Search Results (1,115)

Six 9-thienyl-10-aryl-substituted 3,3,6,6-tetramethyl-decahydroacridine-1,8-diones (5a–f) were prepared by two acid-mediated routes that used the same solvent, temperature, and reaction time. In the sequential route, preformed 5,5-dimethyl-3-(arylamino)cyclohex-2-enones were reacted with a heteroaryl aldehyde and dimedone; in the corresponding one-pot route, the arylamine, heteroaryl aldehyde, and two equivalents of dimedone were combined directly. The isolated yields of the product-forming second stage were 71–75%, corresponding to calculated overall two-step yields of 58.2–68.6% after accounting for the isolated enaminone-preparation yields. These overall yields remained higher than those of the one-pot procedure (40–47%), although the sequential protocol required an additional reaction, isolation, catalyst charge, and solvent-intensive operation. Structural assignments were based on the available IR, ¹H NMR, ¹³C NMR, and EI-MS data. Tetrahydroacridinone by-products 6a–c were isolated in 13–15% yields and showed diagnostic spectral changes relative to 5a–f, including loss of the C-9 methine resonance and appearance of a strongly deshielded aromatic proton at 9.17–9.21 ppm. Within the limitations of an operational preparative comparison, the product distribution is consistent with a sequence-control interpretation in which preformation of the β-enaminone favors the 1:1:2 aldehyde/amine/dimedone product, whereas simultaneous component activation permits competing Knoevenagel, xanthene-forming, and aromatization pathways. This study provides a practical synthesis of thienyl-substituted decahydroacridine-1,8-diones and a mechanistically cautious explanation for the reduced selectivity of the one-pot process. Full article

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 agrochemicals with potential fungicidal effects. Given various applications, these pharmaceutically and biologically significant heterocyclic compounds have attracted the attention of chemistry researchers. This study aimed to investigate the 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 of glycerol is the best reaction medium. Evaluation of the effect of reaction temperature showed that the best temperature for this strategy is 60 °C. In the present environmentally friendly 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 the reaction medium, rapid green synthesis, operational simplicity, easy workup, avoiding chromatographic purification, sustainability, acceptable yields, and relatively inexpensive as well as commercially available starting materials. Full article

Cationic lanthanide luminophores remain underexplored compared with their neutral analogues, despite attractive features for solution-processed electroluminescent devices. Here we report the synthesis and characterization of five europium(III) cationic complexes of the type [Eu(L^{N,N})₂(L^{O,O})₂][PF₆], where L^{N,N} = 2,2′-bipyridine, 1,10-phenanthroline, or bathophenanthroline and L^{O,O} = acetylacetonate (acac) or hexafluoroacetylacetonate (hfac). These complexes are obtained in good yield via one-pot reactions from EuCl₃·6H₂O, β-diketonates, and diimine ligands, and are confirmed by FT-IR and RAMAN spectroscopies, elemental analysis, and single-crystal X-ray diffraction to possess well-defined EuO₄N₄ coordination spheres with PF₆ counterions. UV–Vis spectra show intense ligand-centered π–π* bands below ~300 nm and weak visible tails, consistent with efficient antenna sensitization and negligible direct Eu(III) f–f absorption. All complexes exhibit characteristic Eu(III) emission between ~575 and 725 nm, dominated by the ⁵D₀ → ⁷F₂ transition near 610–620 nm for all complexes and ⁵D₀ → ⁷F_3,4 transitions for 4 and 5, with similar line patterns but markedly different intensities. Replacing acac with hfac dramatically enhances performance with the quantum yields increasing from 15–18% to 85–93%, and excited-state lifetimes from 1.01–1.53 ms to 2.50–3.25 ms. These gains are attributed to improved ligand triplet to Eu(III) ⁵D₀ energy matching and reduced multiphonon relaxation, establishing these cationic Eu(III) complexes as promising emitters for solution-processable photonic devices. Full article

