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Comprehensive Summary: The 21st century has witnessed a continuous evolution in the development of boron‐stereogenic chemistry. Since the 1990s, various innovations for the synthesis of tetracoordinate boron‐stereogenic compounds, which exhibited great potential applications, have been demonstrated by synthetic chemists. This paper reviews the significant progress and recent advances towards the assembly of enantioenriched boron‐stereogenic compounds, and hopes to shed light on new perspectives and inspire further research in this emerging field. [ABSTRACT FROM AUTHOR]

Five new furofuran lignans and their derivatives, (−)-glaberide I 4- O - β -D-glucopyranoside (1a), (+)-glaberide I 4- O - β -D-glucopyranoside (1b), (+)-glaberide I 7'-ethoxy-4- O - β -D-glucopyranoside (2a), (−)-glaberide I 7'-ethoxy-4- O - β -D-glucopyranoside (2b), and (−)-isoeucommin A (3b), along with fifteen known analogs were isolated from the stems of Dendrobium 'Sonia'. These compounds were classified into ten pairs of enantiomers or diastereoisomers via chiral resolution, and their structures were determined based on extensive spectroscopic data. Their absolute configurations were determined by hydrolysis, comparison of experimental and calculated electronic circular dichroism (ECD) data, and single-crystal X-ray diffraction analysis. The isolates were evaluated for their ability to inhibit nitric oxide (NO) production in RAW264.7 cells. Among them, syringaresinol (5) exhibited prominent inhibition activity, with an IC 50 value of 28.4 ± 3.0 μmol·L−1, and there was a slight difference between 5a , 5b and the racemic mixture 5. [ABSTRACT FROM AUTHOR]

Stereoselective inhibition aided by "tailor‐made" polymeric additives is an efficient approach to obtain enantiopure compounds through conglomerate crystallization. The chemical and configurational match between the side groups of polymers and the molecules of undesired enantiomer is considered to be a necessary condition for successful stereoseparation. Whereas in this contribution, we present an effective resolution of chiral pharmaceuticals by using cellulose acetates as the additives, which stereoselectively reside on the specific crystal faces of one enantiomer and inhibit its crystal nucleation and growth through helical pattern and supramolecular interaction complementarity. An investigation of nimodipine serves as a case study to highlight the novelty of this strategy wherein R‐crystals exhibiting an impressive enantiomeric excess value of 97 % can be attained by employing a mere 0.01 wt % cellulose acetate. Guaifenesin and phenyl lactic acid are also well‐resolved by utilizing this methodology. Our work not only brings about a brand‐new design strategy for "tailor‐made" additives, but will also promote the further exploration of the endless potential for utilizing natural biomolecules in chiral recognition and resolution. [ABSTRACT FROM AUTHOR]

Chirality permeates every aspect of life's beauty. To foster a proper understanding of chirality among the public, this paper employs the differences between L- and D-tartaric acid enantiomers to design experiments for popularization of science: (1) Construction of molecular models of tartaric acid enantiomers; (2) Cultivation and observation of tartaric acid crystals; (3) Observation of the optical activity of tartaric acid solutions; (4) Recognition of chirality in tartaric acid molecules. These experiments range from basic to advanced, featuring simple operation, obvious phenomena, interactive communication, and have received positive feedback in the early stages of implementation. [ABSTRACT FROM AUTHOR]

An asymmetric synthesis is a favorable approach for obtaining enantiomerically pure substances, but racemic resolution remains an efficient strategy. This study aims to elucidate the chiral resolution of aromatic amino acids and their elution order using glycopeptides as chiral selectors through molecular docking analysis. Chiral separation experiments were conducted using Vancomycin as a chiral additive in the mobile phase (CMPA) at various concentrations, coupled with an achiral amino column as the stationary phase. The Autodock Vina 1.1.2 software was employed to perform molecular docking simulations between each enantiomer (ligand) and Vancomycin (receptor) to evaluate binding affinities, demonstrate enantiomeric resolution feasibility, and elucidate chiral recognition mechanisms. Utilizing Vancomycin as CMPA at a concentration of 1.5 mM enabled the separation of tryptophan enantiomers with a resolution of 3.98 and tyrosine enantiomers with a resolution of 2.97. However, a poor chiral resolution was observed for phenylalanine and phenylglycine. Molecular docking analysis was employed to elucidate the lack of separation and elution order for tryptophan and tyrosine enantiomers. By calculating the binding energy, docking results were found to be in good agreement with experimental findings, providing insights into the underlying mechanisms governing chiral recognition in this system and the interaction sites. This comprehensive approach clarifies the complex relationship between chiral discrimination and molecular architecture, offering valuable information for creating and improving chiral separation protocols. [ABSTRACT FROM AUTHOR]

Chiral drugs are closely related to the safety and effectiveness of drug use. Most dihydropyridine drugs have chiral carbon atoms, which are used as racemes and produce stereoselective disposal characteristics after entering the body, and may affect the safety and effectiveness of drugs. Therefore, based on the chiral resolution and pharmacokinetic characteristics of this class of drugs, the selection rules of chiral HPLC and CE methods and in vivo analysis applications of this class of drugs in recent years were reviewed. The stereoselective pharmacokinetics of this class of drugs were listed and compared. It was found that some of these drugs had obvious differences in stereoselective pharmacokinetics, and the pharmacokinetics and toxicity in vivo were also different. [ABSTRACT FROM AUTHOR]

Chirality is a fundamental and ubiquitous property of nature involved in multiple fields of science. In particular, the possible resolution of the enantiomeric forms of a molecule is crucial in the pharmaceutical, food, and agrochemical industries. The search for efficient, broad-spectrum, and yet simple methods for obtaining enantiomerically pure substances is a current challenge. Enantioselective resolution methods rely on an asymmetric environment that allows the two antipodes of a chiral molecule to be distinguished. In addition to enantiomeric separation techniques, such as chromatography and electrophoresis, new promising approaches involving out-of-the-scheme synergistic effects between chiral selectors (CS) and external stimuli are emerging. This Trends article discusses different enantioselective mechanisms triggered by unconventional physicochemical stimuli for the design of avant-garde approaches that could offer novel perspectives in the field of chiral resolution. [ABSTRACT FROM AUTHOR]

