Study of Catalytic Conversion of Organosilicon Compounds
Grant-in-Aid for General Scientific Research (C)
|Allocation Type||Single-year Grants|
|Research Institution||Ehime University|
YAMAGUCHI Tsutomu Ehime University, Department of Applied Chemistry, Professor, 工学部, 教授 (10000861)
|Project Period (FY)
1994 – 1995
Completed(Fiscal Year 1995)
|Budget Amount *help
¥1,900,000 (Direct Cost : ¥1,900,000)
Fiscal Year 1995 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1994 : ¥1,200,000 (Direct Cost : ¥1,200,000)
|Keywords||organosilane / solid superacid / alkylation / solid acid / disproportionation / hydrosilylation / 触媒|
Although numerous works on catalytic reactions of hydrocarbons have been done, only few research works have been carried out on transformations of organosilanes, in spite of an increasing importance of their application to various fields. Both in laboratories and industries, reactions of organosilane are usually performed in a homogeneous liquid phase using metal halides and transition metal complexes. The development of fundamental chemistries of Si compounds in heterogeneous catalysis is quite attractive and important challenge.Hence the disproportionation and the alkylation of alkylsilanes were examined.
1.Dispropotionation of alkylsialnes
For the disproportionation reaction of diethylsilane (E2) and diethyldimethylsilane (E2M2), only strongly acidic catalysts, SiO_2-Al_2O_3 (SA), alumina and sulfated ZrO_2 (SO_3/ZrO_2), exhibited high activities. On weakly acidic catalysts a cracking reaction was operative. Although the dispropotionation reaction was only the reaction at lower reacti
on temperatures, an increase of reaction temperature resulted in the increase of the cracking reaction regardless the reactants and the catalysts.
The relative reactivity of organosilanes was in the order of E2M2>E2 on SiO_2-Al_2O_3 and SO_3/ZrO_2, while the order on alumina was found to be E2>E2M2. This strongly suggests that differnt types of mechanisms are operative ; a hydride abstraction and a proton addition are the initiation step of the reaction over Al_2O_3 and SO_3/ZrO_2, respectively.
2.Alkylation of alkylsilanes
The alkylation of E2 with olefins such as propene, 1-butene, cis-2-butene, isobutene, 1,3-butadiene and methylacetylene smoothly took place over an SO_3/ZrO_2 catalyst which is known as a solid superacid. n-Alkylated products were the main products and the iso-alkylated ones were the minor products regardless the type of olefins used. This suggests that the reaction takes place via nucleophilic attack of olefins on a silicocation.It is interesting finding that the product distribution is basically the same as that of the hydrosilylation catalyzed by transition metal complexes.
These result is a first finding of the heterogeneous catalytic conversion of organosilicone compounds in the world. Less
Research Output (1results)