Synthesis and characterization of tetraosmium clusters containing ferrocenyl based diphosphine ligands as potential catalysts in asymmetric hydrogenation

Abstract: The metal cluster [H4Os4(CO)12] was treated with various chiral ferrocenyl diphosphines of the Walphos family. The new compounds; [H4Os4(CO)10{μ -1,2-W001}], [H4Os4(CO)10{μ -1,2-W002}], [H4Os4(CO)10{μ -1,2-W003}] and [H4Os4(CO)10{μ -1,2-W005}] were characterized, and [H4Os4(CO)10{μ -1,2-W001}] was investigated in its enantioselective catalytic properties in the hydrogenation of tiglic acid. It was demonstrated that the enantioselectivity with this compound is insignificant (6% ee) and that it is not a suitable hydrogenation catalyst at our conditions (31% conversion).