Journal of Molecular Catalysis A-Chemical, Vol.189, No.2, 219-224, 2002
Enantioselective hydrogenation of ethyl pyruvate catalyzed by polyvinylpyrrolidone-stabilized and supported rhodium nanocluster
The enantioselective hydrogenation of ethyl pyruvate catalyzed by finely dispersed oxide supported rhodium nanocluster was studied with cinchonidine as chiral modifier. The results indicated that cinchonidine not only exhibited good enantiodifferentiating ability but also could accelerate the reaction by a factor 10. Supports (gamma-Al2O3, SiO2, TiO2) played an important role in promoting the further increase of catalytic activity and enantioselectivity of polyvinylpyrrolidone-stabilized rhodium nanoclusters (Rh/PVP). Under the optimum reaction conditions (298 K, 7.0 MPa of hydrogen pressure and tetrahydrofuran as solvent), TOF and the enantiomeric excess reached 58.6 min(-1) and 65.4% e.e., respectively. (C) 2002 Elsevier Science B.V. All rights reserved.