A Proton-Switchable Bifunctional Ruthenium Complex That Catalyzes Nitrile Hydroboration
A Proton-Switchable Bifunctional Ruthenium Complex That Catalyzes Nitrile Hydroboration
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DOI：
10.1021/jacs.5b08406
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发表时间：
2015-10-14
影响因子：
15
通讯作者：
Szymczak, Nathaniel K.
中科院分区：
文献类型：
--
作者：
Geri, Jacob B.;Szymczak, Nathaniel K.
一个新的双功能钳形配体框架轴承悬垂的质子响应性羟基的制备和金属化与Ru（II），随后在四个离散的质子化状态分离。与H-2和HBPin的化学计量反应显示出跨越Ru（II）-O键的容易的E-H（E = H或BPin）活化，提供了与相邻质子和硼原子具有强相互作用的不寻常的Ru H物种的途径。发现这些配合物在温和条件下促进酮和腈的催化硼氢化反应，并且活性高度依赖于配体的质子化状态。机理实验揭示了侧羟基对催化活性的关键作用。
A new bifunctional pincer ligand framework bearing pendent proton-responsive hydroxyl groups was prepared and metalated with Ru(II) and subsequently isolated in four discrete protonation states. Stoichiornetric reactions with H-2 and HBPin showed facile E-H (E = H or BPin) activation across a Ru(II)-O bond, providing access to unusual Ru H species with strong interactions with neighboring proton and boron atoms. These complexes were found to promote the catalytic hydroboration of ketones and nitriles under mild conditions, and the activity was highly dependent on the ligand's protonation state. Mechanistic experiments revealed a crucial role of the pendent hydroxyl groups for catalytic activity.