Studies on Synthetic Utilities, Properties, and Functionalities of Novel Acylsilanes

为了了解酰基聚硅烷的合成效用，制备了三种新型酰基聚硅烷，并研究了它们的热异构化，发现它们可能是线性共轭硅烷的有用前体，如下所述。此外，发现由酰基聚硅烷制备的硅烯醇化物与二苯甲酮的反应容易地以良好的产率产生二氧杂硅杂环戊烷衍生物。这些结果清楚地表明，酰基聚硅烷可用于制备新型的硅活性物种以及环状有机硅化合物。1）发现硅烯醇锂与苯基取代的乙炔反应得到酰基-（Z）-乙烯基二硅烷，这是α-官能化酰基聚硅烷的第一个例子。由此获得的酰基乙烯基二硅烷在>100 ℃下经由2-硅杂二烯中间体进行独特的异构化。这似乎是一种在相当低的温度下生产硅杂二烯的重要方法。2）研究了涉及2，3-二硅杂二烯中间体的双（酰基）二硅烷的热异构化，导致形成1，2-二硅杂环丁烯衍生物。3）具有通过环烷烃桥连接的两个酰基的化合物在>120 ℃下发生热异构化，得到相应的扩环产物。这是首次观察到的oxa-Cope重排的硅烯。

To know the synthetic utilities of acylpolysilanes, three novel types of acylpolysilanes were prepared and their thermal isomerization was studied and found that they may be useful precursors for linear conjugated silenes, as summarized bellow. In addition, it was found that the reactions of silaenolates prepared from acylpolysilanes with benzophenone readily produced dioxasilacyclopentane derivatives in good yields. These results clearly indicate that the acylpolysilanes are useful for the preparation of novel silicon reactive species as well as that of cyclic organosilicon compounds.1) It was found that the reactions of lithium silaenolates with phenyl-substituted acetylenes afforded acyl-(Z)-ethenyldisilane as the first example of α-functionalized acylpolysilanes. Acylethenyldisilanes thus obtained underwent unique isomerization at >100 degree C via 2-siladiene intermediates. This appears to be an important methodology to produce siladiene at rather low temperature.2) Thermal isomerization of a bis(acyl)disilane involving a 2,3-disiladiene intermediate, leading to the formation of a 1,2-disilacyclobuene derivative was investigated3) Thermal isomerization of compounds having two acyl groups linked by a cycloalkane bridge took place at >120 degree C to give the respective ring-enlarged products. This is the first observation of oxa-Cope rearrangement of silenes.