NEWS: A Chirasil-Dex column had been on board on the Rosetta mission and landed safely on the comet Tschuri in 11/2014 (https://www.uni-tuebingen.de/aktuelles/newsletter-uni-tuebingen-aktuell/2015/1/forschung/7.html).
Stereochemistry, Enantiomeric Analysis & Synthesis of Chiral Stationary Phases
On the one hand, our research group is concerned with the separation of stereoisomers by chromatography and by electromigration techniques. Different methods, involving gas chromatography, supercritical fluid chromatography, micro liquid chromatography and capillary electrochromatography are employed. A unified approach toward an enantioselective separation system was developed.
Mechanistic aspects of enantiorecognition are investigated thoroughly. Target molecules are chiral drugs, pheromones, flavours, fragrances, inhalation anesthetics and research chemicals. Efforts are directed also to small chiral molecules such as alkyloxiranes, aziridines and fluorochloro(bromo,iodo)methane. In the field of chiral environmental organochlorines, enantiomeric ratios in biogenic matrices are determined. Kinetic data of interconverting enantiomers (enantiomerization) are determined by dynamic chromatography and by stopped-flow multidimensional chromatography.
The precise and correct determination of enantiomeric ratios is the prerequisite for the screening of enantioselective reactions (chirality pool synthesis, catalysis, kinetic resolution, enzymatic transformations) being investigated in parallel.
On the other hand, enantioselective chromatography is improved by the synthesis of new chiral stationary phases. Chiral selectors derived from metal complexes (complexation chromatography) and modified cyclodextrins (inclusion chromatography) were established more than two decades ago.
Chiral selectors bonded to polysiloxanes lead to Chirasil-type stationary phases. Recently new selectors based on chiral resorcinarene derivatives were obtained. Column preparation technologies, e.g. monolithic and packed columns for electrochromatography, represent another topic of the research group. In various co-operations, enantioselective antibodies, enantioselective sensor devices and combinatorial selectors are investigated.