Chiral-at-Metal Ruthenium Complex as a Metalloligand for Asymmetric Catalysis

The mononuclear [Ru(bpy)(2)(bpym)][PF(6)](2) complex (bpy = 2,2'-bipyridine; bpym = 2,2'-bipyrimidine) has been prepared in its enantiopure Lambda form. Because of the chelating property of the bipyrimidine moiety, it is possible to use this chiral-at-metal complex as a chiral inorganic ligand for a second metal cation acting as a catalytic center. Here we report the synthesis and the structural characterization of a novel dinuclear Lambda-[(bpy)(2)Ru(bpym)RuCl(p-cymene)](3+) compound (1). The asymmetric-inducing properties of the enantiopure chiral-at-metal metalloligand have been probed during asymmetric transfer hydrogenation to ketones catalyzed by 1. This provides one of the very few illustrations of the potential of this original class of chiral inorganic ligands.