The canonical NF-κB pathway is a major regulator of inflammatory responses, and its persistent activation has been linked to chronic inflammatory diseases and cancer development. It is therefore important to develop effective NF-κB inhibitors that can potentially be utilized in further preclinical studies. In this study, we have synthesized various quinazolinone compounds using novel methodologies. We specifically utilized a two-step protocol comparing an established protocol to a modified alternative procedure and then successfully established a novel one-pot multi-component reaction. All quinazolinones were tested based on their capacity to inhibit tumor necrosis factor-induced NF-κB activation using a commercial transgenic HeLa reporter cell-line. Among the eighteen molecules tested, two compounds affected the NF-κB-dependent luciferase activity, the 5o (3-amino-6-hydroxy-2-methylquinazolin-4(3H)-one) and 10 (N-(6-bromo-2-methyl-4-oxoquinazolin-3(4H)-yl)-4-nitrobenzamide). Only the 5o though, bearing OH at R¹ (6 position), attenuated the production of pro-inflammatory interleukin 6 in lipopolysaccharide-stimulated human primary macrophage cultures. Molecular docking analysis provides supportive computational evidence that 5o could interact with the p65/DNA complex and therefore could potentially be developed for further studies that aim to inhibit the canonical NF-κB pathway. Full article

Silica gel polymer material with imprinted phosphate cavities was successfully obtained using one-pot sol–gel reaction. Differences in the textural properties concerning the reduction in specific area and pore size between functionalized and pristine silica gel demonstrated the presence of the phosphate moieties in the cavities. The chemical and structural characterization of the functionalized material before and after copper adsorption was performed by Fourier-transform infrared spectroscopy (FTIR) and solid-state ²⁹Si and ³¹P nuclear magnetic resonance (NMR) spectroscopy. All these measures proposed a phosphate non-covalently bound in the cavities of the silica gel and stabilized by silanol groups on the surface of the matrix. The phosphate–copper complex is removed after the metal desorption process, and the free cavities in the silica matrix can be replenished with phosphoric acid without affecting its adsorption capacity. The entire process of phosphate incorporation, copper adsorption, and metal-ligand desorption was repeated in three cycles, showing a similar metal adsorption capacity. Energy-dispersive X-ray spectroscopy (SEM-EDX) experiments were performed to monitor the presence and proportion of phosphorus and copper at each step of the phosphate loading and copper adsorption processes. These results demonstrate the feasibility of synthesizing a rechargeable polymer material with functional molded cavities with phosphate groups capable of adsorbing copper ions. Finally, this investigation represents the first approach to new materials with a rechargeable ligand system for the adsorption of heavy metals. Full article

Ammonia-selective catalytic reduction (NH₃-SCR) is a well-established and widely applied technology for the abatement of nitrogen oxides. However, traditional NH₃-SCR catalysts still suffer from a limited effective active temperature window, insufficient hydrothermal stability, and relatively high synthesis costs. In this context, Fe-Cu composite Beta zeolites represent an attractive and economically competitive alternative. In the present work, a one-pot, solvent-free method was developed to synthesize Cu- and Fe-containing Beta zeolites using copper-ammonia complexes and Fe salts as metal precursors. The crystalline structure, morphology, and textural properties of the prepared zeolite samples were examined by X-ray diffraction, scanning electron microscopy, temperature-programmed reduction with H₂ and N₂ sorption isotherms. The obtained product displayed high catalytic activity in the NH₃-SCR reaction together with efficient hydrothermal stability, demonstrating potential for practical applications in nitrogen oxide control. Full article

