Chemistry and Materials Science

Abstract: The isoxazole-5-one ring system is a central structure in many synthetic bioactive molecules, showing a wide range of biological activities, including antibacterial, antitumor, anticorrosion, antifungal, antituberculosis, and antioxidant. They are also applied as agrochemical having potential fungicide effects. Given various applications, these pharmaceutically and biologically significant heterocyclic compounds have attracted great attention of the chemistry synthetic researchers. This study aimed to investigate application of glycerol as a reaction medium for the three-component synthesis of arylidenisoxazol-5(4H)-one derivatives. The results of the optimized investigations revealed that 3.0 mL glycerol is the best reaction medium. Evaluation effect of reaction temperature showed that the best temperature for this strategy is 60 °C. In the present environmental friendliness study, the desired heterocyclic compounds were quickly synthesized via a one-pot three-component reaction of two keto-esters with hydroxylamine hydrochloride and a number of aryl/heteroaryl aldehydes. This synthetic approach has significant merits, such as cost-effectiveness of reaction medium, rapid green synthesis, operational simplicity, easy workup, avoid chromatographic purification, sustainability, acceptable yields, relatively inexpensive as well as commercially available starting materials.

Abstract: Despite being discovered over a century ago, lathyrane diterpenoids have only recently attracted significant attention from the organic chemistry community due to their distinctive carbon framework, characterized by a 5/11/3 tricyclic system. The conformational rigidity of these scaffolds promotes close spatial proximity between functional groups, making transannular reactions a powerful tool for the construction of new complex polycyclic architectures. In parallel, compounds from the genus Euphorbia have emerged as privileged scaffolds in medicinal chemistry, exhibiting a wide range of biological activities, including cytotoxic, antiviral, and neuroprotective effects. This review summarizes recent advances in the field, with particular emphasis on synthetic strategies, structural diversity, and medicinal chemistry aspects of this intriguing class of secondary metabolites.

Abstract: This review intends to provide an insight into the wide range of possibilities for vegetable oils to be used as solvents to extract natural ingredients for various applications with special emphasis on antioxidants. The potential of using oils as food-grade solvents for extraction of carotenoids, crocins, curcuminoids, cannabinoids, capsaicinoids, different volatile organic compounds and other lipid-soluble phytochemicals from plant sources and by-products is summarized. Most studies focus on optimizing extraction parameters and evaluating the physical and chemical characteristics of the obtained oily plant extract. On the one hand, these infused or enriched oils can be considered as plant extracts, but, on the other hand, one should not ignore the fact that lipid oxidation is a problem that needs to be addressed. The characterization and analysis of the obtained oily extracts is closely related to their specific application in the food or cosmetic industry. Despite all the advantages, disadvantages related to the stability of the fortified oils are discussed as well.

Abstract: Hydrogen energy is considered to be an ideal energy source for the 21st century due to its clean and renewable nature. However, the large-scale application of hydrogen has been hindered by challenges in storage and transportation. Therefore, the development of safe and cost-effective hydrogen storage materials remains a key focus of current research. Metal-organic frameworks (MOFs) are a novel class of porous materials that can be customized to have different pore sizes. They also feature an ultrahigh surface area, impressive porosity, and excellent thermal and chemical stability. Because of these qualities, MOFs show great promise for hydrogen storage applications. This article provides a comprehensive review of the advancements in hydrogen storage research within MOFs, and examines the factors governing hydrogen storage performance, with particular attention to factors such as metal ion selection, pore architecture, ligand functionalization, and temperature effects. In addition, the article points out the main challenges faced by MOFs in hydrogen storage applications, including high synthesis costs, challenges in large-scale production, and limited structural stability. Finally, it looks ahead to the prospects of MOFs as hydrogen storage materials under mild conditions.

Abstract: Fluorinated isoquinoline-1,3-diones possess important biological activities and application value in many fields such as medicine, pesticides, and organic synthesis.This review summarizes the synthetic methods of fluorinated isoquinoline-1,3-diones in recent years，mainly including traditional synthesis methods，visible light catalysis， electroorganic synthesis. Moreover, the advantages and disadvantages of these methods are discussed. In this review, these synthetic methods are summarized, in order to provide a reference for the design and research of these compounds. Future perspectives on method development are also briefly considered.

