Selective hydrogenation of trans-4-phenyl-3-butene-2-one to unsaturated alcohol over Ru/γ-Al2O3 modified by PPh3 and diamines

The selective hydrogenation of trans-4-phenyl-3-butene-2-one over Ru/γ-Al2O3 stabilized with triphenylphosphine was investigated in the presence of diamine and base. It was found that 1,2-diphenylethylene-1,2-diamine (DPEN) was the best modifier among the investigated diamines. Both DPEN and KOH not only promoted the selectivity of the CO bond hydrogenation, but also accelerated the rate of the hydrogenation. Under the optimum conditions: the reaction temperature of 35 °C, H2 pressure of 4.0 MPa, KOH concentration of 0.04 mol/l, and reaction time of 3 h, the conversion of trans-4-phenyl-3-butene-2-one was close to 100% and the selectivity to unsaturated alcohol was more than 99%. In combining with the effect of reaction factors on the hydrogenation, a possible hydrogenation mechanism is proposed.

Catalyst Ru/γ-Al2O3, which modified by triphenylphosphine and aliphatic and cycloaliphatic diamines, showed a highly catalytic activity and selectivity for the hydrogenation of CO double bond of trans-4-phenyl-3-butene-2-one. The conversion and selectivity of trans-4-phenyl-3-butene-2-one was up to 99% under the optimum reaction conditions.Figure optionsDownload as PowerPoint slide