Key Laboratory of Precise Synthesis of Functional Molecules of Zhejiang Province, Department of Chemistry, School of Science and Research Center for Industries of the Future, Westlake University, 600 Dunyu Road, Hangzhou, 310030, P. R. China.
Institute of Natural Sciences, Westlake Institute for Advanced Study, 18 Shilongshan Road, Hangzhou, 310024, P. R. China.
Nat Commun. 2023 Apr 15;14(1):2170. doi: 10.1038/s41467-023-37882-2.
Homogenous transition-metal catalysts bearing a chiral ligand are widely used for asymmetric hydrogenation of unsaturated compounds such as olefins and ketones, providing efficient concise access to products with chiral carbon centers. However, distinguishing the re and si prochiral faces of a double bond bearing two substituents that are sterically and electronically similar is challenging for these catalysts. Herein, we report a relay strategy for constructing compounds with a chiral gem-diaryl carbon center by means of a combination of selective arene exchange between 1,1-diarylethylenes or benzophenones with (naphthalene)Cr(CO) and subsequent asymmetric hydrogenation. During the hydrogenation, the Cr(CO) unit facilitate differentiation of the two prochiral faces of the substrate double bond via formation of a three-dimensional complex with one of the aromatic rings by selective arene exchange. Density functional theory calculations reveal that during the hydrogenation, chromium coordination affected π-π stacking of the substrate and the catalyst ligand, leading to differentiation of the prochiral faces.
手性配体负载的均相过渡金属催化剂广泛用于不饱和化合物（如烯烃和酮）的不对称氢化反应，为手性碳中心产物提供了高效简洁的合成途径。然而，对于这些催化剂来说，区分具有两个立体和电子相似取代基的双键的 re 和 si 前手性面是具有挑战性的。在此，我们报告了一种通过 1,1-二芳基乙烯或二苯甲酮与（萘）Cr(CO)之间的选择性芳基交换，然后进行不对称氢化反应，构建具有手性gem-二芳基碳中心化合物的接力策略。在氢化过程中，Cr(CO)单元通过选择性芳基交换与其中一个芳环形成三维络合物，从而促进底物双键的两个前手性面的区分。密度泛函理论计算表明，在氢化过程中，铬的配位作用影响了底物和催化剂配体的π-π堆积，导致前手性面的区分。