Flurbiprofen (FB), a nonsteroidal anti-inflammatory drug, is widely employed in treating ocular inflammation owing to its remarkable anti-inflammatory effects. However, the racemic nature of its commercially available formulation (Ocufen®) limits the full potential of its therapeutic activity, as the (S)-enantiomer is responsible for the desired antiinflammatory effects. Additionally, the limited corneal permeability of FB significantly restricts its bioavailability. In this study, we successfully separated the chiral isomers of FB to obtain the highly active (S)-FB. Subsequently, utilizing ion-pairing technology, we coupled (S)-FB with various counter-ions, such as sodium, diethylamine, trimethamine (TMA), and l-arginine, to enhance its ocular bioavailability. A comprehensive evaluation encompassed balanced solubility, octanol-water partition coefficient, corneal permeability, ocular pharmacokinetics, tissue distribution, and in vivo ocular anti-inflammatory activity of each chiral isomer salt. Among the various formulations, S-FBTMA exhibited superior water solubility (about 1-12 mg/ml), lipid solubility (1 < lg Pow < 3) and corneal permeability. In comparison to Ocufen®, S-FBTMA demonstrated significantly higher in vivo antiinflammatory activity and lower ocular irritability (such as conjunctival congestion and tingling). The findings from this research highlight the potential of chiral separation and ion-pair enhanced permeation techniques in providing pharmaceutical enterprises focused on drug development with a valuable avenue for improving therapeutic outcomes. [ABSTRACT FROM AUTHOR]

The incorporation of pentagon‐heptagon pairs into helical nanographenes lacks a facile synthetic route, and the impact of these pairs on chiroptical properties remains unclear. In this study, a method for the stepwise construction of pentagon‐heptagon pairs in helical nanographenes by the dehydrogenation of [6]helicene units was developed. Three helical nanographenes containing pentagon‐heptagon pairs were synthesized and characterized using this approach. A wide variation in the molecular geometries and photophysical properties of these helical nanographenes was observed, with changes in the helical length of these structures and the introduction of the pentagon‐heptagon pairs. The embedded pentagon‐heptagon pairs reduced the oxidation potential of the synthesized helical nanographenes. The high isomerization energy barriers enabled the chiral resolution of the helicene enantiomers. Chiroptical investigations revealed remarkably enhanced circularly polarized luminescence and luminescence dissymmetry factors with an increasing number of the pentagon‐heptagon pairs. [ABSTRACT FROM AUTHOR]

Described herein is the successful crystallization‐induced dynamic resolution (CIDR) of an α‐lithiated phosphine borane utilizing the easily accessible and inexpensive ligand (R,R)‐TMCDA. Starting from the essential P‐prochiral building block dimethyl phenyl phosphine borane we were able to obtain phosphine boranes in yields up to 80 % and e.r. up to 98 : 2 by crystallization of the lithiated intermediate prior to the trapping reaction. NMR‐based deuterium labeling experiments indicate that the epimerization in solution is based on the intermolecular proton transfer between nonlithiated phosphine borane and the corresponding lithiated intermediate, rendering the presence of the remaining starting compound in an optimized solvent mixture the main factor for successful enantioselective synthesis. Quantum chemical calculations using different model systems based on solid state structures confirm these experimental results. By gaining insights into the epimerization mechanism, essential principles for CIDR of lithiated phosphine boranes are elucidated that may be expanded to other important P‐stereogenic compounds and simple chiral amines. [ABSTRACT FROM AUTHOR]

Comprehensive Summary: Eight rare capnosane‐type cembranoids, sarcocinerenoids A—H (1—8) and two new cage‐type cembranoids sarcocinerenoids I—J (9—10) were isolated from the soft coral Sarcophyton cinereum. The 5/11 bicyclic carbon skeleton is the same in Sarcocinerenoids A—H (1—8), and they collocate distinctive oxygen rings. Sarcocinerenoids I—J (9—10) with a cage‐type structure have been discovered to have an oxygen bridge and an uncommon seven‐membered ring. Extensive spectroscopic investigation, X‐ray diffraction analysis, estimated ECD, and DP4+ probability assessments were used to ascertain the structures of the two types of diterpenoids. Moreover, compounds 1, 4 showed promoting angiogenesis activity in zebrafish assays. [ABSTRACT FROM AUTHOR]

Cellulose phenyl carbamates such as cellulose tris(3,5-dimethylphenyl carbamate) (CDMPC) are known to act as chiral selectors when they are coated or immobilized on silica gels that are packed in the columns for high-performance liquid chromatography (HPLC). Previously, we reported a proof of concept of enantioselective membrane filtration using a nonwoven membrane prepared by electrospinning of the CDMPC synthesized from microcrystalline cellulose Avicel®. In the present work, TECHNOCEL® cellulose fiber samples derived from hardwood are functionalized to synthesize CDMPCs having higher and different degrees of polymerization. The length and width of the cellulose fiber samples are characterized using a MorFi image analyzer. The obtained CDMPCs are electrospun to form nanofibrous membranes and their morphology is studied in relation to the electrospinning process parameters, the degrees of polymerization of the CDMPCs, and their solution concentrations. Liquid-liquid permeation experiments of a racemic compound, (R,S)-1-(1-naphthyl)ethanol, through the CDMPC membranes demonstrate preferable permeation of the (S)-enantiomer. This is supported by theoretical simulations using a molecular docking model that indicates stronger hydrogen bonding and π–π interactions with higher binding energy between CDMPC and the (R)-enantiomer than the (S)-enantiomer. [ABSTRACT FROM AUTHOR]

Computational design advances enzyme evolution and their use in biocatalysis in a faster and more efficient manner. In this study, a synergistic approach integrating tunnel engineering, evolutionary analysis, and force‐field calculations has been employed to enhance the catalytic activity of D‐lactonohydrolase (D‐Lac), which is a pivotal enzyme involved in the resolution of racemic pantolactone during the production of vitamin B5. The best mutant, N96S/A271E/F274Y/F308G (M3), was obtained and its catalytic efficiency (kcat/KM) was nearly 23‐fold higher than that of the wild‐type. The M3 whole‐cell converted 20 % of DL‐pantolactone into D‐pantoic acid (D‐PA, >99 % e.e.) with a conversion rate of 47 % and space‐time yield of 107.1 g L−1 h−1, demonstrating its great potential for industrial‐scale D‐pantothenic acid production. Molecular dynamics (MD) simulations revealed that the reduction in the steric hindrance within the substrate tunnel and conformational reconstruction of the distal loop resulted in a more favourable"catalytic" conformation, making it easier for the substrate and enzyme to enter their pre‐reaction state. This study illustrates the potential of the distal residue on the pivotal loop at the entrance of the D‐Lac substrate tunnel as a novel modification hotspot capable of reshaping energy patterns and consequently influencing the enzymatic activity. [ABSTRACT FROM AUTHOR]

