Zhang Yuanfei, Chen Zhe-Ning, Zhang Xiaofeng, Deng Xi, Zhuang Wei, Su Weiping
State Key Laboratory of Structural Chemistry, Fujian Institute of Research on the Structure of Matter, Chinese Academy of Sciences, 155 Yangqiao Road West, Fuzhou, 350002, PR China.
Center for Excellence in Molecular Synthesis, Chinese Academy of Sciences, Shanghai, 200032, PR China.
Commun Chem. 2020 Mar 31;3(1):41. doi: 10.1038/s42004-020-0287-0.
The prevalence of metalloenzymes with multinuclear metal complexes in their active sites inspires chemists' interest in the development of multinuclear catalysts. Studies in this area commonly focus on binuclear catalysts containing either metal-metal bond or electronically discrete, conformationally advantageous metal centres connected by multidentate ligands, while in many multinuclear metalloenzymes the metal centres are bridged through μ2-ligands without a metal-metal bond. We report herein a μ2-iodide-bridged binuclear palladium catalyst which accelerates the C-H nitrosation/annulation reaction and significantly enhances its yield compared with palladium acetate catalyst. The superior activity of this binuclear palladium catalyst is attributed to the trans effect-relay through the iodide bridge from one palladium sphere to the other palladium sphere, which facilitates dissociation of the stable six-membered chelating ring in palladium intermediate and accelerates the catalytic cycle. Such a trans effect-relay represents a bimetallic cooperation mode and may open an avenue to design and develop multinuclear catalysts.
活性位点含有多核金属配合物的金属酶的普遍存在激发了化学家对开发多核催化剂的兴趣。该领域的研究通常集中于含有金属-金属键或由多齿配体连接的电子离散、构象有利的金属中心的双核催化剂，而在许多多核金属酶中，金属中心通过不含金属-金属键的μ2-配体桥连。我们在此报告一种μ2-碘桥连双核钯催化剂，与醋酸钯催化剂相比，它能加速C-H亚硝化/环化反应并显著提高其产率。这种双核钯催化剂的卓越活性归因于通过碘桥从一个钯球到另一个钯球的反位效应传递，这促进了钯中间体中稳定的六元螯合环的解离并加速了催化循环。这种反位效应传递代表了一种双金属协同模式，可能为设计和开发多核催化剂开辟一条途径。
Zotero 插件
