研究室工作进展 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.
亮点介绍
环戊二烯（Cp）和脒是金属有机化学中两类非常重要的配体，它们常被用来稳定金属有机化合物及调控金属有机化合物的反应活性。因此，设计合成同时含有Cp和脒配体的金属有机化合物，研究它们对同一金属有机化合物的稳定能力及反应化学，对新配体和新金属有机化合物的设计、合成具有重要的意义。我们设计、合成了一系列稀土金属单茂/双脒配合物，通过胺与碳二亚胺的成胍反应，研究了该类配合物的催化活性。通过双核镥氨基化合物的分离、结构表征，研究了该反应机理。结果表明，环戊二烯配体作为活性中心形成Ln−N键活性物种，启动该催化循环。该工作与南开大学宋礼成先生课题组合作完成。