Bimetallic synergic effect in the selective catalytic hydrogenation of cinnamaldehyde

The bimetallic catalysts, PdCl2-0.5MY-PPh3 [MY = NiCl2, Ni(OAc)(2), Fe(acac )(3), Co(OAc)(2), Co(acac)(2) or CoCl2] reduced by NaBH4, exhibit much high er selectivity in comparison with that of the monometallic Pa catalyst in t he selective hydrogenation of cinnamaldehyde to 3-phenylpropanal at 66 degr ees C under atmospheric pressure, A strong synergic effect occurs between P d and the second metal component for the high selectivity. Among these cata lysts, PdCl2-0.5Co(OAc)(2)-PPh3 reduced by NaBH4 is the best catalyst.