Room-temperature Ru(II)-catalyzed transfer hydrogenation of ketones and aldehydes in air

Transfer hydrogenation (TH) of ketones and aldehydes was efficiently carried out in 2-propanol at room temperature by means of a ruthenium(II) complex catalyst bearing a 2-(benzoimidazol-2-yl)-6-(pyrazol-1-yl)pyridine ligand. TH of the ketone substrates proceeded in air, reaching final TOFs of up to 59,400 h(-1), and the reduction of aldehydes proceeded under a nitrogen atmosphere to achieve final TOFs of up to 5940 h(-1). (C) 2009 Elsevier Ltd. All rights reserved.