“…The investigation of the chiral recognition of carboxylic acids by artificial receptors was of critical importance in the preparation, separation, and analysis of enantiomerically pure carboxylic acids and disclosing the mechanism of interaction of the carboxylic acids with biological systems. Therefore, a variety of chiral shift reagents, such as chiral amines,19–24 amino alcohols,25 Tröger's Base,26 macrocyclic amines and amides,27–34 crown ethers,35–37 and calixarenes,38–43 have been described in the literature to determine the enantiomeric purity and understand the basis of the mechanism of host–guest complexations. To date, however, there are only a few examples of proline‐derived receptors44, 45 for the enantiomeric recognition of carboxylic acids.…”