Department of Chemistry, Graduate School of Science, Osaka Prefecture University, Gakuen-cho, Naka-ku, Sakai, Osaka 599-8531, Japan.
Fukui Institute for Fundamental Chemistry, Kyoto University, Takano-nishihiraki-cho 34-4, Sakyo-ku, Kyoto 606-8103, Japan.
J Am Chem Soc. 2020 Aug 19;142(33):14039-14044. doi: 10.1021/jacs.0c04690. Epub 2020 Aug 11.
A new mode of bond activation involving M→Z interactions is disclosed. Coordination to transition metals as σ-acceptor ligands was found to enable the activation of fluorosilanes, opening the way to the first transition-metal-catalyzed Si-F bond activation. Using phosphines as directing groups, sila-Negishi couplings were developed by combining Pd and Ni complexes with external Lewis acids such as MgBr. Several key catalytic intermediates have been authenticated spectroscopically and crystallographically. Combined with DFT calculations, all data support cooperative activation of the fluorosilane via Pd/Ni→Si-F→Lewis acid interaction with conversion of the Z-type fluorosilane ligand into an X-type silyl moiety.
本文揭示了一种涉及 M→Z 相互作用的新型键激活模式。研究发现，过渡金属的配位作为σ-受体配体能够激活氟硅烷，从而开辟了首例过渡金属催化的 Si-F 键激活的途径。通过将 Pd 和 Ni 配合物与外部路易斯酸（如 MgBr）结合，使用膦作为导向基团，发展了硅烷-Negishi 偶联反应。已经通过光谱和晶体学方法鉴定了几个关键的催化中间体。结合密度泛函理论计算，所有数据均支持通过 Pd/Ni→Si-F→路易斯酸相互作用协同激活氟硅烷，将 Z 型氟硅烷配体转化为 X 型硅基部分。
