Selective hydrogenation of cinnamaldehyde and phospholipids in aqueous-organic biphasic systems with ruthenium(II) complex catalysts

Abstract

Abstract The new water-soluble complex [RuH(OOc)(mtppms)3] (OOc=octanoate, mtppms=monosulfonated triphenylphosphine) was synthesized and – together with the known [RuH(OAc)(mtppms)3] (OAc=acetate) – applied for aqueous-organic biphasic hydrogenation of cinnamaldehyde as well as for hydrogenation of soybean liposomes under mild conditions. The complexes showed pronounced selectivity (up to 75%) towards the hydrogenation of the C=O function in the α,β-unsaturated aldehyde; the selectivity was influenced by the pH of the aqueous phase and the hydrogen pressure. The C=C double bonds in soybean lecithin were only slowly reduced, however, at 5 bar H2 pressure the reaction rate was sufficient to achieve substantial conversion (approximately 20% of all double bonds) in the unsaturated fatty acids.