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Complexation in situ of 1‐methylpiperidine, racemic 1,2‐dimethylpyrrolidin, and racemic 1,2‐dimethylpiperidine with rhodium(II) tetracarboxylates in chloroform was studied by 1H and 13C nuclear magnetic resonance (NMR) spectroscopy and density functional theory (DFT) methods. As substrates, three dirhodium(II) compounds were applied, tetraacetate, tetrakistrifluoroacetate, and a derivative of optically...
We synthesized the optically active epineoclausenamide by utilizing chiral reagents, such as R‐α‐methylbenzylamine and S‐α‐methylbenzylamine, for the resolution of the intermediate (trans‐3‐phenyl‐oxiranecarboxylic acid 12), followed by amide exchange, cyclization, and reduction, unlike previously reported methods. The Meerwein–Ponndorf–Verley reduction was used to asymmetrically reduce neoclausenamidone...
Chirality is ubiquitous in nature with primary cellular functions that include construction of right‐/left‐handed helix and selective communications among diverse biomolecules. Of particularly intriguing are the chiral peptide‐based materials that can be deliberately designed to change physicochemistry properties via tuning peptide sequences. Critically, understanding their chiral effects are fundamental...
We report on the polymerization/depolymerization of chiral metallo‐supramolecular assembly by CuI/CuII redox change. By combining a monotopic enantiopure ligand with a ditopic ligand of opposite configuration, ML2‐type complexes are generated with chiral self‐recognition or self‐discrimination depending on the oxidation state of copper. In presence of CuI, the formation of heterochiral complexes is...
Microcrystals of l‐Asn‐d‐Trp‐l‐Phe‐NH2 (NdWFamide), a tripeptide derived from Aplysia kurodai that exhibits invertebrate cardiac activity, were evaluated by vibrational circular dichroism (VCD). The chirality of the tryptophan residue at the second position in NdWFamide was associated with the conformation and biological characteristics. The VCD spectrum of NdWFamide was a mirror image of its enantiomer;...
This review addresses the synthesis of enantiopure cryptophane and the study of their chiroptical properties. Cryptophane derivatives represent an important class of macrocyclic compounds that can bind a large range of species in solution under different conditions. The overwhelming majority of these host molecules is chiral, and their chiroptical properties have been thoroughly investigated. The...
Large magnetic optical rotary dispersion (Faraday rotation) has been demonstrated recently in methylammonium lead bromide. Here, we investigate the prospect of extending the active spectral range by altering the halogen. We also investigate the origins of large Faraday rotation in these diamagnetic materials using magnetic circular dichroism (MCD) spectroscopy and the Kramers–Kronig relations. We...
Simultaneous separation of the enantiomer and impurities is a huge challenge for the quality control of the chiral drug. In this work, mixed‐mode chiral ligand exchange stationary phases (CSPs) modified by octyl and sulfhydryl ligands were prepared by vapor deposition and click chemistry methods. Qualitative and quantitative determination of the prepared CSPs were achieved by Fourier transform infrared...
The enantioseparation and resolution mechanism of mandelic acid (MA), 4‐methoxymandelic acid (MMA), and 4‐propoxymandelic acid (PMA) were investigated by reversed‐phase high‐performance liquid chromatography (HPLC) with 2‐hydroxypropyl‐β‐cyclodextrin (HP‐β‐CD) as a chiral mobile‐phase additive and molecular dynamics simulation. The suitable chromatographic conditions for the enantioseparation of MA,...
During the XIXth century, France has been the theater of many discoveries in stereochemistry thanks to prestigious physicists, chemists, and crystallographers. Among them, Louis Pasteur is certainly the father of molecular chirality (the so‐called molecular dissymmetry), and because of the exceptionally favored conditions of his famous discovery on the resolution of tartrates, his findings have often...
Inherently chiral dialkyloxy‐calix[4]arene acetic acids with asymmetric placement of substituents on the lower rim of the macrocycle were first studied as enantiodiscriminating additives to the mobile phase MeCN/H2O/HCOOH (75/25/0.02 by volume) in the high‐performance liquid chromatography (HPLC) separation of d,l‐alanine and d,l‐valine on the achiral stationary phase ZORBAX Original CN. The dependence...
The enantiodiscrimination properties of stereomerically pure inherently chiral calix[4]arene acetic acids, as well as their esters and amides in relation to 1‐phenylethylamine stereoisomers in liquid and gaseous phases were studied by means of proton magnetic resonance spectroscopy (1H NMR) and quartz crystal microbalance (QCM) techniques. Series of QCM sensors with thin films of inherently chiral...
Due to the similar physicochemical properties, the discrimination of chiral isomers faces huge challenges in drug production and biochemical analysis. Herein, the bovine serum albumin‐coated titanium dioxide (bovine serum albumin [BSA]/TiO2) was modified as a novel electrochemical interface for efficient, simple, and enantioselective discrimination of aspartic acid enantiomers (D/L‐Asp) based on the...
Dynamic kinetic resolution (DKR) of unprotected amino acids (AAs), via intermediate formation of Ni(II) complexes, is currently a leading methodology for preparation of natural and tailor‐made AAs in enantiomerically pure form. In this work, we conduct a comparative case study of synthetic performance of four different ligands in DKR of six AAs representing aryl‐, benzyl‐, alkyl‐, and long alkyl‐type...
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