We report a unique category of π‐extended diaza[7]helicenes with double negative curvatures. This is achieved by two‐fold regioselective heptagonal cyclization of the oligoarylene‐carbazole precursors through either intramolecular C−H arylation or Scholl reaction. The fusion of two heptagonal rings in the helical skeleton dramatically increases the intramolecular strain and forces the two terminal carbazole moieties to stack in a compressed fashion. The presence of the deformable negatively curved heptagonal rings endows the resulting diaza[7]helicenes with dynamic chiral skeletons, aggregation‐induced emission feature and relatively low racemization barrier of ca. 25.6 kcal mol−1. Further π‐extension on the carbazole moieties subsequently leads to a more sophisticated C2‐symmetric homochiral triple helicene. Notably, these π‐extended diaza[7]helicenes show structure‐dependent stacking upon crystallization, switching from heterochiral packing to intra‐layer homochiral stacking. Interestingly, the C2‐symmetric triple helicene molecules spontaneously resolve into a homochiral lamellar structure with 31 helix symmetry. Upon ultrasonication in a nonsolvent, the crystals can be readily exfoliated into large‐area ultrathin nanosheets with height of ca. 4.4 nm corresponding to two layers of stacked triple helicene molecules and relatively thicker nanosheets constituted by even‐numbered molecular lamellae. Moreover, regular hexagonal thin platelets with size larger than 30 μm can be readily fabricated by flash aggregation. [ABSTRACT FROM AUTHOR]

Zidebactam (WCK 5107) is a novel β-lactam enhancer (BLE), developed by Wockhardt, exhibiting standalone antimicrobial activities against panel of gram-negative pathogens. Zidebactam is referred as β-lactam 'enhancer', because in combination with a partner β-lactam drug, zidebactam not only inhibits the β-lactamases, but also targets PBP2 and enhances the potency of partner drug. The manuscript details the stereoselective synthesis of Zidebactam, as well as the technique/process for preparing the stable sodium salt of (2S,5R)-6-benzyloxy-7-oxo-1,6-diaza-bicyclo[3.2.1]-octane-2-carboxylic acid and the chirally pure side chain, N-Boc-(R)-(-)-ethyl nipecotate hydrazide via chiral resolution. The convergent synthesis of zidebactam has achieved by coupling between sodium salt of DBO carboxylic acid and Boc-(R)-(-)-ethyl nipecotate hydrazide followed by requisite chemical transformations. Single crystal X-ray analysis established the stereochemistry of zidebactam with empirical formula, C13H21N5O7S.2H2O. Currently, two drug combination products zidebactam with cefepime (WCK 5222) and zidebactam with ertapenem (WCK 6777) awarded qualified infectious disease product (QIDP) status by U.S. Food and Drug Administration (USFDA). WCK 5222 has completed phase I clinical trial studies in the USA and is currently undergoing global phase III clinical studies, WCK 6777 is progressing through phase I clinical studies. [ABSTRACT FROM AUTHOR]

Chirality is a fundamental characteristic of nature. Expanded porphyrinoids and their analogues offer an attractive platform for delving into the intricacies of chirality. Expanded porphyrinoids comprise pyrrolic macrocycles and related heterocyclic systems. As a class, expanded porphyrinoids are widely recognized for their flexible structural features, nontrivial coordination capabilities, and intriguing optical and electronic properties. With limited exceptions, their inherent conformational flexibility coupled with a low racemization barrier allows for the facile interchange between enantiomers. As a result, achieving the effective chiral resolution of individual enantiomers and the subsequent exploration of their chiroptical properties represents a significant challenge. This review summarizes strategies used to realize the chiral resolution of expanded porphyrinoids and the understanding of intrinsic chiroptical properties that has emerged from these separation efforts. It is our hope that this review will serve not only to codify our current understanding of chiral expanded porphyrinoids, but also inspire advances in the generalized area of chiral functional materials. [ABSTRACT FROM AUTHOR]

A novel concept of deracemization via periodic fluctuations of solute concentration is demonstrated. Fluctuation of concentration under isothermal conditions was induced by vacuum evaporation followed by re‐addition of solvent. Complete deracemization of a scalemic suspension of N‐(2‐methylbenzylidene)‐phenylglycine amide (NMPA) was achieved. The effects of initial enantiomeric excess, vacuum pressure, and duration of evaporation on the evolution of the solid phase enantiomeric excess and the mechanism of this strategy were studied. Pure enantiomorph NMPA could be achieved by this technique in an efficient and novel procedure. The process has advantages for compounds that have solubility with a weak temperature dependence or compounds that start to decompose at low temperature. [ABSTRACT FROM AUTHOR]

An environmentally friendly bioprocess for the valorisation of the lupanine enantiomeric mixture existing in lupin bean processing wastewater was developed. Pseudomonas putida LPK411, which is capable of enantioselectively biodegrading lupanine enantiomers, was employed for the resolution of the lupanine racemate content of unrefined and pretreated industrial effluents. The optimal culture conditions for racemic lupanine biodegradation by LPK411 were determined as 31 °C, pH 6–7, and 1.5 g L−1 initial lupanine concentration. The results obtained for enantioselective resolution of the effluents by P. putida LPK411, grown in shake-flasks, and a lab-scale bioreactor under batch operation, demonstrated that lupanine resolution was substantially improved in the bioreactor, exhibiting L-(–)-lupanine enantiomeric excess > 93% for all feedstocks used. Moreover, a fed-batch bioprocess was conducted using racemic lupanine resulting in 53% and 49% enhanced D-(+)-lupanine biodegradation and biomass production compared to the corresponding batch experiment respectively, while L-(–)-lupanine concentration increased by 49%. Monitoring the transcriptional kinetics of luh and crc genes employing industrial wastewater and the alkaloid racemate in synthetic media demonstrated that although expression from the lupanine catabolic route was rapidly induced upon supply of lupanine as a single substrate, LPK411 preferably utilised other carbon molecules of the real effluent over lupanine, suppressing the alkaloid's catabolic pathway via the carbon catabolite repression regulatory system. The study exemplified the impact of a preferred compound on the main metabolic route of a bioprocess, demonstrating the importance of molecular interactions in biorefineries developed based on the mixture of substrates contained in renewable bioresources. Future research should aim at optimising and up-scaling the enantioselective biodegradation process proposed. [ABSTRACT FROM AUTHOR]

Chiral resolution is very important and still a big challenge due to different biological activity and same physicochemical property of one pair (R)‐ and (S)‐isomer. There is no doubt that chiral selectors are essentially needed for chiral resolution, which can stereoselectively interact with a pair of isomers. To date, a large amount of optically active helical polymers as chiral selectors have been synthesized via two strategies. First, the target helical polymers are derived from natural polysaccharide such as cellulose and amylose. Second, they can be synthesized by polymerization of chiral monomers. Alternatively, an achiral polymer is prepared first followed by static or dynamic chiral induction. Furthermore, a part of them is harnessed as chiral stationary phases for chromatographic chiral separation and as chiral adsorbents for enantioselective adsorption/crystallization, resulting in good enantioseparation efficiency. In summary, the present review will focus on recent progress of the polymers with optical activity for chiral resolution, especially the literature published in the past 10 years. In addition, development prospects and future challenges of optically active helical polymers will be discussed in detail. [ABSTRACT FROM AUTHOR]

