以組裝方式合成多芽氮異環碳烯

Abstract

橋接形式的高對稱性多牙氮異環碳烯具有多個可獨立作用的反應區域，因此被認為具有相當大的潛力被應用於延伸性的分子材料之中。然而，由於其合成路徑相當複雜及起始物成本相對比較高的緣故，若要有進一步的應用有相當的困難性。為了克服在合成上的困難，在我們的研究中，我們藉由組裝的概念來發展能以較低成本且快速的方法來合成有高對稱性的多牙氮異環碳烯。因此，首先我們設計了一個具有雙重功能性的分子(4,6)，這個分子同時具有氮異環碳烯的前驅物咪唑鹽，以及可與氨基反應的鄰苯二甲酸酐。藉由引入有高對稱性骨架的多氨基化合物，我們成功的合成了雙元、三元、四元及六元咪唑鹽(13-20)，並進一步的合成相關的雙核、三核、四核及六核鎳及銠的金屬錯合物(21-27)，以期這些錯合物將來能在有機催化及延伸性材料的建構上能有更進一步的發展。

In recent years, bridging-type poly N-heterocylic carbenes attracted much attention, because each carbene moiety has opportunity to function independently. As a result, they are viewed as potential building blocks in extended materials. However, the reported synthetic routes for highly symmetrical bridging-type poly-NHCs were too complicated to broaden the application of such ligand system. In order to overcome these disadvantages, in this work, we developed a new synthetic strategy for highly symmetrical poly-NHCs using the assembly method. To this end, we designed and synthesized a bifunctional molecular building unit (4, 6) consisting of a carbene precursor and a phthalic anhydride group, which would undergo dehydrative condensation when treated with primary amines. By introducing different polyamino compounds, we can easily construct various poly-imidazolium salts (13-20). We also used these newly synthesized poly-NHCs to form the corresponding multi-nuclear metal complexes (21-29), which should find further applications in heterogeneous catalysis.