研究室工作進展 Jun. 10th, 2014
Cyclopentadienyl-Like Ligand as a Reactive Site in Half-Sandwich Bis(amidinato) Rare-Earth-Metal Complexes: An Efficient Application in Catalytic Addition of Amines to Carbodiimides
Peng-Hui Wei, Ling Xu, Li-Cheng Song,* Wen-Xiong Zhang,* and Zhenfeng Xi*
Organometallics 2014, 33, 2784−2789.
A series of mixed Cp′/bis(amidinato) (Cp′ = η5-C5Me4(SiMe3)) lanthanide complexes were synthesized by the 1:2 acid−base reaction between Cp′Ln(CH2SiMe3)2(THF) (Ln = Y, Dy, Er, Lu) and amidines. These Cp′/bis(amidinato) complexes showed excellent catalytic activity for the addition of amines to carbodiimides, yielding the corresponding guanidines. Isolation, structural characterization, and catalytic application of the binuclear lutetium amido complex showed clearly that the catalytic cycle was initiated by the dissociation of Cp′. These results demonstrated that Cp′, for the ?rst time, acted as a reactive site to yield the active Ln−N species.
亮點介紹
環戊二烯（Cp）和脒是金屬有機化學中兩類非常重要的配體，它們常被用來穩定金屬有機化合物及調控金屬有機化合物的反應活性。因此，設計合成同時含有Cp和脒配體的金屬有機化合物，研究它們對同一金屬有機化合物的穩定能力及反應化學，對新配體和新金屬有機化合物的設計、合成具有重要的意義。我們設計、合成了一系列稀土金屬單茂/雙脒配合物，通過胺與碳二亞胺的成胍反應，研究了該類配合物的催化活性。通過雙核镥氨基化合物的分離、結構表征，研究了該反應機理。結果表明，環戊二烯配體作為活性中心形成Ln−N鍵活性物種，啟動該催化循環。該工作與南開大學宋禮成先生課題組合作完成。