Corbin Rex A, Ison Elon A, Abu-Omar Mahdi M
Brown Laboratory, Department of Chemistry, Purdue University, 560 Oval Drive, West Lafayette, Indiana 47907, USA.
Dalton Trans. 2009 Apr 21(15):2850-5. doi: 10.1039/b822783g. Epub 2009 Feb 25.
The cationic [2-(2'-hydroxyphenyl)-2-oxazolinato(-2)]oxorhenium(v) complex promotes oxidative dehydrogenation of organosilanes with water and alcohols in a catalytic manner to give excellent yields of silanols and silyl ethers, respectively. The reactions proceed conveniently under ambient and open-flask conditions with low catalyst loading (<or=1 mol%). The scope of the reaction with water is quite broad and includes aliphatic, aromatic, tertiary, secondary and primary silanes. The rate of reaction depends on the catalyst and silane concentrations and kinetic isotope effect measurements demonstrate involvement of the Si-H bond in the activated complex. The most influential factor on the silane affecting reactivity is steric hindrance and a quantitative correlation with the Taft steric parameter (E) is presented. A combination of kinetic data and isotope labelling results are used to discuss plausible mechanisms for the oxidative dehydrogenation reaction pathway.
阳离子型[2-(2'-羟基苯基)-2-恶唑啉基(-2)]氧铼(V)配合物以催化方式促进有机硅烷与水和醇的氧化脱氢反应，分别以优异的产率生成硅醇和硅醚。反应在环境条件和敞口烧瓶条件下以低催化剂负载量（≤1 mol%）方便地进行。与水的反应范围相当广泛，包括脂肪族、芳香族、叔、仲和伯硅烷。反应速率取决于催化剂和硅烷的浓度，动力学同位素效应测量表明活化络合物中涉及Si-H键。影响硅烷反应性的最主要因素是空间位阻，并给出了与塔夫脱空间参数（E）的定量相关性。结合动力学数据和同位素标记结果讨论了氧化脱氢反应途径的可能机理。