Abstract: Herein, Diacetylcurcumin (DAC), a derivative of curcumin, was synthesised, and two new polymorphs (monoclinic and triclinic) are reported in addition to the previously known polymorph (P2₁). Solid-state NMR (CP-MAS) and X-ray studies allowed the unambiguous authentication of the elusive polymorph 2 (canoe-shaped, P2₁/n) and the concomitant polymorph 3 (elliptical-shaped, P-1). We demonstrate that morphological crystal analysis under a microscope, in conjunction with ATR-IR, is a rapid and inexpensive technique for exploring the polymorphic landscape of curcuminoids. This discovery highlights the ongoing progress in curcumin derivative research and should inspire fellow chemists and materials scientists to further explore it.

Abstract: Hysteresis is normally unavoidable in hydrogels under complex external loading conditions due to the intermolecular friction, which usually leads to fatigue. Here, we develop a sarcomere-inspired double-network hydrogel made from polyacrylamide, alginate and phytic acid, whose hysteresis can be precisely modulated by preloading. Particularly, due to the synergy of micellization, fibrillation and micro-lubrication, the as-prepared hydrogel displays an ultra-low hysteresis (≤ 0.02 %) after it experiences a pre-tensile process at a specific amplitude and strain rate, or even possesses negative hysteresis in the case of low tensile amplitudes or high strain rates. Interestingly, smart responses of the developed hydrogel to cyclic tensile loadingare similar to the mechanical behaviors of sarcomeres in vivo. Likewise, the derived hydrogel with ultra-low hysteresis performs reliably even at temperatures as low as -20 ℃. The ultra-low hysteresis presented by the biomimetic hydrogel with ultra-low hysteresis makes it suitable for many engineering fields like electrical sensing with superior reliability (the corresponding electrical signal (ΔR/R0) is stable even after 1000 stretching-unstretching cycles). Moreover, the design strategy of hydrogels with programmable hysteresis provides an innovative methodology for the future development of smart high-performance hydrogels.

Abstract: The title compound 3-(diphenylamino)-4-ethoxycyclobut-3-ene-1,2-dione (6), was prepared by reaction of diphenylamine (2) with diethyl squarate (DES; 5) as part of our ongoing studies on monosquarate-amides. Following purification and recrystallisation, the product was isolated as a green crystalline solid. Its structure was established by spectroscopic methods including: FTIR, ¹H NMR, ¹³C NMR and HRMS and was unambiguously confirmed by single crystal X-ray diffraction. This work provides access to a previously unreported diphenylamino substituted squaric acid derivative.

Abstract: Chirality has emerged as a critical determinant in the design, efficacy, and environmental behavior of modern insecticides. While a significant proportion of agrochemicals are inherently chiral, most are still commercialized as racemic mixtures, despite well-documented differences in biological activity, toxicity, and degradation pathways between enantiomers. In this review, we provide a comprehensive and critical analysis of advances in the stereoselective synthesis and resolution of chiral insecticides, with particular emphasis on neonicotinoids, pyrethroids, and oxadiazines, including indoxacarb. A systematic survey of the literature (1985–2025), including peer-reviewed articles and patents, reveals that multiple strategies have been developed to access enantiomerically enriched compounds, including asymmetric organocatalysis, transition-metal catalysis, chiral-pool approaches, biocatalytic transformations, and chromatographic resolution techniques. Among these, recent developments in photoredox catalysis, recyclable metal complexes, and enzyme-mediated processes have significantly improved enantioselectivity and scalability, bridging the gap between academic methodologies and industrial applications. Despite these advances, challenges remain in achieving cost-effective, sustainable, and universally applicable asymmetric processes. Importantly, the relationship between stereochemistry and biological performance underscores the need for integrating synthetic chemistry with toxicological and environmental studies. Future directions point toward the incorporation of green chemistry principles, continuous-flow processes, and computational tools, including machine learning and molecular modeling, to accelerate the rational design of enantiopure agrochemicals. This review highlights both the progress achieved and the critical gaps that must be addressed to realize the potential of stereoselective insecticide development fully.

Abstract:

Fluoroalkyl-substituted organoboron compounds are valuable building blocks for organic synthesis and for the development of functional molecules in medicinal chemistry, agrochemicals, and materials science. Building on our previous work on difluoromethyl-substituted borates, we report the synthesis and structural characterization of trifluoromethylated borates, 4,4,5,5-tetramethyl-2-aryl-2-(trifluoromethyl)-1,3,2-dioxaborolan-2-uide salts ([pinB(Aryl)CF₃]^–). Treatment of pinB–Aryl boronates (pinB = 4,4,5,5-tetramethyl-1,3,2-dioxaborolane) with trimethyl(trifluoromethyl)silane (Ruppert–Prakash reagent) in the presence of potassium tert-butoxide and 18-crown-6 (18-cr-6) afforded the corresponding trifluoromethylated borates as isolable crystalline compounds. Compared with the related difluoromethylated borates, the CF₃ substituent increases the tendency of [pinB(Aryl)CF₃]^– to exhibit hygroscopic behavior, as supported by a hydrated crystal structure and the formation of a hygroscopic product. The isolable trifluoromethylborates can serve as reservoirs of electrophilic trifluoromethyl radicals upon oxidation.

