Tang Sheng, Xu Hui, Dang Yanfeng, Yu Shouyun
State Key Laboratory of Analytical Chemistry for Life Science, Jiangsu Key Laboratory of Advanced Organic Materials, Chemistry and Biomedicine Innovation Center (ChemBIC), School of Chemistry and Chemical Engineering, Nanjing University, Nanjing 210023, China.
Tianjin Key Laboratory of Molecular Optoelectronic Sciences, Department of Chemistry, School of Science, Tianjin University, Tianjin 300072, China.
J Am Chem Soc. 2024 Oct 2;146(39):27196-27203. doi: 10.1021/jacs.4c11145. Epub 2024 Sep 17.
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.
C-H键的官能团化通过消除对底物预活化的需求，简化了复杂分子的合成。传统上，在铜催化下将烯丙基C-H键直接氧化为烯丙基酯的卡拉施-索斯诺夫斯基反应，一直受到反应时间长、底物范围有限以及与无环烯烃的对映选择性低的阻碍。在此，我们提出了一种新颖的、可见光驱动的、铜催化的不对称卡拉施-索斯诺夫斯基反应，该反应克服了这些挑战。该方法将底物范围扩大到包括无环内烯烃，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，并在生成烯丙基C-H酰氧基化产物方面实现了卓越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官能团化技术，为合成手性分子提供了一种更高效、更可持续的方法。
