南方科技大学化学系刘心元课题组在自由基不对称化学领域取得一项新成果，经过不懈努力，他们开发出铜催化的立体汇聚式自由基碳(Sp3)-碳(Sp2)键铃木宫浦交叉偶联反应。 2020年11月4日，国际知名学术期刊《美国化学会志》发表了这一成果。

该研究确立了一种由铜催化的、在各种外消旋的烷基卤代烃和有机硼酸酯之间发生的立体汇聚式碳(Sp3)-碳(Sp2)键铃木-宫浦交叉偶联反应。反应成功的关键是使用了一个由金鸡纳碱衍生的手性N, N, P-配体，这一配体不仅促进了铜催化剂的还原性，使反应更倾向于采取去手性的自由基途径而不是手性保持的S_N2途径，同时还为在高反应活性的自由基中获得极具挑战性的手性控制提供了理想的手性环境。

该反应对交叉偶联的两种底物具有普适性，可兼容芳基和杂原子芳基取代的硼酸酯以及苯基、杂原子苯基、炔基溴化物和氯化物。因此，该反应为合成一系列以手性苯基叔碳中心为特征的有用的富手性骨架提供了一条便利的途径。

附：英文原文

Title: Copper-Catalyzed Enantioconvergent Radical Suzuki–Miyaura C(sp3)–C(sp2) Cross-Coupling

Author: Sheng-Peng Jiang, Xiao-Yang Dong, Qiang-Shuai Gu, Liu Ye, Zhong-Liang Li, Xin-Yuan Liu

Issue&Volume: November 4, 2020

Abstract: A copper-catalyzed enantioconvergent Suzuki–Miyaura C(sp3)–C(sp2) cross-coupling of various racemic alkyl halides with organoboronate esters has been established in high enantioselectivity. Critical to the success is the use of a chiral cinchona alkaloid-derived N,N,P-ligand for not only enhancing the reducing capability of copper catalyst to favor a stereoablative radical pathway over a stereospecific SN2-type process but also providing an ideal chiral environment to achieve the challenging enantiocontrol over the highly reactive radical species. The reaction has a broad scope with respect to both coupling partners, covering aryl- and heteroarylboronate esters, as well as benzyl-, heterobenzyl-, and propargyl bromides and chlorides with good functional group compatibility. Thus, it provides expedient access toward a range of useful enantioenriched skeletons featuring chiral tertiary benzylic stereocenters.

DOI: 10.1021/jacs.0c09125

Source: https://pubs.acs.org/doi/10.1021/jacs.0c09125