Catalysis Letters, Vol.83, No.1-2, 55-58, 2002
New "ship-in-a-bottle" type rhodium complexes as efficient catalysts for the hydrogenation of alkenes
A new method for the encapsulation of homogeneous Rh complexes was developed and applied for the heterogenization of [Rh(COD)L](+) complexes, where L = L-prolinamide or N-tert-butyl-L-prolinamide. The "ship-in-a-bottle" type catalysts were prepared by the intrazeolite synthesis method. The heterogenized catalysts were characterized by the usual spectroscopic methods and they have higher specific activity values in the hydrogenation of several different alkenes than the homogeneous counterparts. In the enantioselective hydrogenation of the (Z)-methyl-(2-acetamido-3-phenylacrylate) the ee values were much higher on the heterogenized catalyst than on the homogeneous one.
Keywords:ship-in-a-bottle;enantioselective hydrogenation;heterogenized catalysts;rhodium complexes;prolinamide;zeolite Y