New approach towards the synthesis of asymmetric heterogeneous catalysts for hydrogenation reactions

VIRGINIA VETERE; MARÍA B. FARAONI; GERARDO F. SANTORI; JULIO C. PODESTÁ; MÓNICA L. CASELLA; OSMAR A. FERRETTI

JOURNAL OF CATALYSIS

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2004 vol. 226 p. 457 - 461

0021-9517

A new type of asymmetric heterogeneous catalysts is presented, together with results obtained in the enantioselective hydrogenation ofethyl pyruvate and acetophenone. The catalysts are prepared by using techniques derived from the surface organometallic chemistry onmetals (reaction between a supported and a reduced transition metal catalyst with an organometallic compound). In the hydrogenation of acetophenone employing Pt-based catalysts, the presence of the organotin promoter notably enhances the chemoselectivity to phenylethanol (the desired product) in all cases. The enantioselective hydrogenation of acetophenone afforded an excess of the (S)-phenylethanol, with an enantiomeric excess (ee%) value of around 20% and a selectivity over 97%. Reusing of the catalysts is possible, keeping the selectivity and the ee% values.