Homogeneous and heterogeneous ruthenium catalysts in the synthesis of fine chemicals

Two examples of the application of ruthenium catalysts in fine chemical synthesis are given in this paper. In the first part, protocols for both asymmetric and non-asymmetric epoxidation reactions of olefins employing hydrogen peroxide as a “green” re-oxidant are described. Ruthenium pyridine-2,6-dicarboxylate complexes containing tridentate N-donor ligands are used as homogeneous catalysts. In the second part, a method for the stereoretentive hydrogenation of α-amino acids with water as a solvent is presented. The use of heterogeneous ruthenium catalysts, modified with rhenium, permits the efficient synthesis of the respective amino alcohols with high enantiomeric excess.