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Abstract

The principle of chiral recognition is of central significance in enantioselective catalysis. Therefore, high efficiency in terms of synthesis, separation and analysis of chiral compounds plays an important role. In the first chapter, novel chiral stationary phases for enantioselective separation by gas chromatography will be presented. The chromatographic data provided information on enantiospecific interactions between chiral selectors and selectands. NMR experiments with these selectors in presence of corresponding products of enantioselective catalysis allowed transferring the results from the gas to the liquid phase. This shows that enantioselective gas chromatography can be used as a tool for the screening of selector-selectand interactions. The information obtained was directly applied for the design of a new ligand that can be used in rhodium catalyzed enantioselective hydrogenation. The effect of chiral selectors on dynamic systems was investigated in a double aldol reaction. Therefore, a stereochemical bias was applied onto a dynamic catalyst by addition of an external selector. The induced orientation of the catalyst is reflected the enantiomeric ratio of the chiral product. The excellent separation performance and enantiospecific interactions between the valine based selector with many derivatized amino acids included this structural element covalently bound on a stereodynamic biaryl ligand to give a specifically designed ligandfor asymmetric hydrogenation. This system enables the product of the reaction to transfer chiral information to the coordination complex of catalyst and substrate by interaction with the selectors. In this manner, the chiral information of the product can be transferred on the prochiral substrate. In the second chapter, an accessible chiral derivative of 2,4-disubstitued adamantine diamine was synthesized and separated into its four stereoisomers by reversible derivatization. Combination of unique symmetry and stability make adamantane an interesting structural element in drugs. The isolated and fully characterized stereoisomers of adamantan-2,4-diamine are currently used in medical studies in collaboration as DNA-binder trough influence on the melting temperature of the DNA double helix.