Enantiomeric Recognition in Host-Guest Complexation Using Chiral Bis-pyridino-18-crown-6 Ethers,by Electrospray Ionization Mass Spectrometry (ESI-MS) Enantiomer-Labelled (EL) Guest Method

摘要

Enantiomeric recognition of chiral amino acids by synthetic and natural host compounds is one of the most challenging subjects in modern host-guest chemistry.Host-guest chiral recognition plays an important role in biological process,resolution of enantiomers,and asymmetric catalysis reactions.A number of synthetic model compounds have been designed and synthesized as chiral host molecules that help chemists understand the basis of the mechanism of host-guest complexations and their chiral recognitions.Hence,the successful design,synthesis,and application of chiral macrocyclic ligands with the selective recognition of the guests have attracted much attention for the investigations of catalysis,separations,and enzyme mimics.To determine the chiral recognition of these hosts,various methods of extraction/NMR,extraction/polarimetry,NMR titration,variable temperature NMR,nuclear overhauser effects (NOE),UV-vis titration,HPLC,capillary electrophoresis,transport,and membrane electrode have been used.A high degree of chiral recognition was observed in these studies.