For synthesis of enantiopure ethylenediamines by chirality transfer (condensation with diketones followed by reductive cleavage), see: J. Org. Chem ., 57, 6653 (1992). Co-catalyst in the Ru catalyzed enantioselective hydrogenation of aromatic ketones: J. Am. Chem. Soc., 117, 2675 (1995).