Wang Peng-Zi, Zhang Zhihan, Jiang Min, Chen Jia-Rong, Xiao Wen-Jing
Engineering Research Center of Photoenergy Utilization for Pollution Control and Carbon Reduction, Ministry of Education; College of Chemistry, Central China Normal University, 152 Luoyu Road, Wuhan, Hubei, 430079, China.
College of Materials, Chemistry and Chemical Engineering, Hangzhou Normal University, Hangzhou, 310036, China.
Angew Chem Int Ed Engl. 2024 Oct 21;63(43):e202411469. doi: 10.1002/anie.202411469. Epub 2024 Sep 17.
Radical-involved arylative cross-coupling reactions have recently emerged as an attractive strategy to access valuable aryl-substituted motifs. However, there still exist several challenges such as limited scope of radical precursors/acceptors, and lack of general asymmetric catalytic systems, especially regarding the multicomponent variants. Herein, we reported a general copper-Box system for asymmetric three-component arylative radical cross-coupling of vinylarenes and 1,3-enynes, with oxime carbonates and aryl boronic acids. The reactions proceed under practical conditions in the absence or presence of visible-light irradiation, affording chiral 1,1-diarylalkanes, benzylic alkynes and allenes with good enantioselectivities. Mechanistic studies imply that the copper/Box complexes play a dual role in both radical generation and ensuing asymmetric cross-coupling. In the cases of 1,3-enynes, visible-light irradiation could improve the activity of copper/Box complex toward the initial radical generation, enabling better efficiency match between radical formation and cross-coupling.
涉及自由基的芳基化交叉偶联反应最近已成为一种获得有价值的芳基取代基序的有吸引力的策略。然而，仍然存在一些挑战，例如自由基前体/受体的范围有限，以及缺乏通用的不对称催化体系，特别是在多组分变体方面。在此，我们报道了一种通用的铜-Box体系，用于乙烯基芳烃和1,3-烯炔与肟碳酸酯和芳基硼酸的不对称三组分芳基化自由基交叉偶联反应。该反应在有无可见光照射的实际条件下进行，得到具有良好对映选择性的手性1,1-二芳基烷烃、苄基炔烃和丙二烯。机理研究表明，铜/Box配合物在自由基生成和随后的不对称交叉偶联中都起着双重作用。在1,3-烯炔的情况下，可见光照射可以提高铜/Box配合物对初始自由基生成的活性，使自由基形成和交叉偶联之间具有更好的效率匹配。
