Development of New Method for Preparation of Heterocycles Using Reactive Intermediates.

众所周知，乙烯基阳离子是一种活性中间体，通过与乙酰键的亲电加成反应而形成。我们还发现，卤化乙烯的光解和溶解会产生乙烯基阳离子。在本研究中，我们研究了通过分子内反应形成杂环，在分子内反应中，乙烯基阳离子在阳离子中心附近含有氧和硫等杂原子。结果表明，生成的环状洋葱离子的环状结构和杂原子的性质对其稳定性和分离效果有重要影响。特别是在硫的情况下，分离出的环硫离子的光谱数据和化学行为表明它是硫烷结构。乙烯基叠氮化物通过卤化乙烯的亲核取代得到的叠氮乙烯在热或光化学上得到氮杂环，它们在热分解过程中发生C-N裂变生成乙烯基硝烯。乙烯基硝烯的电环反应提供5、6和7元杂环。特别是通过氮杂环二聚反应得到的吡嗪类化合物具有液晶性质，被应用于分子组装化学中。制备了各种含杂环的液晶和两亲性化合物。这些化合物形成了单分子膜。在实验和理论结果的基础上，考虑了单分子膜的行为和结构之间的关系。本研究制备的LB膜具有较大的SH强度，已发展成为光学材料。

It is well known that vinyl cations, one of reactive intermediates, are formed by electrophilic addition to acetylenic bonds. We have also found that photolysis and solvolysis of vinyl halides generate vinyl cations. In this study we investigated formation of heterocycles by intramolecular reaction, in which vinyl cations contain heteroatoms such as oxygen and sulfur at the neighboring position to the cationic center. The results indicated the cyclic structure of the resulting cyclic onium ions and the nature of the heteroatom play a significant role in the stability and the isolation. In particular, in the case of sulfur, the spectral data of the isolated cyclic sulphonium ion and the chemical behaviors suggested the sulphurane structure.Vinyl azides obtained by nucleophilic substitution of vinyl halides afford azirines thermally or photochemically, which undergo C-N fission in thermolysis to produce vinyl nitrenes. the electrocyclic reaction of vinyl nitrenes provides 5, 6, and 7-membered heterocycles. Especially, pyrazine derivatives obtained by dimerization of azirines showed the character of liquid crystals and werre applied to chemistry of molecular assembly. Various heterocycle-containing liquid crystals and amphiphilic compounds were prepared. These compounds formed monolayers. The relationship between the behavior and the structure of the monolayers were considered on the empirical and theoretical results. The LB films prepared by this study showed a large SH intensity and were developed to optical materials.