The development of highly efficient and low-cost electrocatalysts for the urea oxidation reaction (UOR) is crucial for advancing urea fuel cell technologies. In this work, MgZnFe-layered double hydroxide (LDH), LDH/BDC-MOF, and LDH/1,2,4-triazole (LDH/TZ) nanocomposites were successfully synthesized via a simple one-pot co-precipitation method. The structural, morphological, textural, and thermal properties of the prepared materials were investigated using XRD, FTIR, SEM, EDX, BET, and TGA analyses. SEM observations revealed that pristine LDH consisted of stacked thin nanosheets with significant layer aggregation, whereas LDH/BDC-MOF exhibited MOF-pillared structures and LDH/TZ formed a highly porous interconnected three-dimensional network that effectively suppressed nanosheet restacking. BET analysis showed a remarkable enlargement in pore size from 6.7 nm for LDH to 34.5 nm for LDH/TZ. The electrocatalytic performance toward UOR was evaluated by cyclic voltammetry, chronoamperometry, and electrochemical impedance spectroscopy in 1.0 M KOH, containing different urea concentrations. Among all investigated electrodes, LDH/TZ exhibited the highest catalytic activity, delivering anodic current densities of 106, 132, 166, 180, and 202 mA cm⁻² at urea concentrations of 0.2, 0.4, 0.6, 0.8, and 1.0 M, respectively. Furthermore, LDH/TZ displayed a lower onset potential of 0.41 V compared with 0.49 V for LDH/BDC-MOF and 0.56 V for pristine LDH. The enhanced activity was further supported by a high double-layer capacitance of 9.7 μF cm⁻², a large electrochemically active surface area of 0.24 cm², and a low charge-transfer resistance of 2.9 Ω. Chronoamperometric measurements demonstrated excellent durability with a stable current density of approximately 73 mA cm⁻² after 3600 s, while cyclic stability reached 94% after 100 cycles. The superior performance of LDH/TZ is attributed to the synergistic effect of the nitrogen-rich triazole ligand, enlarged pore structure, enhanced active-site exposure, and accelerated charge-transfer kinetics, highlighting its strong potential as an efficient electrocatalyst for direct urea fuel cell applications. Full article

A one-pot ball-milling chelation method was used to create Cd(II) and Zn(II) complexes of a 3-hydroxy-2-naphthoyl Schiff base derivative (H₂L), which provided greater efficiency under milder reaction conditions. ¹H NMR, ¹³C NMR, UV–Vis, IR, SEM, XRD, EDX, and elemental studies were used to characterize the isolated solid chelates. The optimized structures were confirmed by DFT theoretical calculations, which also yielded important energetic characteristics such as EHOMO and ELUMO. The three-dimensional crystal structures of HePG-2 (PDB ID: 5EQG), MCF-7 (PDB ID: 6NM0), and HeLa (PDB ID: 5IAE) were carefully analyzed after molecular docking experiments were carried out on the formed complexes utilizing Schrödinger’s LigPrep procedure with default parameters. Finally, the antibacterial, antioxidant, DNA-binding, and cytotoxic properties of the tested solid compounds were assessed. Full article

The cyclobutane ring has attractive properties as a scaffold in medicinal chemistry but is underused, potentially due to the limited methods available for synthesising highly functionalised cyclobutanes. This short note describes the synthesis of the 1,3-cis disubstituted cyclobutane, methyl (S)-3-((1r*,3R*)-3-((1H-indol-3-yl)methyl)cyclobutane-1-carboxamido)-2-(phenylsulfonamido)propanoate using a one-pot thermal stepwise cycloaddition reaction and its characterisation by NMR spectroscopy and HRMS. Full article

