Crucial parameters in the selective triphasic hydrogenation of cinnamaldehyde by biphasic Ru-TPPTS and RhCl(TPPTS)3 catalysts

摘要

A number of important features in the selective hydrogenation of CALD by biphasic Ru-TPPTS catalysts (TPPTS = tris(m-sulfonatophenyl) phosphine trisodium salt) are discussed.These include the methods of synthesis of water-soluble Ru-TPPTS catalysts,the influence of pH during the synthesis and the hydrogenation reaction conditions (the concentration of catalysts,excess amounts of TPPTS,mass transfer characteristics).The Ru-TPPTS catalyst is not only selective at C=O bonds (which is generally known) but also at C=C bonds if certain parameters are controlled carefully.Ninety-six percentage selectivity to unsaturated alcohol and 97% selectivity to saturated aldehyde were achieved under optimum conditions.Some characteristics of the biphasic hydrogenation by RhCl(TPPTS)3 catalyst are also mentioned and compared,particularly those promoting the high selectivity to saturated aldehyde.