Abstract: The formation of side products is often unavoidable in organic synthesis; however, analyzing these secondary species provides practical insights into reaction pathways, mechanisms, and competing processes. This understanding is essential for optimizing reaction conditions, increasing product yields, and improving overall safety and efficiency. Additionally, side products can sometimes reveal unexpected molecular structures with valuable properties. In this study, we present the characterization of a compound that formed as a side product in a modified Pictet-Spengler reaction. The molecular structure of 2,2′-(methylenebis(3,4-dimethoxy-6,1-phenylene))diacetic acid was elucidated using a combination of NMR, FTIR, UV–Vis, and HRMS spectroscopic techniques.

Abstract: The synthesis of hydroxamic acids from sterically hindered substrates, such as abietane-type resin acids, remains a significant challenge due to the extreme congestion of the tricyclic skeleton. This study reports an efficient one-pot protocol for the direct conversion of abietic and dehydroabietic acids into their corresponding hydroxamic derivatives, achieving 65% and 74% isolated yields, respectively. Systematic screening of activating agents identified diethyl chlorophosphate (DCP) as the superior reagent for the hydroxy-amidation. A critical finding of this work is that the optimization of the isolation process specifically minimizing the water amount during aqueous work-up was essential to recover these polar products and prevent significant yield loss. The reaction proceeds through diethyl phosphate mixed anhydride intermediate, which was successfully isolated, providing direct experimental evidence of the activation pathway. The reaction mechanism was further elucidated using density functional theory (DFT) calculations at the M062X/6-31G** level, identifying a concerted transition state for the simultaneous addition of hydroxylamine and expulsion of the phosphate group. Furthermore, the study rationalizes the observed chemoselectivity: although the ester is the more stable thermodynamic product, the formation of the N-hydroxy amide is kinetically favored through a substantially lower activation barrier. This combined experimental and theoretical approach establishes a robust and scalable methodology for the functionaliza-tion of abundant similar natural terpenoids.

Abstract: Herein, we investigated the binding properties of four natural compounds extracted from Mediterranean plants—distachyasin, CxB, CxC, and magnoflorine—toward the G-quadruplex (GQ) formed by the KRAS22-RT sequence, a modified KRAS-derived oligonucleotide commonly used as a model of the KRAS oncogene, which adopts a single, well-defined parallel intramolecular GQ structure. Circular dichroism (CD) and nuclear magnetic resonance (NMR) spectroscopies revealed that distachyasin, CxC, and mag-noflorine induced only a slight stabilization of the GQ. In contrast, CxB significantly increased the GQ melting temperature, indicating a markedly stronger stabilizing effect. Notably, the reduced stabilizing effect of its diastereomer CxC highlights how the spatial arrangement of substituents around the core structure can strongly influence the binding properties of ligands towards GQs. Finally, the compounds were evaluated in three breast cancer cell lines and showed antiproliferative effects, particularly in the drug-resistant model.

Abstract: This study focuses on the investigation of the influence of chitosan (CS) and the nature of the support on performance of the hybrid catalysts (Pd-CS/support) in low-temperature hydrogenation of allyl alcohol (2-propen-1-ol). CS-containing palladium catalysts were prepared via sequential deposition of the polysaccharide and palladium onto metal oxide supports (commercial MgO, SiO₂, TiO₂ and synthesized alumina). The synthesized CS-modified palladium catalysts were compared with their polymer-free counterparts. The successful formation of catalysts was confirmed using TGA, XPS, HAADF-STEM, and viscosimetric analysis. The results of low-temperature hydrogenation of 2-propen-1-ol indicate that catalytic activity and selectivity are influenced by both the support nature and chitosan modification. Overall, the introduction of chitosan had a positive effect on both the structural (Pd nanoparticle dispersion and convergence of the electronic properties of the catalysts) and catalytic (activity and selectivity) properties. The obtained results may contribute to controlling reaction pathways in the desired direction in the selective valorization of platform molecules.

