Transition-metal-catalyzed regeneration of nicotinamide coenzymes with hydrogen

The nicotinamide coenzymes consumed in alcohol dehydrogenase catalyzed enantioselective reduction of ketones are expensive and thus require recycling. We have demonstrated that ruthenium(II) and rhodium(III) complexes are effective catalysts for the reduction of nicotinamide coenzymes with hydrogen, under conditions that are appropriate for in situ coupling with enzymatic reductions.