Synthesis of Al(I)-based Frustrated Lewis Pairs and Reactivity in Activation of Small Nitrogen-containing Molecules

介绍了新型Al(I)化合物及其衍生受阻Lewis对(FLP)的合成，并将其应用于小分子活化。特别是它们对作为氮素同系物的含氮小分子的行为将会引起人们的兴趣。在这里，通过捕获受挫的Lewis对之间的各自底物，从而促进NN键的断裂和其他小分子的攻击，空间要求很高的Lewis酸的帮助是关键的，以创造一个协同的推拉环境。电子缺乏Al(I)中心的稳定是通过引入具有大量空间需求的单阴离子多齿配体(双齿Y∩L和钳形Y∩L2，Y=阴离子给体，L=中性给体)来实现的，而电子稳定是通过强给体部分实现的。通过仔细调整配体系统的空间体积以及给体和受体的性质，可以预期Al(I)中心的不同反应活性。这种高活性和路易斯碱性或双亲的化合物被推定为表现出前所未有的和吸引人的新反应活性。

The synthesis of novel Al(I) compounds and derived frustrated Lewis pairs (FLP) is addressed with the ultimate goal to apply them in small molecule activation. Especially their behaviour towards small nitrogen-containing molecules acting as dinitrogen congeners will be of interest. Here, the aid of sterically demanding Lewis acids to create a synergistic push-pull environment by capturing the respective substrate in between the frustrated Lewis pair, thereby facilitating NN bond scissions and attacks of other small molecules is crucial. Stabilization of the electron deficient Al(I) centers is tackled by the introduction of monoanionic multidentate (bidentate Y∩L and pincer Y∩L2, Y = anionic donor, L = neutral donor) ligands with substantial steric demand to provide kinetic stabilization, whereas electronic stabilization is implemented by strong donor moieties. By careful tuning of the ligand system in terms of steric bulk, as well as donor and acceptor properties, different reactivities of the Al(I) center are expected. Such highly reactive and Lewis basic or ambiphilic compounds are presumed to show unprecedented and fascinating new reactivities.