碳硼烷支撑的氮杂环卡宾及其主族元素类似物

Continuous focus on carboranes is stimulated by their rich coordination chemistry and promising special applications. On the other hand, N-hetercyclic carbenes (NHCs) and their transition-metal complexes are of great interest in modern organometallic chemistry. Main group element carbene anologues have also been widely investigated. However, there are few reports about the syntheses and/or applications of NHCs and its main group element anologues bearing o-carborane ligands. Carboranes have special three-dimensions pseudo-aromatic system, good chemical and thermal stability. Its complexes have good solubility and are easy to crystallize. The introduction of carborane to NHCs would largely change their electronic effects; enhance the coordination ability and the reactivity of the catalysts. Based on this, this project will design a newly functionalized carborane, the di(imine) carborane, which would be used to construct the N-hetercyclic carbenes and its main group element carbene anologues. The transition-metal NHC complexes and their catalytic ability, small molecular activity ultlizing the carbene anologues, multiple bonding compounds between heavier main group elements would also been investigated in this project. The steric and electronic effect of the o-carborane would be analyzed eventually.

碳硼烷及其衍生物由于具有配位化学的丰富性、功能的独特性，而成为化学家们关注的焦点。另一方面，氮杂环卡宾及其金属配合物则是现代有机金属化学中最热门的课题之一，其主族元素类似物也被广泛研究。但将官能化碳硼烷用于氮杂环卡宾及其主族元素类似物的合成及应用方面却鲜有报道。碳硼烷具有良好的化学稳定性和热稳定性，其配合物具有溶解性好、易于结晶等优点，除此之外，碳硼烷还具有性质迥异的三维类芳香结构。将碳硼烷引入氮杂环卡宾将大大改变它们的电子效应，增强其配位能力及催化剂反应活性。本项目拟设计一类新型的官能化碳硼烷—二胺基碳硼烷，并合成碳硼烷支撑的氮杂环卡宾及其主族元素类似物。研究这些碳硼烷并氮杂环卡宾的过渡金属配合物及其催化性能，研究卡宾类似物在小分子活化、形成重主族元素多重键等方面的能力。考查碳硼烷电子效应的影响，筛选出一批具有优异性能的碳硼烷衍生物，为碳硼烷的实际和潜在应用提供方向并奠定基础。

碳硼烷及其衍生物由于具有配位化学的丰富性、功能的独特性，而成为化学家们关注的焦点。另一方面，氮杂环卡宾及其金属配合物则是现代有机金属化学中最热门的课题之一，其主族元素类似物也被广泛研究。但将官能化碳硼烷用于氮杂环卡宾及其主族元素类似物的合成及应用方面却鲜有报道。碳硼烷具有良好的化学稳定性和热稳定性，其配合物具有溶解性好、易于结晶等优点，除此之外，碳硼烷还具有性质迥异的三维类芳香结构。本项目在以下几个方面开展了工作：i）设计并合成了一类新型的官能化碳硼烷—二氨基碳硼烷，发现在其衍生物中，具有超长的C-C单键，其原因为“面内的负超共轭效应”；ii）将碳硼烷和氮杂环卡宾结合起来，设计合成了新型的氮杂环卡宾前体及其过渡金属配合物；iii）设计合成了新型的卡宾类似物-锡烯。研究了一些卡宾类似物（锗烯、锡烯）与小分子的反应；iv）设计并合成了一系列碳硼烷支撑的salen配体及其相关金属配合物，并研究了其在均相催化中的应用，筛选出了几例有优秀催化活性的催化剂。以上研究，为碳硼烷的实际和潜在应用提供方向并奠定基础，拓展了碳硼烷化学的研究范畴。