Collect. Czech. Chem. Commun. 1986, 51, 836-841

Silica supported cationic rhodium(I) complexes as hydrogenation catalysts

Vladimír Zbirovský and Martin Čapka

Institute of Chemical Process Fundamentals, Czechoslovak Academy of Sciences, 165 02 Prague 6 - Suchdol


Cationic silica-supported Rh(I) complexes prepared from Rh(COD) (acac) and phosphines of the type (C2H5O)3Si(CH2)nP(C6H5)2 (n = 1,3) in the presence of p-toluenesulphonic acid were found to be efficient catalysts for hydrogenation of alkenes, alkadienes, and Z-α-acetamidocinnamic acid at 40 °C and normal hydrogen pressure. Kinetic measurements showed that the most efficient catalysts are obtained at the P : Rh mol. ratio = 2. When this ratio was ensured for each molecule of the immobilized complex, such catalysts were three to four times more active than their homogeneous analogues.