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Study of Catalytic Conversion of Organosilicon Compounds

有机硅化合物催化转化研究

基本信息

批准号：
09450298
负责人：
YAMAGUCHI Tsutomu
金额：
$ 9.09万
依托单位：
Ehima University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1997
资助国家：
日本
起止时间：
1997 至 1999
项目状态：
已结题

项目摘要

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 activation process and the catalytic conversion of alkylsilanes were examined.1. On the initiation step of alkylsilane activation as a model of hydrocarbon activationCatalytic conversion of hydrocarbons in superacidic media is initiated by proton addition yielding a 3c-2e or 5-coordinated intermediate, which decomposes to carbenium ion and hydrogen or alkanes such as methane. NMR and XPS have directly evidenced the existences of such intermediates and the following process. On solid surface like solid acid, it is hard to obtain them since superacidic solid acid is rare to activate saturated hydrocarbons under mild condition. Si-H in organosilane is more active than C-H bond in alkane … More s. Thus We examined the initiation step of alkylsilanes from the hydrogen evolution and the HD content when the silane was contact With deuterated solid acid. As a result, we found (1) hydrogen evolution occurs around room temperature, (2) amount of hydrogen molecule was in the order of μmol g-1, and (3) there are two types of hydrogen evolution process, one is ionic and the other is non- ionic.2. Catalytic hydrosilylation of aliphatic ketonesTitle reaction was examined by using triethylsilane (E3) and diethylsilane (E2) with diethylketone and cyclohexanone at room temperature in a glass batch type reactor. The catalyst was CaO and Al2O3. We obtained silylether from E2 and ketones as a single product in 70-90 % yield after 20-40 h reaction. By-products were the products of aldol condensation of ketone itself. By decreasing the E2/ketone ratio, the yield decreased which indicates a strong interaction of ketones with the catalyst surface. E3 was totally inactive, probably because of the steric hindrance on solid surface.These results are the first finding of the heterogeneous catalytic conversion of organosilicone compounds in the world. Less

在实验室和工业中，有机硅烷的反应通常是在均相液体中使用金属卤化物和过渡金属络合物进行的。硅化合物基础化学在多相催化中的发展是非常吸引人的，也是一个重要的挑战。因此，考察了烷基硅烷的活化过程和催化转化。在烷基硅烷活化的起始步骤中，烃类在超酸介质中的催化转化是通过产生3c-2e或5配位中间体的质子加成引发的，该中间体分解为卡宾离子和氢或烷烃，如甲烷。核磁共振和XPS已经直接证明了这种中间体的存在和随后的过程。在固体表面，如固体酸，很难得到它们，因为在温和的条件下，超酸性固体酸很少活化饱和烃。有机硅烷中的Si-H键比烷烃…中的C-H键更活跃S。因此，我们从硅烷与氚固体酸接触时的析氢和HD含量两个方面考察了烷基硅烷的引发步骤。结果发现：(1)氢的析出发生在室温附近，(2)氢分子的量约为μ摩尔·g~(-1)，(3)有两种析氢过程，一种是离子的，另一种是非离子的。在玻璃间歇式反应器中，考察了三乙基硅烷(E3)和二乙基硅烷(E2)与二乙基酮和环己酮的催化硅氢加成反应。催化剂为CaO和Al_2O_3。反应20-40h后，以酮为原料，以70-90%的产率得到硅醚。副产物是酮本身的羟醛缩合产物。随着E2/酮比的降低，产率下降，这表明酮与催化剂表面有较强的相互作用。E3完全失活，可能是由于固体表面的空间位阻，这是世界上首次发现有机硅化合物的多相催化转化。较少