Dichotomous Si–H Bond Activation by Alkoxide and Alcohol in Base-Catalyzed Dehydrocoupling of Silanes
作者:Evgenia D. Voronova、Igor E. Golub、Alexander Pavlov、Natalia V. Belkova、Oleg A. Filippov、Lina M. Epstein、Elena S. Shubina
DOI:10.1021/acs.inorgchem.0c01293
日期:2020.9.8
group on Si–H bond hydricity (quantified as hydride-donating ability, HDA) and Lewis acidity of silicon atom (characterized by maxima of molecular electrostatic potential) was accessed. Our results show the coordination of Lewis base (Y = Me3N, ROH, OR–) leads to the increased hydricity of pentacoordinate hypervalent Ph4-nSi(Y)Hn complexes and a decrease of the reaction barrier for H2 release. The formation
通过常规方法(使用多核NMR,IR和UV可见光谱法)和通过计算方法(在DFT M06 / 6-311 ++ G(d,p)理论水平)研究了在普通碱催化下硅烷与醇脱氢偶联的活化作用。对pH值的示例4- ñ的SiH ñ(ñ = 1-3)与(CF相互作用3)2 CHOH的Et的存在3 N.苯基基团数目和H的效果-通过取代的吸电子(CF 3)2 CHO –访问了Si-H键水合度(量化为氢化物给体能力,HDA)和硅原子的路易斯酸度(以分子静电势的最大值表征)的研究小组。我们的结果表明,路易斯碱(Y = Me 3 N,ROH或OR –)的配位导致五配位高价Ph 4- n Si(Y)H n配合物的羟基增加,并且H 2释放的反应障碍降低。叔配合物[Ph 4- n Si(Y)H n ]··HOR的形成是与醇盐作为理想活化剂进行脱氢偶联的关键前提。后者可以是外部的或内部的,由原位生成HOR去质子化。三级配合物(RO