Selective hydrogenations on heterogenized ruthenium complexes

The heterogenized versions of [RuCl2(PPh3)3] and [{RuCl2(TPPMS)2}2] were prepared and applied in the selective hydrogenation of image-unsaturated aldehydes. Depending on the conditions the above heterogenized catalysts could hydrogenate selectively either the Cdouble bond; length as m-dashO or the Cdouble bond; length as m-dashC bonds, similar to the results obtained in aqueous biphasic systems. Meanwhile the heterogenized catalysts show all the advantages that we can expect from a heterogeneous catalyst: good performance, easy separation, and the possibility of recycling. The effect of H2 pressure on the selectivity was also studied.