SP 1 sp H NMR (300 MHz, CDCl SB 3 sb ): = 8.69 (d, I J i = 8.0 Hz, 1 H), 7.56-7.55 (m, 2 H), 7.48-7.43 (m, 2 H), 7.35-7.32 (m, 1 H), 7.15-7.09 (m, 4 H), 6.64-6.59 (m, 3 H), 6.50 (d, I J i = 2.4 Hz, 1 H), 5.50 (s, 1 H), 5.39 -5.29 (m, 1 H), 4.69-4.45 (m, 7 H), 4.28 (d, I J i = 13.7 Hz, 1 H), 4.26 (d, I J i = 12.9 Hz, 1 H), 4.15 (d, I J i = 15.0 Hz, 1 H), 3.39 (d, I J i = 13.7 Hz, 1 H), 3.25 (d, I J i = 13.4 Hz, 1 H), 3.20 (d, I J i = 13.5 Hz, 1 H), 3.17 (d, I J i = 12.8 Hz, 1 H), 2.37 (t, I J i = 2.4 Hz, 1 H), 2.36 (t, I J i = 2.4 Hz, 1 H), 1.59 (d, I J i = 6.9 Hz, 3 H), 1.34 (s, 9 H), 1.33 (s, 9 H), 0.85 (s, 9 H), 0.81 (s, 9 H). SP 1 sp H NMR (300 MHz, CDCl SB 3 sb ): = 7.05-7.00 (m, 5 H), 6.86-6.80 (m, 5 H), 4.92-4.66 (m, 4 H), 4.79 (d, I J i = 15.8 Hz, 1 H), 4.53 (d, I J i = 12.6 Hz, 1 H), 4.46 (d, I J i = 12.8 Hz, 1 H), 4.39 (d, I J i = 15.8 Hz, 1 H), 4.28 (d, I J i = 13.6 Hz, 1 H), 4.15 (d, I J i = 13.0 Hz, 1 H), 3.40 (d, I J i = 14.5 Hz, 1 H), 3.30 (d, I J i = 12.7 Hz, 1 H), 3.29 (d, I J i = 13.0 Hz, 1 H), 3.27 (d, I J i = 12.5 Hz, 1 H), 2.65 (t, I J i = 2.4 Hz, 1 H), 2.56 (t, I J i = 2.4 Hz, 1 H), 1.25 (s, 9 H), 1.20 (s, 9 H), 1.01 (s, 9 H), 1.00 (s, 9 H). SP 1 sp H NMR (300 MHz, CDCl SB 3 sb ): = 8.72 (d, I J i = 8.0 Hz, 1 H), 7.61-7.58 (m, 2 H), 7.51-7.46 (m, 2 H), 7.39-7.33 (m, 1 H), 7.18-7.12 (m, 4 H), 6.67-6.62 (m, 3 H), 6.53 (d, I J i = 2.4 Hz, 1 H), 5.54 (s, 1 H), 5.39 -5.29 (m, 1 H), 4.73-4.48 (m, 7 H), 4.31 (d, I J i = 13.6 Hz, 1 H), 4.29 (d, I J i = 12.8 Hz, 1 H), 4.19 (d, I J i = 15.0 Hz, 1 H), 3.43 (d, I J i = 13.9 Hz, 1 H), 3.28 (d, I J i = 13.5 Hz, 1 H), 3.24 (d, I J i = 13.5 Hz, 1 H), 3.20 (d, I J i = 12.8 Hz, 1 H), 2.40 (t, I J i = 2.3 Hz, 1 H), 2.39 (t, I J i = 2.3 Hz, 1 H), 1.65 (d, I J i = 5.8 Hz, 3 H), 1.37 (s, 9 H), 1.36 (s, 9 H), 0.89 (s, 9 H), 0.84 (s, 9 H). [Extracted from the article]

In this work, homochiral reduced imine cage was covalently bonded to the surface of the silica to prepare a novel high‐performance liquid chromatography stationary phase, which was applied for the multiple separation modes such as normal phase, reversed‐phase, ion exchange, and hydrophilic interaction chromatography. The successful preparation of the homochiral reduced imine cage bonded silica stationary phase was confirmed by performing a series of methods including X‐ray photoelectron spectroscopy, thermogravimetric analysis, and infrared spectroscopy. From the extracted results of the chiral resolution in normal phase and reversed‐phase modes, it was demonstrated that seven chiral compounds were successfully separated, among which the resolution of 1‐phenylethanol reached the value of 3.97. Moreover, the multifunctional chromatographic performance of the new molecular cage stationary phase was systematically investigated in the modes of reversed‐phase, ion exchange, and hydrophilic interaction chromatography for the separation and analysis of a total of 59 compounds in eight classes. This work demonstrated that the homochiral reduced imine cage not only achieved multiseparation modes and multiseparation functions performance with high stability, but also expanded the application of the organic molecular cage in the field of liquid chromatography. [ABSTRACT FROM AUTHOR]

Drawing inspiration from a remarkable chiral force found in nature, we show that a static electric field combined with an optical lin ⊥ lin polarization standing wave can exert a chiral optical force on a small chiral molecule that is several orders of magnitude stronger than other chiral optical forces proposed to date, being based on leading electric-dipole interactions rather than relying on weak magnetic-dipole and electric-quadrupole interactions. Our chiral optical force applies to most small chiral molecules, including isotopically chiral molecules, and does not require a specific energy-level structure. Potential applications range from chiral molecular matter-wave interferometry for precision metrology and tests of fundamental physics to the resolution of enantiomers for use in chemistry and biology. [ABSTRACT FROM AUTHOR]

BACKGROUND: Lipase as a hydrolase has important applications in the synthesis of chiral drugs. Based on the special interfacial activity of lipase, bile salt as a biosurfactant can effectively improve the catalytic activity of lipase. RESULTS: In this work, the strong selective recognition of the molecular tweezers and guest molecules helps improve the guest molecule concentration near the lipase catalytic center. However, this strong recognition will also make it difficult for the guest molecules to break away from the molecular tweezers. Therefore, there is an optimal value for this recognition that can effectively improve the chiral resolution effect of lipase. CONCLUSIONS: The two hydroxyl groups on deoxycholic acid were modified to prepare deoxycholic acid‐based molecular tweezers with two 'arms' and one 'crack.' The recognition performance between the molecular tweezers and amino acid methyl ester was determined by UV spectrophotometry. According to the binding constant, Ka, and free energy, −ΔG0, a complex formed between the deoxycholic acid‐based molecular tweezers (host) and amino acid methyl ester (guest) due to chiral recognition. Molecular tweezers were subsequently mixed with porcine pancreatic lipase (PPL) and candida rugosa lipase (CRL), respectively, to catalyze the transesterification of racemic tryptophan methyl ester. © 2023 Society of Chemical Industry. [ABSTRACT FROM AUTHOR]

