Chiral Recognition of Hydantoin Derivatives Enabled by Tetraaza Macrocyclic Chiral Solvating Agents using ¹H NMR Spectroscopy


Enantiomers of a series of hydantoin derivatives were prepared from d- and l-amino acids with p-tolyl isocyanate and 3,5-bis(trifluoromethyl)phenyl isocyanate as guests for chiral recognition by 1H NMR spectroscopy. Meanwhile, several tetraaza macrocyclic compounds were synthesized as chiral solvating agents from d-phenylalanine and (1S,2S)-(+)-1,2-diaminocyclohexane. An uncommon enantiomeric discrimination has been successfully established for hydantoin derivatives, representatives of five-membered N,N-heterocycles, in the presence of tetraaza macrocyclic chiral solvating agents (TAMCSAs) 1a-1c by means of 1H NMR spectroscopy. Several unprecedented nonequivalent chemical shifts (up to 1.309 ppm) were observed in the split 1H NMR spectra. To evaluate practical applications in the determination of enantiomeric excess (ee), the ee values of samples with different optical purities (up to 95% ee) were accurately calculated by the integration of relevant proton peaks. To better understand the chiral discriminating behavior, Job plots of (±)-G1 with TAMCSA 1a were investigated. Furthermore, in order to further explore any underlying intermolecular hydrogen bonding interactions, theoretical calculations of the enantiomers of (S)-G1 and (R)-G1 with TAMCSA 1a were performed by means of the hybrid density functional theory (B3LYP/6-31G*) of the Gaussian 16 program.




This work was supported by the Scientific Research Fund Performance Award of Beijing Normal University (award number 10200/111203277). Work in the Missouri Lab (P.S.) was supported by the National Institute of General Medical Science of the National Institutes of Health under award number R15GM117508 and R15GM139071.

International Standard Serial Number (ISSN)

1520-6904; 0022-3263

Document Type

Article - Journal

Document Version


File Type





© 2022 American Chemical Society, All rights reserved.

Publication Date

17 Jun 2022