中国科学技术大学黄汉民团队报道了自由基分化导致的两个烯丙基C-H键的选择性羰基化环化。相关研究成果于2024年7月9日发表于国际一流学术期刊《美国化学会志》。

控制C–H官能化的位点选择性在合成有机化学中具有重要意义和艰巨的任务，推动了激活C–H键的高效和可持续技术的持续发展。然而，控制双C–H官能化的位点选择性的方法很少。

该文中，研究人员一种概念上的新方法，通过实施激进的单挑策略来实现高度位点选择性的C–H功能化。利用空间位阻敏感的CO插入作为自由基分化过程，在没有特殊和复杂的HAT试剂的情况下，通过顺序的双烯丙基C–H键活化，建立了亚胺和烯烃的位点选择性和立体选择性的羰基化形式[2+2]环加成。

该反应与多种具有不同骨架的烯烃和亚胺相容，以递送具有合成和药用价值的烯丙基β-内酰胺。

附：英文原文

Title: Site-Selective Carbonylative Cyclization with Two Allylic C–H Bonds Enabled by Radical Differentiation

Author: Yongzheng Ding, Jianing Wu, Tianze Zhang, Hongchi Liu, Hanmin Huang

Issue&Volume: July 9, 2024

Abstract: Controlling the site-selectivity of C–H functionalization is of significant importance and a formidable undertaking in synthetic organic chemistry, motivating the continuing development of efficient and sustainable technologies for activating C–H bonds. However, methods that control the site-selectivity for double C–H functionalization are rare. We herein report a conceptually new method to achieve  highly site-selective C–H functionalization by implementing a radical single-out strategy. Leveraging the steric hindrance-sensitive CO-insertion as the radical differentiation process, a site-selective and stereoselective carbonylative formal [2 + 2] cycloaddition of imines and alkenes by sequential double allylic C–H bond activation was established without special and complicated HAT-reagents. This reaction was compatible with a wide range of alkenes and imines with diverse skeletons to deliver allylic β-lactams that are of synthetic and medicinal interest.

DOI: 10.1021/jacs.4c05360

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c05360