Aromatic Compounds Consisting of Heavier Group 14 Elements

由较重的第 14 族元素组成的芳香族化合物

• 批准号: 10304051
• 负责人: SEKIGUCHI Akira
• 金额: $ 20.03万
• 依托单位: University of Tsukuba
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (A).
• 财政年份: 1998
• 资助国家: 日本
• 起止时间: 1998 至 2000
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10304051/
• 关键词: Heavier Group 14 Element; Organosilicon Compound; Organogermane Compound; Unsaturated Small Ring Compound; Cyclotrisilene; Disilagermirene; Homoaromaticity; Cyclotetrasilenylium Ion; シクロトリシレン; 芳香族化合物; シクロトリゲルメニウムイオン; シクロトリゲルメン; ゲルミルカチオン; 酸化的結

The chemistry of aromatic compound consisting of heavier Group 14 elements has been remarkably developed. In 1997, we prepared tris (tri-tert-butylsilyl) cyclotrigermenyium ion [(^tBu_3SiGe)_3^+], which is the first example of a 2π aromatic system consisting of germanium atoms as well as a free germyl cation. In this research project, we have established the preparation of heavier analog of cyclopropene and also investigated its transformation to aromatic compounds consisting of heavier Group 14 elements.1. The reductive coupling of ^tBu_2MeSi-substituted-dibromosilane and-tribromosilane gave tetrakis [di-tert-butyl (methyl) silyl] cyclotrisilene (1) with an unsaturated three membered ring structure consisting of silicon. The reaction of cyclotrisilene (1) with [Et_3Si (benzene)]^+ TPFPB^-[TPFPB^-=(C_6F_5)_4B^-] produced 1, 2, 3-tris [di-tert-butyl (methyl) silyl]-4, 4-di-tert-butylcyclotetrasilenium TPFPB^-(2^+ TPFPB^-), which can be isolated as yellow crystals. The crystallographic analysis as well as NMR study reveal that cyclotetrasilenium ion (2^+) is a "free" silyl cation with a homoaromatic 2π-electron system in the condensed phase.2. Cyclotetrasilenium ion (2^+) was found to undergo stepwise reduction to give cyclotetrasilenyl radical (2^< >) by one electron reduction and cyclotetrasilenide ion (2^-) by two electron reduction, respectively. We succeeded in synthesizing red crystals of cyclotetrasilenyl radical (2^< >) as the first isolable silyl radical with an allyl type delocalized structure.3. We have also succeeded in synthesizing tetrakis [di-tert-butyl (methyl) silyl]-1-disilagermirene (3) with a Si=Si double bond, which is thermally or photochemically isomerized to tetrakis [di-tert-butyl (methyl) silyl]-2-disilagermirene (4) with a Si=Ge double bond. 2-Disilagermirene (4) reacted with phenylacetylene to give 3-germa-1, 2-disilacyclopent-2, 4-diene derivative (5) with a Si=Ge-C=C conjugated system.

由较重的14族元素组成的芳香族化合物的化学已经得到了异常发展。1997年，我们制备了三(三叔丁基甲硅烷基)环三锗离子[(^tBu_3SiGe)_3^+]，这是第一个2π芳香族化合物的例子。由锗原子和游离甲阳离子组成的体系在这个研究项目中，我们已经建立了环丙烯的重类似物的制备方法。研究了其向由较重的第 14 族元素组成的芳香族化合物的转化。 ^tBu_2MeSi 取代的二溴硅烷和三溴硅烷的还原偶联得到四[二叔丁基（甲基）甲硅烷基]环三硅烯（1）与不饱和三元化合物。环三硅烯 (1) 与 [Et_3Si (苯)]^+ 的反应。 TFPPB^-[TPFPB^-=(C_6F_5)_4B^-] 生成 1, 2, 3-tris [二叔丁基（甲基）甲硅烷基]-4, 4-二叔丁基环四硅鎓 TFPPB^-(2^ + TPFPB^-)，可以以黄色晶体形式分离出来。晶体学分析和 NMR 研究表明，环四硅。离子(2^+)是在凝聚相中具有同芳香族2π-电子系统的“游离”硅基阳离子。2.发现环四硅离子(2^+)经历逐步还原以产生环四硅基自由基(2^< >)。通过一个电子还原和环四硅化物离子（2^-）通过两个电子还原，我们分别成功合成了红色晶体。环四硅烯基(2^< >)是第一个具有烯丙基型离域结构的可分离硅基。3． Si=Si双键，热或光化学异构化为四[二叔丁基（甲基）具有Si=Ge双键的甲硅烷基]-2-二硅杂环戊烯(4) 2-二硅杂环戊烯(4)与苯乙炔反应，得到具有Si的3-germa-1,2-二硅杂环戊烯-2,4-二烯衍生物(5)。 =Ge-C=C共轭体系。