Enantioselective Hydrogenations of C=O (Carbon-Oxygen Double Bonds) Catalysed by Immobilized Rh Complexes

Using a modified Augustines method different Rh complexes were anchored on Al2O3 support. The prepared catalysts were characterized by usual spectroscopic methods and were applied in the hydrogenation of several acetophenone derivatives (p-CF3-acetophenone, acetophenone, p-NH2-acetophenone). Enantioselective C=O hydroge-nations were observed with reasonable activity and selectivity on all heterogenized complexes, e. e. up to 80 % was observed. Meanwhile the immobilized samples showed all the advantages of the heterogeneous systems easy handling and recyclability.