Non-biaryl atropisomers and their stereochemistry have attracted much attentions in the past years. However, application of the non-biaryl atropisomers as chiral solvating agents is yet to be explored. In this work, four aromatic amide-derived atropisomeric phosphine ligands (hosts) were used as chiral solvating agents to recognize various mandelic acid derivatives (guests) in H nuclear magnetic resonance (NMR) spectroscopy. It is found that chiral center configurations of the four hosts have different effects on the enantiorecognition to the used guests. In addition, the host and guest interaction was further investigated by determination of the host-guest complex stoichiometry using the Job's method and density functional theory calculation, respectively. Moreover, chiral analysis accuracy of these hosts was evaluated through relationship between enantiomeric excess values of 4-chloromandelic acid provided by NMR and gravimetry, respectively.
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http://dx.doi.org/10.1002/mrc.5185 | DOI Listing |
J Phys Chem B
January 2025
Institute of Nanotechnology, Karlsruhe Institute of Technology (KIT), Kaiserstraße 12, 76131 Karlsruhe, Germany.
Implicit solvation models permit the approximate description of solute-solvent interactions, where water is the most often considered solvent due to its relevance in biological systems. The use of other solvents is less common but is relevant for applications such as in nuclear magnetic resonance (NMR) or chromatography. As an example, chloroform is commonly used in anisotropic NMR to measure residual dipolar couplings (RDCs) of chiral analytes weakly aligned by an alignment medium.
View Article and Find Full Text PDFACS Omega
January 2025
School of Bio-Chemical Engineering and Technology, Sirindhorn International Institute of Technology, Thammasat University, 99 Phahonyothin Road, Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand.
The integration of molecular docking and AM1 calculations has elucidated the complexation behavior of butylone enantiomers with methylated β-cyclodextrin derivatives. Our study reveals that butylone can adopt two distinct conformations within the β-cyclodextrin cavity, with one conformation being preferentially stabilized due to its favorable binding energy. This conformation preference is influenced by the methylation at the O2, O3, and O6 positions of β-cyclodextrin, which significantly affects complex stability and solvation properties.
View Article and Find Full Text PDFChirality
February 2025
Department of Chemistry, Bogazici University, Istanbul, Turkey.
2-Thiohydantoin derivatives, including different substitutions at N-1 and C-5 (5-methyl-, 5-isopropyl-, 1-acetyl-5-methyl-, and 1-acetyl-5-isopropyl-) (1-4, respectively), were synthesized by the known literature methods. In these synthetic pathways, it was reported that enantiomerically pure 2-thiohydantions were obtained in the absence of any solvent via the reaction of L-amino acids with thiourea (1&2) and via the reaction of L-amino acids with NHSCN and acetic anhydride (3&4). However, in this study, in contrary to the previous literature studies, racemic mixtures of 2-thiohydantoins were obtained although the same synthetic methods were used.
View Article and Find Full Text PDFAnal Chem
January 2025
School of Petrochemical Engineering, Liaoning Petrochemical University, Fushun 113001, China.
Chiral discrimination is an indispensable tool that has pivotal importance in the assignment of absolute configuration and determination of enantiomeric excess in chiral compounds. A series of enantiomerically pure -1,2-diaminocyclohexane (-DACH)-derived benzamides were first synthesized by simple chemical steps, and 14 variated derivatives have been assessed as NMR chiral solvating agents (CSAs) for discrimination of the signals of mandelic acid (MA) in H NMR analysis. The highly efficient chiral recognition of CSA on different substrates, including MAs, carboxylic acids, amino acid derivatives, and phosphoric acids (32 examples), was expanded via H, F, and P NMR spectroscopy.
View Article and Find Full Text PDFActa Crystallogr E Crystallogr Commun
January 2025
Osaka Research Institute of Industrial Science and Technology, 1-6-50 Morinomiya, Joto-ku, Osaka 536-8553, Japan.
The asymmetric unit of the title compound is composed of one host mol-ecule, -4-(1 ,5 -3-aza-1,5(3,9)-dicarbazola-cyclo-octa-phane-3-yl)benzo-nitrile and one di-chloro-methane solvate mol-ecule, CHN·CHCl. The host mol-ecule possesses a planar chirality but crystallizes as a racemate in the space group 2/. It adopts an -configuration, in which two carbazole rings are partially overlapped with a parallel orientation.
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