作者:Mouâd Alami、Abdallah Hamze、Olivier Provot、Jean-Daniel Brion
DOI:10.1055/s-2007-983742
日期:2007.7
The platinum-catalyzed hydrosilylation of unsymmetrical substituted arylalkynes with various hydrosilanes was investigated and the reaction selectivity of various para-substituted substrates was compared with that of their corresponding ortho-substituted derivatives. We showed that heterogeneous platinum oxide is a very efficient catalyst for such hydrosilylations and that H-Si bond addition proceeds in a stereoselective cis-fashion. The regioselectivity was found to be under the control of the ortho-substituent rather than due to the nature of the platinum catalyst. Arylalkynes with an ortho-substituent provided predominantly to exclusively α-selectivity, regardless of the electronic nature of the substituent. The precise contributions of steric, electronic, and coordinative factors controlling the regioselectivity of the H-Si bond addition are discussed.
对不对称取代的芳基炔与各种氢硅烷的铂催化氢硅化反应进行了研究,并比较了不同对位取代底物的反应选择性与其相应的邻位取代衍生物的反应选择性。我们展示了异相铂氧化物是一种高效的催化剂用于此类氢硅化反应,且H-Si键的加成以立体选择性的顺式方式进行。区域选择性被发现是由邻位取代基控制,而不是由铂催化剂的性质决定。带有邻位取代基的芳基炔提供了主要到完全的α-选择性,无论取代基的电子性质如何。我们还讨论了影响H-Si键加成的区域选择性的立体、电子和配位因素的精确贡献。