南京大学俞寿云团队报道了光激发铜催化无环内烯烃的对映选择性烯丙基C(sp3) -H酰基化。相关研究成果于2024年9月17日发表在国际顶尖学术期刊《美国化学会杂志》。

C-H键的功能化通过消除底物预活化的需要简化了复杂分子的合成。传统上，在铜催化下直接将烯丙基C-H键氧化成烯丙基酯的Kharasch-Sosnovsky反应，受到反应时间长、底物范围有限和无环烯烃的对映选择性低的阻碍。

该文中，研究人员提出了一种新的、可见光驱动的、铜催化的不对称Kharasch-Sosnovsky反应，克服了这些挑战。

该方法将底物范围扩展到包括无环内烯烃，并使用环保的可见光催化改善了反应条件。它增强了自由基反应性，在生产烯丙基C-H酰氧基化产物时，实现了优异的对映选择性和区域选择性。这一突破显著推进了直接C-H官能化技术，为合成手性分子提供了一种更高效、更可持续的方法。

附：英文原文

Title: Photoexcited Copper-Catalyzed Enantioselective Allylic C(sp3)–H Acyloxylation of Acyclic Internal Alkenes

Author: Sheng Tang, Hui Xu, Yanfeng Dang, Shouyun Yu

Issue&Volume: September 17, 2024

Abstract: The functionalization of C–H bonds streamlines the synthesis of complex molecules by eliminating the need for substrate preactivation. Traditionally, the Kharasch–Sosnovsky reaction, which directly oxidizes allylic C–H bonds into allylic esters under copper catalysis, has been hampered by long reaction times, limited substrate scope, and low enantioselectivity with acyclic olefins. Herein, we present a novel, visible light-driven, copper-catalyzed asymmetric Kharasch–Sosnovsky reaction that overcomes these challenges. This method expands the substrate scope to include acyclic internal alkenes and improves reaction conditions using eco-friendly visible light catalysis. It enhances radical reactivity and achieves superior enantioselectivity and regioselectivity in producing allylic C–H acyloxylation products. This breakthrough significantly advances direct C–H functionalization techniques, offering a more efficient and sustainable approach to synthesizing chiral molecules.

DOI: 10.1021/jacs.4c11145

Source: https://pubs.acs.org/doi/abs/10.1021/jacs.4c11145