We report the synthesis of a novel spirocyclic quaternary ammonium salt that possesses axial chirality. Enantiopure material was obtained by fractional crystallization of the corresponding (R,R)‐tartrate salt. Application of this chiral quaternary ammonium salt in phase‐transfer catalytic asymmetric alkylation of glycinate Schiff base was examined. [ABSTRACT FROM AUTHOR]

Non‐centrosymmetric spin‐switchable systems are of interest for their prospective applications as magnetically active non‐linear optical materials and in multiferroic devices. Chiral resolution of simple spin‐crossover chelate complexes into the Δ and Λ forms offers a facile route to homochiral magnetic switches, which could be easily enantiomerically enriched. Here, we report the spontaneous resolution of a new hysteretic spin‐crossover complex, [MnIII(sal2323)]SCN ⋅ EtOH (1), into Δ and Λ forms, without the use of chiral reagents, where sal2323 is a Schiff base resulting from condensation of 1,2‐bis(3‐aminopropylamino)ethane with 2‐hydroxybenzaldehyde. The enantiopurity of the Δ and Λ isomers was confirmed by single crystal X‐ray diffraction and circular dichroism. Quantum chemistry calculations were used to investigate the electronic structure. The opening of a wide 80 K thermal hysteresis window at high temperature highlights the potential for good magneto‐optical function at ambient temperature for materials of this type. [ABSTRACT FROM AUTHOR]

Trans‐β‐lactam isomers have garnered much attention as anti‐cancer microtubule targeting agents. Currently available synthetic methods are available for the preparation of enantiopure β‐lactams and favour isomeric cis/trans β‐lactam mixtures. Indirect chiral resolution offers the opportunity for isolation of exclusively enantiopure trans‐β‐lactams. In this study, liquid chromatography chiral resolution of β‐lactams derivatized as diastereomer mixtures with a panel of N‐protected amino acids is explored, where N‐(Boc)‐L‐proline served as the optimal chiral derivatising reagent. High‐performance liquid chromatography failed to adequately determine diastereomeric excess (de) of resolved diastereomers. Variable temperature, 1H NMR and 2D EXSY spectroscopic analyses of proline‐derivatised diastereomers were successfully employed to characterise equilibrating rotamers of resolved diastereomers and determine their de. Integration of resolved resonances corresponding to H3 and H4 of the β‐lactam ring served as a quantitative qNMR tool for the calculation of de following resolution. [ABSTRACT FROM AUTHOR]

Deracemization extended to racemic‐compound‐forming systems is demonstrated. We present here the first results of an alternative for the resolution of systems that exhibit a stable racemic compound but also a closely related conglomerate‐forming system. If the couples of enantiomers forming the racemic compound and the enantiomers of the stable conglomerate can syncrystallize in mirror‐related partial solid solutions, it is possible to deracemize the racemic mixture of mixed crystals to access to a single handedness. The evidence for this possibility is given in three examples by using temperature‐cycling‐induced deracemization. [ABSTRACT FROM AUTHOR]

Enzyme immobilization has been demonstrated to be a favorable protocol for promoting the industrialization of bioactive molecules, but still with formidable challenge. Addressing this challenge, we create a dynamic defect generation strategy for enzyme immobilization by using the dissociation equilibrium of metal‐organic frameworks (MOFs) mediated by enzymes. Enzymes can act as "macro ligands" to generate competitive coordination against original ligands, along with the release of metal clusters of MOFs to generate defects, hence promoting the gradual transport of enzymes from the surface to inside. Various enzymes can be efficiently immobilized in MOFs to afford composites with good enzymatic activities, protective performances and exceptional reusabilities. Moreover, multienzyme bioreactors capable of efficient cascade reactions can also be generated. This study provides new opportunities to construct highly efficient biocatalysts incorporating different types of enzymes. [ABSTRACT FROM AUTHOR]

A new biocatalyst PCL@UiO‐67(Zr) was successfully synthesized by immobilized lipases on metal–organic frameworks (MOFs) materials. Compare with free lipases, zirconium foundation organic framework material UiO‐67(Zr) modification on immobilized lipases Pseudomonas cepacia lipase (PCL) great boosts their enantioselectivity in the kinetic resolution racemic 4‐chloro‐mandelic acid (4‐ClMA) on the organic solvent. The acquired bio‐composite PCL@UiO‐67(Zr) was fully characterized by powder X‐ray diffraction (PXRD), Fourier transform infrared (FT‐IR) spectroscopy, N2 adsorption–desorption isotherm and aperture distribution map, and scanning electron microscopy (SEM). The catalytic performance of PCL@UiO‐67(Zr), such as temperature, reaction time, and lipase quantity, were deeply explored. The experiment results showed resolution racemic 4‐ClMA optimum conditions that 20 mmol/L of (R, S)‐4‐chloromandelic acid, 120 mmol/L vinyl acetate, 30‐mg immobilized lipases PCL@UiO‐67(Zr), 2 mL of MTBE, 500 rpm, and under the 55°C reaction 18 h. In this optimum conditions, c and eep could reach up to 47.6% and 98.7%, respectively. [ABSTRACT FROM AUTHOR]

Phytochemical investigation of the fruits of Crataegus pinnatifida Bunge led to the isolation of four pairs enantiomeric benzofuran lignans (1a/1b–4a/4b) including four undescribed compounds (1a, 2b, 3b and 4b). Their structures were determined by extensive spectroscopic methods and the absolute configurations were further determined by the comparison of experimental and calculated ECD spectra. All the enantiomeric lignans were evaluated for their inhibitory activities to tyrosinase. Among them, compound 4a showed moderate inhibition activity (IC50 = 0.54 mM). [ABSTRACT FROM AUTHOR]

Both chiral resolving agent and solvent from chiral resolution of the racemate were successfully recovered and recycled by slurry reactive crystallization of its diastereomeric salts. A solvent capable of solubilizing the resolving agent, but not the racemate and its diastereomeric salt products, was selected for chemical processing. The reaction was proceeded through the solid-solid conversion of the racemate into its diastereomeric salt pair, hence the term slurry reactive crystallization. An excessive amount of resolving agent was introduced to ensure reaction completeness, and the unreacted resolving agent was recovered in the filtrate along with the spent mother liquor which was made up by the selected solvent. The filtered solids of diastereomeric salt pair were resolved by recrystallization separately. The same mother liquor was reused as a suspending solvent medium for desalification of the diastereomeric salts by a strong achiral acid/base, in which the cracked resolving agent would be returned to the mother liquor as a solute. By this way, a closed-loop recycle of the resolving agent and suspending solvent medium could be achieved. This concept has been successfully proven by applying it to recover (S)-(-)-1-phenylethylamine as a resolving agent in the chiral resolution of (R,S)-(±)-ibuprofen, with the recovery of 68–70 wt% for up to three cycles. (R,S)-(±)-ibuprofen was resolved to 61–70 wt%R of enriched (R)-(-)-ibuprofen crystals, and up to 77–85 wt%S of enriched (S)-(+)-ibuprofen crystals for up to three cycles. By using this approach, chiral resolution of (R,S)-(±)-ibuprofen could be made to be sustainable with an E-factor of 39.8. [Display omitted] • Resolving agent and solvent were recycled in a chiral resolution process. • The recycling concept was enabled by water-based slurry reactive crystallization. • Phase diagrams were established to aid the resolution. • Resolving agent could be recovered by 68–70 wt% for up to three cycles. [ABSTRACT FROM AUTHOR]

