Potassium Yttrium Ate Complexes: Synergistic Effect Enabled Reversible H-2 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 (KR)(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 H-2 activation process. Using this process involving formal addition and elimination of H-2, we accomplished the catalytic hydrogenation of alkenes, alkynes, and imines.