Enantioselective α-Boryl Carbene Transformations
Ming-Yao Huang, Jia-Bao Zhao, Cheng-Da Zhang, Yuan-Jun Zhou, Zhan-Sheng Lu, Shou-Fei Zhu*
*The State Key Laboratory and Institute of Elemento-Organic Chemistry, College of Chemistry, Nankai University, Tianjin 300071, China,
Email: sfzhu
nankai.edu.cn
M.-Y. Huang, J.-B. Zhao, C.-D. Zhang, Y.-J. Zhou, Z.-S. Lu, S.-F. Zhu, J. Am. Chem. Soc., 2024, 146, 9872-9879.
DOI: 10.1021/jacs.3c14766
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Abstract
Boryl cyclopropenes can be used as precursors for the swift synthesis of α-boryl metal carbenes, a powerful category of intermediates for chiral organoboron synthesis. These α-boryl carbenes undergo a series of highly enantioselective transfer reactions, including B-H and Si-H insertion, cyclopropanation, and cyclopropanation/Cope rearrangement, catalyzed by a singular chiral copper complex.
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Details
The article discusses the development of enantioselective α-boryl carbene transformations, focusing on the synthesis of chiral organoborons using boryl cyclopropenes as precursors. These α-boryl carbenes, generated through copper-catalyzed reactions, enable highly enantioselective transformations such as B−H and Si−H insertion, cyclopropanation, and cyclopropanation/Cope rearrangement. The research highlights the use of a chiral copper complex to facilitate these reactions, resulting in a variety of structurally diverse chiral organoboron compounds. Mechanistic studies indicate that the rate-determining step is the opening of the cyclopropene ring, with the Bpin group playing a crucial role in inducing chemoselectivity and stereocontrol. The findings expand the potential applications of α-boryl carbenes in chemical synthesis, providing new avenues for the creation of chiral molecules with significant synthetic utility. The study also includes computational analysis to understand the reaction mechanisms and the role of the Bpin group in stabilizing the carbene intermediates. This research paves the way for further exploration and development of functional chiral organoborons, leveraging the rich potential of carbene chemistry.
Key Words
1,1-borylboronates, 1,1-silylboronates
ID: J48-Y2024
