Ruthenium(II) complexes of amine ligands are known for engaging in the outer-sphere mechanism, during which the imine/iminium substrate does not bind to the metal center directly. Instead, substrate receives the elements of H by interaction with Ru-H and N-H sites.  This process is utilized by the Shvo catalyst and many ruthenium amine complexes.  One such complex is Baratta's catalyst RuCl(PPh)(ampy) (ampy = 2-picolylamine) for transfer hydrogenation.