Recent advances of the ionic chiral selectors for chiral resolution by chromatography, spectroscopy and electrochemistry

Abstract

Ionic chiral selectors have been received much attention in the field of asymmetric catalysis, chiral recognition, and preparative separation. It has been shown that the addition of ionic chiral selectors can enhance the recognition efficiency dramatically due to the presence of multiple intermolecular interactions, including hydrogen bond, π-π interaction, van der Waals force, electrostatic ion-pairing interaction, and ionic-hydrogen bond. In the initial research stage of the ionic chiral selectors, most of work center on the application in chromatographic separation (capillary electrophoresis, high-performance liquid chromatography, and gas chromatography). Differently, more and more attention has been paid on the spectroscopy (nuclear magnetic resonance, fluorescence, ultraviolet and visible absorption spectrum, and circular dichroism spectrum) and electrochemistry in recent years. In this tutorial review as regards the ionic chiral selectors, we discuss in detail the structural features, properties, and their application in chromatography, spectroscopy, and electrochemistry.

A Charge-Transfer-Induced Strategy for Enantioselective Discrimination by Potential-Regulated Surface-Enhanced Raman Scattering Spectroscopy

“…Up to now, numerous methodologies have been applied to the discrimination of a pair of enantiomers, including chromatography, spectroscopy, the electrochemistry method, and the colorimetric method [ 10 , 11 ]. Among these methods, the feasibility of enantioselective discrimination based on stereospecific interaction is highly dependent on the affinity of chiral selectors, such as chiral columns, chiral electrodes, and chiral substrates [ 12 , 13 ]. The chiral selectors with the proper structure and molecular polarity are indispensable for sensitive and specific enantioselective discrimination.…”

Development of a capillary electrophoretic method for determination of ketorolac enantiomers in human plasma using cationic β‐cyclodextrin derivative as a chiral selector

“…Nowadays, cationic CD derivatives typically include pyrrolidinium [29,30], amino [26,[31][32][33] groups, or imidazolium [34][35][36] that provide a positive charge. These derivatives of CD can be effective chiral selectors for NSAID separation due to the presence of an aromatic system that can contribute to enantioseparation via π-π interaction between imidazolium cation and ketorolac also containing an aromatic system [37]. The authors [34] have shown that mono-6-deoxy-(alkyl-imidazolium)-β-CD tosylate can be successfully used for the enantioseparation of dan-syl amino acids at BGE pH 8, where amino acids are in anionic form.…”

Wireless electromechanical enantio‐responsive valves

“…More special articles will be found in this issue as well as in those to come.] been developed for the efficient enantiorecognition of chiral probes, [13][14][15] their coupling to delivery systems is still a challenge. An interesting approach is to combine the outstanding enantiorecognition capability of inherently chiral conducting polymers with the highly efficient electromechanical actuation of polypyrrole, [16][17][18][19] triggered by bipolar electrochemistry (BE).…”

“…As such, enantiomeric interactions ultimately control and perturb biological functions; thus, enantiorecognition is of tremendous importance in biological systems. Although different spectroscopic methods have been developed for the efficient enantiorecognition of chiral probes, 13–15 their coupling to delivery systems is still a challenge. An interesting approach is to combine the outstanding enantiorecognition capability of inherently chiral conducting polymers with the highly efficient electromechanical actuation of polypyrrole, 16–19 triggered by bipolar electrochemistry (BE).…”