The research progress of chemical resolution in recent years is reviewed, and the research progress of classical salt formation resolution, inclusion resolution and combination resolution are emphatically analyzed, as well as the advantages and disadvantages of each resolution, and finally summarizes and prospects the chemical resolution method.In the future, with the demand of high purity production of high-end chemicals, the optical purity requirements for chiral compounds will be higher and higher.Due to its advantages of simple operation, low cost and easy mass production, chemical resolution is widely used in the separation of enantiomers, and will play an important and irreplaceable role in chiral resolution. [ABSTRACT FROM AUTHOR]

This study aims at developing a high-performance liquid chromatography–mass spectrometry (LC–MS) method to analyze tenofovir disoproxil fumarate (TDF) and its pharmaceutical preparations. Several cyclodextrin mobile-phase additives were applied to reversed-phase and normal-phase chromatography, and the effects of three chiral stationary phases on the TDF separation were investigated in this study. The R-type and S-type of TDF tablets were quantitatively analyzed in the single ion monitoring (SIM) scanning mode with a Unichiral CMD column. This method has been successfully applied to the separation and quantification of TDF and its isomers. The linear ranges of (R)-TDF and (S)-enantiomer were 1–20 and 0.2–16 μg/mL, respectively. The limit of detection for (R)-TDF and (S)-enantiomer was 0.0015 and 0.0012 μg/mL, respectively. (S)-enantiomer was not detected in the formulas from all the seven manufacturers, and the drug content of each took more than 98.5% of the labeled amount, which complies with the regulations. The method shows its advantages on high sensitivity, low detection limit, good practicability, and repeatability. The proposed method may provide a novel platform for separation of TDF enantiomers and quality control of TDF raw materials and preparations. [ABSTRACT FROM AUTHOR]

Abstract Trans‐β‐lactam isomers have garnered much attention as anti‐cancer microtubule targeting agents. Currently available synthetic methods are available for the preparation of enantiopure β‐lactams and favour isomeric cis/trans β‐lactam mixtures. Indirect chiral resolution offers the opportunity for isolation of exclusively enantiopure trans‐β‐lactams. In this study, liquid chromatography chiral resolution of β‐lactams derivatized as diastereomer mixtures with a panel of N‐protected amino acids is explored, where N‐(Boc)‐L‐proline served as the optimal chiral derivatising reagent. High‐performance liquid chromatography failed to adequately determine diastereomeric excess (de) of resolved diastereomers. Variable temperature, 1H NMR and 2D EXSY spectroscopic analyses of proline‐derivatised diastereomers were successfully employed to characterise equilibrating rotamers of resolved diastereomers and determine their de. Integration of resolved resonances corresponding to H3 and H4 of the β‐lactam ring served as a quantitative qNMR tool for the calculation of de following resolution.

Chiral separation membranes have shown great potential for the efficient separation of racemic mixtures into enantiopure components for many applications, such as in the food and pharmaceutical industries; however, scalable fabrication of membranes with both high enantioselectivity and flux remains a challenge. Herein, enantiopure S‐poly(2,4‐dimethyl‐2‐oxazoline) (S‐PdMeOx) macromonomers were synthesized and used to prepare a new type of enantioselective membrane consisting of a chiral S‐PdMeOx network scaffolded by graphene oxide (GO) nanosheets. The S‐PdMeOx‐based membrane showed a near‐quantitative enantiomeric excess (ee) (98.3±1.7 %) of S‐(−)‐limonene over R‐(+)‐limonene and a flux of 0.32 mmol m−2 h−1. This work demonstrates the potential of homochiral poly(2,4‐disubstituted‐2‐oxazoline)s in chiral discrimination and provides a new route to the development of highly efficient enantioselective membranes using synthetic homochiral polymer networks. [ABSTRACT FROM AUTHOR]

To enantioselectively separate a (±)‐ofloxacin (OFX) racemic mixture, we describe the production and successful use of an S‐ofloxacin (S‐OFX) enantio‐selective sorbent with amino functional groups. An amide derivative was first synthesized by reacting the S‐OFX enantiomer with 3‐aminopropyltriethoxysilane (S‐OFX‐Si‐NH2). The generated S‐OFX‐Si‐NH2 derivative was then mixed with tetraethoxysilane (TEOS) and put through a base‐catalyzed sol‐gel condensation polymerization process to insert the S‐OFX enantiomeric species into the cross‐linked material. To facilitate recombination involving S‐OFX, an enantioselective gap is created by alkaline hydrolysis followed by acidification, freeing the S‐OFX from the crosslinked matrix and filling the resulting gaps with cationic ions compatible with the S‐OFX. Our chemical transformations of the monomeric precursor and the ensuing S‐OFX molecularly imprinted material (S‐OFX‐Sil) were confirmed by elemental analysis, nuclear magnetic resonance (NMR), and Fourier transform infrared spectroscopy (FTIR). In addition, scanning electron microscopy images of the sorbent surface were employed to comprehend the morphological adjustments. Both the first loading run (60 % ee of R‐OFX) and the second elution run (83 % ee of S‐OFX) using the manufactured adsorbent particles showed promising separation results. [ABSTRACT FROM AUTHOR]

A non‐aromatic expanded carbaporphyrinoid, incorporating two built‐in 2,7‐pyrenylene moieties was synthesized. The intrinsically labile structure was demonstrated by proton‐triggered conformational changes between the figure‐of‐eight and quasi‐Möbius conformers. Upon treatment with Pd(OAc)2, the reaction produces two bis‐PdII complexes with distinct coordination modes. Metal coordination serves to fix the macrocyclic frameworks with the net result that both bis‐PdII complexes could be resolved by high performance liquid chromatography (HPLC) on a chiral stationary phase. The isolated enantiomers showed persistent chiroptical properties as evidenced by the intense response in the circular dichroism (CD) spectra and the record high absorption dissymmetry factors (gabs of up to 0.038) seen in the near‐infrared spectral region. Moreover, the mutual interconversion of these two PdII complexes was found to be stereospecific and to favor the more stable isomers under weakly acidic conditions. [ABSTRACT FROM AUTHOR]

