Ruthenium(II) Terdentate CNN Complexes:Superlative Catalysts for the Hydrogen-Transfer Reduction of Ketones by Reversible Insertion of a Carbonyl Group into the Ru-H Bond

摘要

Pincer ECE (E = N,P) transition-metal complexes,in which the terdentate ligands contain two stable five-membered cyclometalated rings,have reached a high level of sophistication and appear extremely attractive for both catalytic and stoichiometric reactions.The great interest in pincer ligands arises from the high level of control over the reactivity and the stereochemistry that they impose around the metal center as a result of their electronic properties and geometric restrictions.