Potassium Yttrium Ate Complexes: Synergistic Effect Enabled Reversible H2 Activation and Catalytic Hydrogenation

A potassium yttrium benzyl ate complex was generated simply by mixing an yttrium amide and potassium benzyl. The benzyl ate complex could undergo peripheral deprotonation to produce a cyclometalated complex or hydrogenation to give a hydride ate complex. The latter hydride ate complex features a (KH)2 structure protected by two yttrium amide complexes. The synergistic effect between potassium hydride and the amide ligand enables the complex to deprotonate a methyl C–H bond. The combination of intramolecular deprotonation of the hydride ate complex and hydrogenation of the cyclometalated complex constitutes a reversible H2 activation process. Using this process involving formal addition and elimination of H2, we accomplished the catalytic hydrogenation of alkenes, alkynes, and imines.

通过将钇酰胺与苄基钾简单混合，可合成钾钇苄基酸根络合物（potassium yttrium benzyl ate complex）。该苄基酸根络合物可发生外围去质子化反应生成环金属化络合物（cyclometalated complex），或经氢化反应得到氢化物酸根络合物（hydride ate complex）。该氢化物酸根络合物具有由两个钇酰胺络合物保护的(KH)₂二聚结构。氢化钾（potassium hydride）与酰胺配体（amide ligand）间的协同效应，使该络合物可对甲基C-H键实现去质子化。氢化物酸根络合物的分子内去质子化与环金属化络合物的氢化反应相结合，构成了可逆氢气活化过程（reversible H₂ activation process）。借助这一涉及氢气形式加成与消除的过程，我们成功实现了烯烃（alkenes）、炔烃（alkynes）以及亚胺（imines）的催化氢化反应。