oxazole products. In this reaction, siloxyalkynes contribute the C–O unit for the cyclization, which