New Chemistry of Phosphatrane Bases and of Disilanes

爱荷华州立大学化学系John Verkade教授得到化学系无机、生物无机和有机金属计划的支持，从事自由基硅化学的研究和磷环反应性的二次研究。热形成的硅烷自由基将作为炔环三聚反应生成芳香族分子的试剂。将对一系列炔烃进行研究，以确定环三聚过程所能容忍的取代基大小和电子性质的范围。将评估在芳香族产品中加入两种不同的炔烃以及使用各种二硅烷和其他14族化合物的可能性。一系列二硅环体系将由二硅烷与化学计量比的炔烃反应形成，并将用于制备氧桥联的二硅环己二烯聚合物。这项研究的一小部分将针对手性和新型磷杂环“超碱”的合成。炔烃三聚反应是一种非常有用的转化方法，可以将乙炔转化为芳香族分子。最简单的例子是乙炔环化成苯。由于复杂的芳香族分子在自然界中广泛存在，并在许多药物中遇到，因此制备它们的新方法是非常重要的。这项研究将针对一类可以促进三聚的硅化合物。还将制备一组含有两个硅原子的环状分子。这些将被用作形成新聚合物的前体，这些聚合物将比它们类似的有机硅聚合物更坚固。

Professor John Verkade, Chemistry Department, Iowa State University is supported by the Inorganic, Bioinorganic, and Organometallic Program of the Chemistry Division for investigations into free radical silicon chemistry and secondary studies of the phosphatrane reactivity. Thermally formed silane free-radicals will be reagents for the formation of aromatic molecules by alkyne cyclotrimerization. A range of alkynes will be investigated to define the range in substituent size and electronic properties that the cyclotrimerization process can tolerate. The possibility of incorporating two different alkynes into the aromatic product and of using various disilanes and other group 14 cogners will be evaluated. A series of disilicon ring systems will be formed by reactions of disilanes with stoichiometric amounts of alkynes and will be used to produce oxygen bridged disilcyclohexandiene polymers. A minor portion of the investigation will target the synthesis of chiral and novel phosphatrane "superbases." Alkyne trimerization is an extremely useful transformation that converts acetylenes into aromatic molecules. The simplest example is the cyclization of acetylene to benzene. Since complex aromatic molecules are found throughout nature and are encountered in many, e.g., pharmaceuticals, new methods for preparing them are very significant. This study will target a class of silicon compounds that can facilitate the trimerization. A set of cyclic molecules that contain two silicon atoms will also be prepared. These will be used as precursors to form new polymers that will be more robust than the silicone polymers, which they resemble.