Synthesis of Kinetically Stabilized 1‐Silanaphthalenes and Their Properties.
Synthesis of Kinetically Stabilized 1‐Silanaphthalenes and Their Properties.
复制标题
动力学稳定的 1-硅萘的合成及其性能。
DOI：
10.1002/chin.200542189
复制
发表时间：
2005
期刊：
影响因子：
--
通讯作者：
N. Tokitoh
中科院分区：
文献类型：
--
作者：
A. Shinohara;N. Takeda;T. Sasamori;N. Tokitoh
以拥挤型溴硅烷为原料，在四氢呋喃中用二异丙胺脱氢溴化，在2，6-bis[bis(trimethylsilyl)methyl]-4-[tris(trimethylsilyl)methyl]phenyl 40°C下，合成了第一批具有2，4，6-三[二(三甲基硅基)甲基]苯基或−(Bbt)基团的动力学稳定的1-硅代萘。通过~1H、~(13)C和~(29)Si核磁共振谱、紫外-可见光谱、拉曼光谱和高分辨质谱分析确证了它们的结构。这些结果和NICS计算表明，1-硅萘具有很高的芳香性。尽管有如此高的芳香度，但TBT取代的1-硅萘是热不稳定的，在C6D6溶液中经历逐步二聚，得到相应的[4+2]二聚体。相反，硅原子上带有BBT基团的1-硅萘在120℃的C6D6中加热时仍是热稳定的，TBT取代的1-硅萘对1，2-和1，4-位的加成反应都有很高的反应活性，在与水、甲醇、氧化甲腈、二苯甲酮和元素硫的反应中生成了相应的加合物。TBT取代的1-硅萘与CCl4发生1，4-加成反应，得到硅原子上有一个氯原子，4-位上有一个CCl3基团的顺式和反式加合物。
The first kinetically stabilized 1-silanaphthalenes bearing a 2,4,6-tris[bis(trimethylsilyl)methyl]phenyl (Tbt) group or a 2,6-bis[bis(trimethylsilyl)methyl]-4-[tris(trimethylsilyl)methyl]phenyl (Bbt) group were synthesized from the corresponding overcrowded bromosilanes by dehydrobromination using LDA (lithium diisopropylamide) in THF at −40 °C, respectively. The structures of 1-silanaphthalenes were confirmed by1H,13C, and29Si NMR, UV–vis, Raman, and high-resolution mass spectroscopic analyses. These results and the NICS calculations indicated high aromaticity of the 1-silanaphthalenes. In spite of such high aromaticity, Tbt-substituted 1-silanaphthalene is thermally unstable and undergoes gradual dimerization in C6D6solution to give the corresponding [4 + 2] dimer. By contrast, 1-silanaphthalene bearing a Bbt group on the Si atom was thermally stable even on heating in C6D6at 120 °C. Tbt-substituted 1-silanaphthalene has high reactivity toward addition reactions at both 1,2- and 1,4-positions, giving the corresponding adducts in the reactions with H2O, MeOH, mesitonitrile oxide, benzophenone, and elemental chalcogens. Tbt-substituted 1-silanaphthalene underwent 1,4-addition reaction with CCl4to give cis- and trans-adducts having a Cl atom on the Si atom and a CCl3group at the 4-position.