Chromatographic enantioseparation of racemic α-(1-naphthyl)ethylammonium perchlorate by a Merrifield resin-bound enantiomerically pure chiral dimethylpyridino-18-crown-6 ligand

Push or Pull for a Better Selectivity? A Study on the Electronic Effects of Substituents of the Pyridine Ring on the Enantiomeric Recognition of Chiral Pyridino-18-Crown-6 Ethers

Seven dimethyl-substituted optically active pyridino-18-crown-6 ethers containing various substituents at position 4 of the pyridine ring were studied with regards to the electron-donating and -withdrawing effects of substituents on enantiomeric recognition. In order to compile this set of compounds, we prepared four novel pyridino-18-crown-6 ethers, including an intermediate of a new synthetic route for a formerly reported crown ether. The discriminating ability of these pyridino-crown ethers with C2-symmetry toward the enantiomers of protonated primary amines was examined by isothermal titration calorimetry.

Role of chirality and macroring in imprinted polymers with enantiodiscriminative power

Enantioselective discrimination of chiral amines is of great importance as their biological properties often differ. Therefore, here we report the development of synthetic receptors for their enantioselective recognition and pH-sensitive drug release. This paper reports the preparation of three pyridine and two benzene derivatives containing an allyloxy group [(S,S)-5, 6-9] as well as their evaluation as functional monomer anchors for chiral imprinting of amines. The enantiomeric enriching ability and controlled release of the imprinted polymers (IPs) were evaluated using racemic mixture of 1-(1-naphthyl)ethylamine hydrogen perchlorate (1). The effect of the enantiomeric purity of the template on the enantioseparation performance was investigated. Racemic template in combination with enantiomerically pure macrocyclic anchors and vice versa yields IPs with excellent enantiomeric recognition. In vitro drug delivery, enantiomeric enrichment and pH-sensitive release were investigated through kinetic models.

Chiral separation by chromatographic and electromigration techniques. A review

This review gives a survey of different chiral separation principles and their use in high-performance liquid chromatography (HPLC), gas chromatography (GC), supercritical fluid chromatography (SFC), thin-layer chromatography (TLC), capillary electrophoresis (CE) and capillary electrochromatography (CEC) highlighting new developments and innovative techniques. The mechanisms of the different separation principles are briefly discussed and some selected applications are shown.