脂环酮均相催化硅氢化反应的研究

Studies on Homogeneous Catalytic Hydrosilation of Cycloalkanonc

以(Ph_3P)_3RhCl作催化剂。苯为介质,利用原位傅立叶红外光谱技术和假一级动力学方法,对脂环酮的均相催化硅氢化反应进行了研究,考查了脂环嗣环及环硅氢化物环的大小对反应速率的影响,结果表明其活性顺序为:模型反应I:k_4>k_6>k_5>k_7;模型反应Ⅱ:k_5>k_5.提出了硅基对环酮羰基的迁移插入为反应的决定速率步骤.

The dependence of reactivity on ring size in hydrosilation of cycloalkanone with cyclosiliconhydrides catalyzed by (Ph3P)3RhCl was studied by 'in situ' FTIR technique.The results show that: 1. The rate constants of model reaction Ⅰ are arranged in decreasing order: k6>k5>k7; 2. The rate constants of model reaction Ⅱ are arranged in decreasing order: k5>k6. The migratory-insertion of silyl group to carbonyl group was proposed as the rate-determining step.