南开大学朱守非团队近日实现了铜催化1-硅基环丙烯的高对映选择性开环/环丙烷化。2025年6月3日出版的《中国化学》杂志发表了这项成果。

手性环丙烷骨架是药物和天然产物等生物活性分子中至关重要的结构基序。通过过渡金属催化的卡宾转移实现烯烃的不对称环丙烷化是合成手性环丙烷最直接的方法之一。虽然在α-C取代卡宾的不对称环丙烷化方面取得了重大进展，但具有更大转化潜力的α-甲硅烷基卡宾的高度对映选择性环丙烷化在很大程度上仍未得到探索。

研究组报道了一种Cu（I）/手性双恶唑啉催化体系，该体系能够在α-甲硅烷基-α-烯基卡宾（由1-甲硅烷基环丙烯开环产生）和烯烃之间进行高度对映选择性的环丙烷化和环丙烷化/Cope重排反应。该方法提供了一系列含有立体季碳中心以及烯丙基硅烷部分和手性环庚二烯基硅烷的手性环丙基硅烷，从而扩大了手性有机硅化合物的多样性。理论计算表明，速率决定步骤涉及环丙烯的开环，其中甲硅烷基不仅决定开环的区域选择性，而且通过其空间和刚性性质显著影响反应的立体选择性。

附：英文原文

Title: Copper-Catalyzed Highly Enantioselective Ring-Opening/Cyclopropanation of 1-Silylcyclopropenes

Author: Xiao-Shuai Wen, Zhang-Wei Wang, Jia-Bao Zhao, Han-Chu Zhang, Ming-Yao Huang, Shou-Fei Zhu

Issue&Volume: 2025-06-03

Abstract: The chiral cyclopropane framework is a crucial structural motif in bioactive molecules such as pharmaceuticals and natural products. Asymmetric cyclopropanation of alkenes via transition metal-catalyzed carbene transfer represents one of the most direct approaches for synthesizing chiral cyclopropanes. While significant progress has been made in the asymmetric cyclopropanation of α-C-substituted carbenes, the highly enantioselective cyclopropanation of α-silyl carbenes, which possess greater transformation potential, remains largely unexplored. In this study, we report a Cu(I)/chiral bisoxazoline catalytic system that enables highly enantioselective cyclopropanation and cyclopropanation/Cope rearrangement reactions between α-silyl-α-alkenyl carbenes (generated from ring opening of 1-silyl cyclopropene) and alkenes. This methodology provides access to a series of chiral cyclopropylsilanes containing stereogenic quaternary carbon centers as well as allylic silane moieties and chiral cycloheptadienylsilanes, thereby expanding the diversity of chiral organosilicon compounds. Theoretical calculations reveal that the rate-determining step involves the ring opening of cyclopropene, where the silyl group not only dictates the regioselectivity of the ring opening but also significantly influences the stereoselectivity of the reaction through its steric and rigid properties.

DOI: 10.1002/cjoc.70100

Source: https://onlinelibrary.wiley.com/doi/10.1002/cjoc.70100