Challenge to Expand the Concept ofAromaticity to Tin- and Lead-containingCarbocyclic Compounds: Synthesis, Structures and Reactions of Dilithiostannoles and Dilithioplumbole
Challenge to Expand the Concept ofAromaticity to Tin- and Lead-containingCarbocyclic Compounds: Synthesis, Structures and Reactions of Dilithiostannoles and Dilithioplumbole
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将芳香性概念扩展到含锡和铅碳环化合物的挑战：二锂硫锡烷醇和二锂铅铅的合成、结构和反应
DOI：
10.1016/j.ccr.2011.10.020
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发表时间：
2012
期刊：
影响因子：
--
通讯作者：
M. Saito
中科院分区：
文献类型：
--
作者：
本田康;清野淳司;染野秀介;波田雅彦;T. Ueba;M. Saito
芳香族化合物长期以来在有机化学中发挥着重要的作用。大多数芳香族化合物的骨架主要由碳原子和其他第二行元素组成。然而，最近的一个问题是，当π-骨架的碳原子被更重的14族原子取代时，芳香性的概念是否可以应用。与最近大量的关于创造含硅和锗的碳环π-框架的工作相反，这些工作证明了新的较重的芳香族化合物，2001年没有人知道芳香性的概念是否可以应用于含锡的碳环化合物。因此，我们的目标是合成一种硫代锡醇，这是一种锡阴离子的锡类似物。通过还原相应的1，1-二苯基衍生物，成功地合成了二锂锡醇及其苯并环化衍生物。X-射线衍射分析表明，每个锡醇环几乎是平面的，没有C-C键的键交替。根据它们的结构特征和在环上1.0 <$m处计算的非常负的非核依赖化学位移（NICS）值，推断它们是第一个含锡碳环芳香化合物。在benzannulated衍生物中，每个甲锡醇环比其相邻的苯环更具芳香性，如通过理论计算所确定的。并合成了硫代铅茂，X-射线衍射分析和理论计算表明，硫代铅茂具有较好的芳香性。因此，芳香性的概念现在扩展到含铅的碳环化合物。还证明了硫代锡醇和铅醇的反应性。
The aromatic compounds have for a long time played important roles in organic chemistry. The skeletons of most aromatic compounds consist mainly of carbon atoms and other second-row elements. However, a recent question is whether the concept of aromaticity can be applied when the carbon atoms of the π-frameworks are substituted by heavier group 14 atoms. In contrast to recent extensive works on the creation of silicon- and germanium-containing carbocyclic π-frameworks, which demonstrated novel heavier aromatic compounds, no one knew whether or not the concept of aromaticity could be applied to tin-containing carbocyclic compounds in 2001. We therefore targeted the synthesis of a dilithiostannole, which is a tin-analog of the cyclopentadienyl anion. Dilithiostannoles and its benzannulated derivatives were successfully synthesized by reduction of the corresponding 1,1-diphenyl derivatives. X-ray diffraction analysis of the dilithiostannoles revealed that each of the stannole rings is almost planar without bond alternation of the C–C bonds. Based on their structural features and very negative nucleus-independent chemical shift (NICS) values calculated at 1.0Å above the rings, the dilithiostannoles were concluded to be the first tin-containing carbocyclic aromatic compounds. In the benzannulated derivatives, each of the stannole rings is more aromatic than its adjacent benzene ring, as determined by theoretical calculations. The synthesis of dilithioplumbole was also accomplished and it was concluded to have considerable aromatic character, as supported by X-ray diffraction analysis and theoretical calculations. Therefore, the concept of aromaticity is now extended to lead-containing carbocyclic compounds. The reactivity of the dilithio-stannoles and -plumbole is also demonstrated.