New Type of 2,6-Bis(imidazo[1,2‑a]pyridin-2-yl)pyridine-Based Ruthenium Complexes: Active Catalysts for Transfer Hydrogenation of Ketones

Neutral and cationic ruthenium­(II) complexes bearing a symmetrical 2,6-bis­(imidazo­[1,2-a]­pyridin-2-yl)­pyridine were synthesized and structurally characterized by NMR analysis and X-ray crystallographic determinations. These complexes have exhibited good catalytic activity in the transfer hydrogenation of ketones. In refluxing isopropyl alcohol, the conversion of the substrates reached up to 99%, and a TOF value of 356 400 h^–1 with 0.1 mol % catalyst was achieved.