We report Pd‐catalyzed cyclotrimerization of (+)‐α‐bromoenone, obtained from monoterpene β‐pinene, into an enantiopure cyclotrimer. This C3 symmetric compound has three bicyclo[3.1.1]heptane rings fused to its central benzene with each ring carrying a carbonyl group. The cyclotrimer undergoes diastereoselective threefold alkynylation with the lithium salts of five terminal alkynes (41–63 %, de=4–83 %). The addition enabled a rapid synthesis of a small library of novel chiral cavitands that, in shape, resemble a tripod stand. These molecular tripods include a tris‐bicycloannelated benzene head attached to three alkyne legs twisted in one direction to form a nonpolar cavity with polar groups as feet. Tripods with methylpyridinium and methylisoquinolinium legs, respectively, form inclusion complexes with anti‐inflammatory and chiral drugs (R)/(S)‐ibuprofen and (R)/(S)‐naproxen. The mode of binding shows drug molecules docked in the cavity of the host through ion‐ion, cation‐π, and C−H−π contacts that, in addition of desolvation, give rise to complexes having millimolar to micromolar stability in water. Our findings open the door to creating a myriad of enantiopure tripods with tunable functions that, in the future, might give novel chemosensors, catalysts or sequestering agents. [ABSTRACT FROM AUTHOR]

Preferential enrichment (PE) is a crystallization process, starting from either a racemic of slightly enantio-enriched solution (ca. +5%) that results in a high enantiomeric excess in the liquid phase (>+90%ee) and a slight opposite excess in the deposited crystals (−2 to −5%ee). The mechanism(s) of this symmetry-breaking phenomenon is (are) still a matter of debate since it eludes rationalization by phase diagram formalism. In this publication, we thoroughly reinvestigate the PE phenomenon of arginine fumarate by using a new approach: the process is monitored by introducing isotopically labeled arginine enantiomers into the crystallization medium to better understand the mass exchanges during crystallization. These experiments are supported by chiral HPLC-MS/MS. This study permits re-evaluating the criteria that were thought mandatory to perform PE. In particular, we show that PE occurs by a continuous exchange between the solution and the crystals and does not require the occurrence of a solvent-mediated solid–solid phase transition. [ABSTRACT FROM AUTHOR]

Enantiopure N-heterocyclic carbene half-sandwich metal complexes of the general formula [Cp*M(C^C:)I] (M = Rh, Ir; C^C: = NI-NHC; NI-H = Naphthalimide; NHC = N-heterocyclic carbene) are reported. The rhodium compound was obtained as a single isomer displaying six membered metallacycle and was resolved on chiral column chromatography to the corresponding enantiomers (S)-[Cp*Rh(C^C:)I] (S)-2 and (R)-[Cp*Rh(C^C:)I] (R)-2. The iridium congener, however, furnishes a pair of regioisomers, which were resolved into (S)-[Cp*Ir(C^C:)I] (S)-3 and (R)-[Cp*Ir(C^C:)I] (R)-3 and (S)-[Cp*Ir(C^C:)I] (S)-4 and (R)-[Cp*Ir(C^C:)I] (R)-4. These regioisomers differ from each other, only by the size of the metallacycle; five-membered for 3 and six-membered for 4. The molecular structures of (S)-2 and (S)-4 are reported. Moreover, the chiroptical properties of these compounds are presented and discussed. These compounds display exceptional stable configurations at the metal center in solution with enantiomerization barrier ΔG≠ up to 124 kJ/mol. This is because the nature of the naphthalimide-NHC clamp ligand and the iodide ligand contribute to their configuration’s robustness. In contrast to related complexes reported in the literature, which are often labile in solution.

[Display omitted] • A new chiral surfactant was designed and synthesized. • The chiral surfactant can achieve the purpose of highly efficient resolution of racemic compounds. • The stereoselectivity recognition mechanism of chiral surfactant was revealed at the molecular level. As one of the basic attributes of nature and the universe, chirality is valuable in biology, medicine, and materials science. However, enantiomer resolution remains a long-standing challenge. Herein, a novel surfactant for resolution of racemic compound with high performance has been outlined. Firstly, we synthesized a chiral surfactant and its chiral recognition ability to L-Alanine molecules was confirmed. Subsequently, the solid–liquid equilibrium curves were used to design the resolution route. The synthesized surfactant was further utilized to intensify the crystallization process of the racemic compound, resulting in a remarkable increase of L-Alanine products' ee values from 0% to 99%. Finally, quantum chemical calculations and molecular dynamics simulations were employed to uncover the stereoselectivity recognition mechanism of surfactant to L-Alanine molecules. Overall, we propose a new idea for direct crystallization resolution of racemic Alanine by chiral surfactants that differs from the "rule of reversal", which is highly attractive for chiral resolution. [ABSTRACT FROM AUTHOR]

20-hydroxyprogesterone (20-DHP) is a natural metabolite of progesterone which occurs with two diastereoisomers: 20α-DHP and 20β-DHP. They have drawn attention for their progesterone-like activity since the middle of the 20th century. However, the literature from that era bears witness to a lack of consensus regarding their specific effects. Considered that their stereoisomerism differences, it is essential to investigate their biological activities in vivo separately. In this study, we presented a chemical synthesis technique that yielded highly pure samples of 20α-DHP and 20β-DHP, and performed simultaneous content analysis. Subsequently, we examined and contrasted the progesterone-like properties of 20α-DHP, 20β-DHP, and a 1:1 mixture of 20α-DHP and 20β-DHP. The Morphological observations of the endometrium were conducted via Haematoxylin–eosin staining. Serum hormone levels were measured using enzyme-linked immunosorbent assays. Furthermore, real-time fluorescence quantitative polymerase chain reaction and immunohistochemistry were employed to analyse the relevant mRNA and protein expression, respectively. Our comparison revealed that 20α-DHP and P4 share identical progesterone-like actions, while 20β-DHP exhibits partial similarity. The progesterone activity varied when the two were combined in a 1:1 ratio. [Display omitted] • 20α-DHP and 20β-DHP with excellent purity could be synthesized through an etherification-reduction-deetherification process. • An HPLC procedure has been developed to determining 20α-DHP and 20β-DHP concentration with remarkable reproducibility, linearity, specificity, and accuracy. • In terms of progesterone-like activity, 20α-DHP exhibits the same level as P4, while 20β-DHP shows partial similar. When the two are mixed in a 1:1 ratio, the resulting progesterone activity varies. [ABSTRACT FROM AUTHOR]

