由于相似的动力学反应曲线,从多官能化前体开始合成硅烷通常会遇到化学选择性低的问题,导致难以分离的副产物的形成。相反的方法是基于非反应性四烷基硅烷作为起始材料的方法,但目前尚未开发。据报道,利用我们实验室最近开发的硅离子引发的四烷基硅烷化学选择性卤脱烷基化,该方案的扩展,即从四烷基硅烷直接合成二卤硅烷。经过一系列卤代脱氢和卤代脱烷基化,三烷基氢硅烷也可以转化为二卤代硅烷。市售的 1,2-二卤乙烷充当卤素源,并通过苯溶剂的 S E Ar 取代参与生成催化活性芳烃离子。假设形成不常见的卤素取代的硅离子作为中间体,这可能是需要升高反应温度的原因。
This invention relates to a process for preparing tetrahydrocarbylsilane in high yield, comprising: a) forming a reaction mass from molten metal and trihydrocarbylaluminum, in an hydrocarbon solvent under an inert gas atmosphere; b) maintaining the reaction mass at a temperature in the range of from about 100.degree. to about 130.degree. C. for a period of time sufficient to form sodium tetrahydrocarbylaluminate; c) contacting the sodium tetrahydrocarbylaluminate with organotrihalosilane; and d) heating the contacted tetrahydrocarbylaluminate and organotrihalosilane to a temperature and for a period of time sufficient to form the tetrahydrocarbylsilane, wherein the tetrahydrocarbylaluminate and tetrahydrocarbylsilane are formed at a pressure of less than about 3000 KPa and wherein the hydrocarbyl group of the tetrahydrocarbyl silane is one or a mixture of hydrocarbyl groups having less than about 8 carbon atoms each.
Heterogenization of Rh(II) porphyrin catalysts in a metal–organic framework is crucial for catalyst turnover in thermal olefin hydrosilylation and hydrogermylation. Unlike MOF-supported metalloradical catalysts, homogeneous analogues convert to closed shell species that obstruct catalytic turnover. Site-isolated Rh(II) metalloradicals are readily accessed via MOF synthesis with a linker containing