摘要
氯铂酸是迄今最通用的硅氢加成反应的有效催化剂,然而它对某些带官能基团的烯烃的催化硅氢加成反应并不理想.以氯铂酸催化氯丙烯与含氢氯硅烷的反应为例,反应诱导期较长,产率低.由于该反应的产物是制备特种聚有机硅氧烷和硅烷偶联剂的重要单体,因此探索新的高效催化剂的研究一直很活跃.
In the hydrosilylation of allyl chloride by dichloromethylsilane, the catalyst system of PPhs/H2PtCl6molar ratio 1:1 gave 68% yield of 3-chloropropyl-methyldichlorosilane after one hour of reaction, while chloroplatinic acid gave only 12% yield.For the addition of trichlorosilane to allyl chloride, the former catalyst system made the reaction to be carried out rapidly without any induction period even at room temperature, the yield of product 3-chloropropyltri-chlorosilane was as high as 85%. At the same conditions, the reaction catalyzed by chloroplatinic acid gave only 58% yield.In the hydrosilylation of allyl chloride with dichloromethylsilane, when 1.0 to 1.5 molar ratio of PPh3/H2-PtCl8 was used, the catalyst system showed the highest activity and good selectivity.The catalyst system was also found to be active for the hydrosilylation of heptene-1 and allyl acetate by dichloromethylsilane or trichlorosilane. The effect of the structure of hydrosilanes and olefins on the rate of hydrosilylation was discussed.