A sustainable and scalable one-pot impregnation protocol, avoiding high-temperature calcination/activation, was employed to prepare Pd/Al₂O₃ (0.24 wt%), Pd/TiO₂ (0.18 wt%), Pd/ZrO₂ (0.21 wt%), Pd/SiO₂ (0.37 wt%), Rh/Al₂O₃ (0.18 wt%), and Rh/TiO₂ (0.15 wt%). Support effects on activity, selectivity, and recyclability of these low-metal content heterogeneous catalysts were investigated, using (E)-cinnamaldehyde and levulinic acid as probe molecules. In cinnamaldehyde hydrogenation, Pd catalysts were highly effective for chemoselective C=C reduction to 3-phenylpropanal under mild conditions, with Pd/TiO₂ displaying the highest activity and robust performance over several recycles. However, the Lewis acidity of TiO₂ promoted a solvent-involving side reaction in 2-propanol, with hemiacetal and ether formation, highlighting that apparent selectivity is strongly shaped by support acidity and product residence time. Rh/Al₂O₃ exhibited lower activity than Pd analogues but near-quantitative selectivity to the saturated aldehyde, whereas Rh/TiO₂ again favored hemiacetal formation. In levulinic acid hydrogenation, Pd catalysts were essentially inactive toward ketone hydrogenation even at elevated temperature and H₂ pressure, while Rh catalysts achieved high productivity with exclusive formation of γ-valerolactone, Rh/Al₂O₃ being the most active at comparatively mild pressures. Full article

Developing high-performance non-precious metal catalysts for the methanol oxidation reaction remains a challenge for direct methanol fuel cells. Herein, a nickel-doped Beta (Ni-Beta) zeolite was successfully synthesized via a template-free one-pot hydrothermal route followed by protonation via ammonium exchange. In this work, the protonation process strengthened metal–support interaction to form Ni²⁺/Ni³⁺ redox pairs, introduced abundant acidic sites, and optimized the zeolitic pore structure. Optimized Ni-H-Beta-170 (Si/Ni = 170) achieved a remarkable mass activity of 71.6 A g⁻¹ at 0.66 V vs. Hg/HgO, around 10-fold higher than unprotonated Ni-Beta zeolite. The improved activity originates from reversible Ni²⁺/Ni³⁺ cycles for eliminating toxic CO_ads, enriched acid sites accelerating C–H cleavage of methanol and formation of active NiOOH, and enlarged pore volume facilitating mass transfer. This work offers a low-cost strategy toward advanced non-precious methanol oxidation reaction electrocatalysts. Full article

Reactivity of non-aromatic 2,5-dichloro-2H-pyrroles toward S-nucleophiles was investigated. It was found that these non-aromatic derivatives exhibit both oxidative and electrophilic properties. Their reaction with thiols and xanthates proceeds as redox process to form disulfides and 5-chlorinated pyrroles as a result of 2,5-dichloro-2H-pyrroles reduction. However, the reaction with ammonium thiocyanate afforded the corresponding 5-thiocyanated 1H-pyrroles. Based on these findings, a novel one-pot method for the thiocyanation of 2,3,4-trisubstituted pyrroles was developed. The protocol involves the in situ generation of highly reactive 2,5-dichloro-2H-pyrroles via dearomative chlorination of the corresponding pyrroles using trichloroisocyanuric acid (TCCA). Subsequent addition of ammonium thiocyanate leads to regioselective incorporation of a thiocyanate group at the C5 position and rearomatization of the pyrrole core. A broad scope of pyrrole-5-thiocyanates was obtained in yields up to 82%. Furthermore, these derivatives were efficiently transformed into 5-trifluoromethylthiolated pyrroles using Ruppert’s reagent in up to 94% yield. This reaction sequence provides a cost-effective way to obtain 5-trifluoromethylthiolated pyrroles, avoiding the need for high-cost electrophilic reagents. The synthetic utility of these novel sulfur-containing pyrrole derivatives was also demonstrated. Full article

