Diruthenium catalyst especially for hydrogen-transfer reactions. Prepn: Y. Blum, Y. Shvo, J. Organomet. Chem. 282, C7 (1985); Y. Shvo et al., J. Am. Chem. Soc. 108, 7400 (1986). X-ray structure study: M. J. Mays et al., Organometallics 8, 1162 (1989). Mechanism of hydrogen transfer: J. B. Johnson, J.-E. B"ackvall, J. Org. Chem. 68, 7681 (2003). Catalytic disproportionation of aldehydes: N. Menashe, Y. Shvo, Organometallics 10, 3885 (1991). Resolution of alcohols: B. A. Persson et al., J. Am. Chem. Soc. 121, 1645 (1999); oxidation of alcohols: J. H. Choi et al., Tetrahedron Lett. 45, 4607 (2004). Brief review: R. Prabhakaran, Synlett 2004, 2048-2049.