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

• Published in: Journal of the American Chemical Society Vol. 142; no. 46; pp. 19652 - 19659
• Main Authors: Jiang, Sheng-Peng, Dong, Xiao-Yang, Gu, Qiang-Shuai, Ye, Liu, Li, Zhong-Liang, Liu, Xin-Yuan
• Format: Journal Article
• Language: English
• Published: WASHINGTON American Chemical Society 18.11.2020; Amer Chemical Soc
• Subjects: catalysts; Chemistry; Chemistry, Multidisciplinary; Cinchona; cross-coupling reactions; enantioselectivity; Physical Sciences; Science & Technology; stereospecificity; HALIDES; STEREOSPECIFIC FORMATION; ARYLATION
• ISSN: 0002-7863; 1520-5126; 1520-5126
• DOI: 10.1021/jacs.0c09125

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.