Scaffolds designed for mechanically demanding soft tissue engineering applications should integrate mechanical support, efficient mass transfer, and good cellular compatibility. This work presents a one-pot method based on “radical-free click chemistry + carbodiimide coupling” to produce a double-network (DN) PEG–alginate cryogel. The PEG network is formed by a Michael addition reaction between thiol-based crosslinker and 8-arm PEG-acrylate. The second network is covalently crosslinked through EDC/NHS-mediated coupling of carboxyl groups in alginate and adipic acid dihydrazide (AAD). The subsequent freezing and gelation of the gel precursor at sub-zero temperatures results in an ice templated cryogel with an interconnected macroporous network. These cryogels demonstrate high elasticity, compressive modulus and rapid swelling equilibrium in aqueous environments, as well as controlled degradation under physiological conditions. Compared to the classical Ca²⁺ ion crosslinking systems, the covalent linking of the alginate in the double-network cryogel shows advantages in mechanical and structural stability. In addition, it is cell-compatible and allows culture of mesenchymal stem cells (MSCs) with homogeneous infiltration. Furthermore, the double-network cryogels supports chondrogenic differentiation of MSCs upon treatment with chondrogenic media or macrophage-conditioned media for a short period of time. These results indicate that crosslinking chemistry and polymer composition can be used to modulate the balance between mechanical performance and degradation behavior, while maintaining cytocompatibility and an interconnected macroporous network, thereby providing a scaffold design strategy for applications that require coordinated mechanical support and mass transfer, such as cartilage-related tissue engineering. Full article

Three kinds of nitrogen-doped carbon quantum dots (N-CQDs) were successfully fabricated through a one-pot hydrothermal reaction at 180 °C for 12 h. L-lactic acid served as the carbon precursor, while three phenylenediamine isomers (o-phenylenediamine, m-phenylenediamine, p-phenylenediamine) were employed as nitrogen dopants, yielding samples denoted as OPD-LA, MPD-LA, and PPD-LA. All as-prepared N-CQDs presented uniformly dispersed spherical nanostructures, with average particle sizes of 8.2 nm (OPD-LA), 9.3 nm (MPD-LA), and 10.5 nm (PPD-LA). Abundant surface functional groups, including hydroxyl, carboxyl, amino, and amide moieties, endowed these N-CQDs with outstanding water solubility and tailorable fluorescence emission. The maximum emission wavelengths were centered at 550 nm, 505 nm, and 450 nm for OPD-LA, MPD-LA, and PPD-LA, respectively, exhibiting excitation-independent emission positions yet excitation-dependent intensity. MPD-LA delivered the highest fluorescence quantum yield of 9.59%, and the incorporation of lactic acid significantly elevated the quantum yield of all samples. The N-CQDs maintain high fluorescence intensity and favorable stability within the pH range of 4–11, possessing outstanding salt resistance and stable storage performance for six months. Their fluorescence was effectively quenched upon exposure to Fe³⁺, with a linear detection range of 10–100 μM and a low limit of detection (LOD) of 1.49 μM. These lactic acid-derived N-CQDs hold great promise as functional fluorescent probes for Fe³⁺ sensing applications. Full article

Beta-alanine, a naturally occurring non-proteinogenic beta-amino acid, is widely used in delaying fatigue, enhancing exercise performance, and alleviating hyperuricemia. It also serves as a three-carbon platform for the synthesis of various high-value compounds, thus showing extremely broad market prospects. However, the practical application of beta-alanine is severely limited by the harsh reaction conditions and abundant by-products in chemical synthesis, as well as the low endogenous content and complex biosynthetic pathway. Recently, advances have been made in the one-pot, one- or two-step production of beta-alanine using genetically engineered recombinant enzymes, and in the microbial synthesis of beta-alanine via whole-cell biocatalysis. These advances are based on a series of attempts, including the enzymatic conversion to beta-alanine using 1,3-diaminopropane (DAP), L-aspartate (L-Asp), fumarate, or 3-aminopropionitrile as substrates, and the whole-cell biosynthesis of beta-alanine by regulating metabolic flux from carbon sources (e.g., glucose, oil, and glycerol) to L-Asp—the precursor for beta-alanine synthesis catalyzed by L-aspartate-α-decarboxylase (ADC). This study provides a rational theoretical basis and valuable practical references for the future industrial application of beta-alanine. Full article