Abstract: We report the synthesis and single-crystal X ray structures of three novel (Z)-5 arylidene-3-phenylrhodanine derivatives, differing in the substituents on the ben-zylidene fragment (two methoxy groups (compound I), a dioxine ring (compound II), or a dioxole ring (compound III)). Despite the overall similarity of the molecules, their su-pramolecular architectures were found out to be strikingly different. In both compounds I and II, short S···S chalcogen bonds together with forced C–H···O hydrogen bonds generate dimeric motifs, whereas III lacks S···S interactions and instead features an n→π* contact from the rhodanine carbonyl oxygen to the benzodioxole ring, as well as C-H···S bifurcate hydrogen bond. The results of intermolecular interactions in those structures are checked via Hirshfield surface analysis. The fine modulation of the arylidene substituent can switch the primary intermolecular synthon from chalcogen bonding to n→π* interactions, offering new possibilities for crystal engineering of rhodanine-based materials.

Abstract: Following a description of the woad plant and its distribution in the world, the locations in Europe where commercial woad growing took place during the middle ages until the end of the nineteenth century are described. The four unique steps which were used to convert the leaf of the plant into a dye bath for textile dyeing with indigo are described. The 21st century revival of interest in the process is summarised.

Abstract: Herein, starting from (R)-(+)-α-methylbenzylamine, we report an efficient synthesis and full characterization of a new (R)-3-(1-hydroxyethylidene)-1-(1-phenylethyl)piperidine-2,4-dione, a new tetramic acid analogue. The key steps involved a non-classical Corey-Chaykovsky intramolecular cy-clization reaction to access the corresponding zwitterion, followed by a sequential desul-furization/reduction and condensation procedure. The key intermediate was obtained in 5 steps, and the desired product 7 with an overall 58% yield.

Abstract: Benzofuran and indole are structurally similar compounds, but they show different reactivity patterns. Benzofuran can undergo electrophilic substitution at either the  or  position depending on the electrophile, whereas indole reacts preferentially at the  position. Density functional theory (DFT) calculations of the Wheland intermediates in the Vilsmeier-Haack formylation and nitration reactions are consistent with the experimental results for formylation, but cannot explain the regioselectivity observed in the nitration of of benzofuran. A frontier orbital approach successfully explains the regiochemistry of Vilsmeier-Haack reaction: electron density favors substitution at the  position in benzofuran and at the  position in indole. In contrast, nitration at the  position in both benzofuran and indole can be explained by assuming charge control as the dominant factor governing the reaction.

Abstract: 4-Dimethylamino-2’-hydroxy chalcone (DHC) 1 is an important natural compound that is nearly non-fluorescent in solution but highly fluorescent in its crystalline state. At room temperature, the weak fluorescence from DHC solution is exclusively from its keto tautomer, without notable contribution from its enol tautomer. By using low temperature fluorescence, the study found that the enol emission could be detected upon cooling with liquid N₂ in a protic solvent (e.g. EtOH). This led to observation of the fluorescence vibronic structure of enol tautomer, in addition to its enol emission λ_em ≈ 473 nm that is well separated from its keto tautomer emission (λ_em ≈ 600 nm). By freezing DHC in a solvent matrix, the study revealed the fluorescent characteristics of a single molecule in a rigid environment. Further comparison of DHC in a solvent matrix and crystalline state disclosed that the emission of crystalline DHC was primarily from the keto tautomer, along with some minor contribution from the enol tautomer, despite the tight packing environment in the crystalline state.

Abstract: Syzygium polyanthum (Indonesian bay leaf) is widely consumed as a culinary spice and is traditionally used for health related purposes, yet chemical standardization of region specific materials remains limited, particularly for nonpolar fractions that contain volatile and semivolatile constituents. This study aimed to generate a baseline chemical fingerprint of the n hexane fraction of S. polyanthum leaves collected in Paniki Bawah, Mapanget District, Manado, Indonesia. Dried leaf powder was macerated with 96% ethanol for six days with daily solvent renewal, the filtrate was concentrated under reduced pressure, redissolved in warm distilled water, and fractionated by liquid liquid partitioning to obtain the n hexane fraction. The fraction was analyzed by GC MS, and peak identities were assigned by spectral library matching. Twenty constituents were tentatively identified, dominated by fatty acids and fatty acid methyl esters, with additional aliphatic ketones and terpene related compounds. Major annotations included decanoic acid, dodecanoic acid, tetradecanoic acid, 2 undecanone, 2 tridecanone, nerolidol, and 6,10,14 trimethyl 2 pentadecanone. The clustering of multiple library hits at identical retention times suggests potential coelution; therefore, the reported profile is best interpreted as a qualitative screening fingerprint rather than definitive quantification. Overall, these findings provide a region specific reference for future marker selection, batch to batch comparison, and integration with targeted bioactivity assays to support quality control development for S. polyanthum based products.