Biocatalysis is a valuable industrial approach in active pharmaceutical ingredient (API) manufacturing for asymmetric induction and synthesis of chiral APIs. Herein, we investigated synthesis of a panel of microtubule-destabilising antiproliferative β-lactam enantiomers employing a commercially available immobilised Candida antarctica lipase B enzyme together with methanol and MTBE. The β-lactam ring remained intact during chiral kinetic resolution reactions, plausibly due to a bulky N-1 phenyl substituent on the β-lactam ring substrate. The predominant reaction mediated by CAL-B was methanol catalysed conversion of the β-lactam 3-acetoxy substituent to a 3-hydroxyl group, with preferential methanolysis of the 3 S , 4 S enantiomer. The unreacted substrate underwent progressive enantioenrichment to the 3 R , 4 R enantiomer. Substitution patterns on the B ring C3 meta position of the β-lactam scaffold greatly affected the rate of reaction. Halo substituents (fluoro-, chloro- and bromo-) reduced the rate of conversion compared to unsubstituted analogues, which in turn increased enantiomeric excess (ee). Ee values up to 86 % for the 3 S , 4 S 3-hydroxyl enantiomer were achieved. A double resolution approach for unreacted substrate yielded high ee values (>99 %) for the 3 R , 4 R 3-acetoxy enantiomer. CAL-B mediated methanolysis is a more sustainable method for resolution of racemic antiproliferative β-lactams compared to a previous technique of chiral diastereomeric resolution. Yields of β-lactams obtained using CAL-B are far superior than previously described, which will facilitate progression toward pre-clinical and clinical development. Biocatalysis is a useful tool in the toolbox of the medicinal chemist. [Display omitted] • Kinetic resolution utilised to obtain enantioenriched antiproliferative β-lactams. • A combination of Candida antartica lipase B, methanol and MTBE was required. • 3-Hydroxyl 3 S , 4 S β-lactam was preferentially formed over 3-hydroxyl 3 R , 4 R β-lactam. • Improved yield and efficiency compared to chiral diastereomeric resolution. • Double resolution led to >99 % ee of the 3-acetoxy 3 R , 4 R starting material. [ABSTRACT FROM AUTHOR]

Over the last decades, biocatalysis has achieved growing interest thanks to its potential to enable high efficiency, high yield, and eco‐friendly processes aimed at the production of pharmacologically relevant compounds. Particularly, biocatalysis proved an effective and potent tool in the preparation of chiral molecules, and the recent innovations of biotechnologies and nanotechnologies open up a new era of further developments in this field. Different strategies are now available for the synthesis of chiral drugs and their intermediates. Enzymes are green tools that offer several advantages, associated both to catalysis and environmentally friendly reactants. Specifically, the use of enzymes isolated from biological sources or of whole‐cell represents a valuable approach to obtain pharmaceutical products. The sustainability, the higher efficiency, and cost‐effectiveness of biocatalytic reactions result in improved performance and properties that can be translated from academia to industry. In this review, we focus on biocatalytic approaches for synthesizing chiral drugs or their intermediates. Aiming to unveil the potentialities of biocatalysis systems, we discuss different examples of innovative biocatalytic approaches and their applications in the pharmaceutical industry. [ABSTRACT FROM AUTHOR]

Parasitic diseases, including malaria, leishmaniasis, and trypanosomiasis, affect billions of people and are responsible for almost 500,000 deaths/year. In particular, leishmaniasis, a neglected tropical disease, is considered a global public health problem because current drugs have several drawbacks including to toxicity, high cost, and drug resistance, which result in a lack of effective and readily available therapies. Therefore, the synthesis of new, safe, and effective molecules still requires the attention of the scientific community. Moreover, it is well known that chirality plays a crucial role in the antiparasitic activity of molecules, driving the design of their synthesis. Therefore, in this review we report a recent update on new chiral compounds with promising antileishmanial activity, focusing on synthetic approaches. Where reported, in most cases the enantiopure compound has shown better potency against the protozoa than its enantiomer or corresponding racemic mixture. [ABSTRACT FROM AUTHOR]

Covalent organic framework materials（COFs）are a new type of crystalline porous materials，and their chiral materials have good application prospects in various fields. In this paper，TpBD（NH2 ）2 synthesized by the reaction of 1，3，5-trialdehyde phloroglucinol（Tp）and 3，3´-dinitrobenzidine（BD）was used as the covalent organic skeleton，and reacts with（1S）-（+）-10-camphorsulfonyl chloride（Cam）to prepare（1S）-（+）-10-camphorsulfonyl chloride derivative TpBD-1S-（+）-Cam. The derivative is a newly synthesized chiral covalent organic framework material. TpBD-1S-（+）-Cam was immobilized on silica gel to prepare a chiral column for high performance liquid chromatography to separate racemates. The experimental results show that the prepared COF，TpBD-1S-（+）-Cam，can separate warfarin，chlorpheniramine maleate， atenolol，metoprolol，zopiclone，10-（9-anthryl）-2，2，2-trifluoroethanol，1，2-benzophenone，ketoprofen， mexiletine hydrochloride，timolol 10 kinds of racemates and o，m，p-bromoaniline，o，m，p-iodoaniline are two kinds of positional isomers of benzene series. This material has potential as the stationary phase of high performance liquid chromatography. [ABSTRACT FROM AUTHOR]

Spontaneous resolution leading to conglomerate crystals remains a significant challenge. Here we propose the formation of orthogonal homochiral supramolecular helices in at least two dimensions to allow spontaneous resolution. We suggest the design rationale that the chiral species is made into helical building blocks to allow the helix formation. As a proof‐of‐concept, acetylalanine was made into a helical short azapeptide, its N‐amidothiourea derivative containing a β‐turn structure, to which a halogen atom was further introduced at the phenylthiourea aromatic ring. The resultant folded species undergoes both intermolecular hydrogen and halogen bonding across the turn structure to form orthogonal intermolecular hydrogen‐bonded and halogen‐bonded supramolecular helices in two dimensions, and undergoes chiral resolution upon crystallization. Meanwhile, counterparts containing either an F‐substituent with weak halogen bonding or no halogen atom crystallize as racemic compounds. [ABSTRACT FROM AUTHOR]

The attention to chiral drugs has been raised to an unprecedented level as drug discovery and development strategies grow rapidly. However, separation of enantiomers is still a huge task, which leads to an increasing significance to equip a wider range of expertise in chiral separation science to meet the current and future challenges. In the last few decades, remarkable progress of chiral resolution has been achieved. This review summarizes and classifies chiral resolution methods in analytical scale and preparative scale systematically and comprehensively, including crystallization‐based method, inclusion complexation, chromatographic separation, capillary electrophoresis, kinetic resolution, liquid–liquid extraction, membrane‐based separation, and especially one bold new progress based on chiral‐induced spin selectivity theory. The advances and recent applications will be presented in detail, in which the contents may bring more thinking to wide‐ranging readers in various professional fields, from analytical chemistry, pharmaceutical chemistry, natural medicinal chemistry, to manufacturing of drug production. [ABSTRACT FROM AUTHOR]