Short Reaction Times Research Articles

Sustainable and versatile Aza-Michael additions promoted by acidic ionic liquids

Acidic ionic liquids are a subset of ionic liquids where the cation or anion possess acidic properties with huge applications in various fields. Here we describe environmentally safe and highly efficient conjugate addition of aromatic and aliphatic amines to α, β-unsaturated compounds in the presence of novel acidic ionic liquids. The acidic ionic liquid catalyst was prepared by combining benzyl chloride with 2-(dimethylamino) ethanol and SnCl2 in a simpler manner. The resulting acidic ionic liquid was characterized using SEM, EDS and FTIR spectroscopy. In the presence of ionic liquids, a wide variety of amines undergo facile conjugate addition to α, β-unsaturated compounds affording the corresponding β-amino compounds in good to excellent yields (72–97 %), shorter reaction times (1–4 h) and mild reaction conditions (60 °C). Furthermore, the study demonstrated the sustainability of the process by showcasing that the acidic ionic liquids could be reclaimed and reused for up to five cycles without compromising their catalytic effectiveness.

Synthesis, characterization, and catalytic activity of zinc-isonicotinic acid MOF

The synthesis and characterization of Zn (INA) microcrystalline MOF was conducted, revealing its high catalytic activity in the production of substituted benzyl alcohol (BzOH) to substituted benzaldehyde (BzA). The MOF was found to be cost-effective and efficient, with a short synthesis time and moderate reaction conditions. The MOF's structure was confirmed through XRD, SEM, and TEM imaging, and its purity was confirmed through EDS analysis. The TGA investigation revealed significant thermal stability with minimal weight loss and BET studies shows the substantial surface area and pore volume, suggesting potential for various industrial uses. The MOF's efficiency under mild reaction conditions, low cost, and absence of noble metals makes it a promising candidate for sustainable catalytic applications.

Role of Nanoparticle Size in the Photocatalytic Degradation of Pollutants

Purpose: The aim of the study was to assess the role of nanoparticle size in the photocatalytic degradation of pollutants. Methodology: This study adopted a desk methodology. A desk study research design is commonly known as secondary data collection. This is basically collecting data from existing resources preferably because of its low cost advantage as compared to a field research. Our current study looked into already published studies and reports as the data was easily accessed through online journals and libraries. Findings: The study indicated that smaller nanoparticles exhibit a higher surface area-to-volume ratio, providing more active sites for pollutant interaction and adsorption, which enhances the overall degradation process. Additionally, smaller nanoparticles tend to have higher charge carrier mobility and reduced recombination rates of electron-hole pairs, further improving photocatalytic activity. This increased efficiency is critical in environmental applications, as it allows for the effective breakdown of various contaminants, including dyes, pesticides, and pharmaceuticals, at lower catalyst loadings and shorter reaction times. The optimization of nanoparticle size, therefore, plays a crucial role in developing advanced photocatalytic systems for environmental remediation. Implications to Theory, Practice and Policy: Optical absorption theory, surface area and reaction kinetics theory and charge carrier dynamics theory may be used to anchor future studies on assessing the role of nanoparticle size in the photocatalytic degradation of pollutants. Develop robust methodologies for synthesizing nanoparticles with precise control over size distribution. Establish standardized protocols for evaluating the performance and safety of nanoparticle-based photocatalytic materials. This includes setting benchmarks for degradation efficiency, durability, and potential environmental impacts.

RAPID AND AN EFFICIENT ONE-POT THREE-COMPONENT SYNTHESIS OF ISOXAZOLES PROMOTED BY CAS

A straightforward, practical, and economical process for producing isoxazole derivatives is described. It makes use of ethylacetoacetate, hydroxylamine hydrochloride, and substituted aromatic aldehydes with promoted camphor sulfonic acid as a catalyst in a solvent. No toxic organic solvents are used in the current procedure. Shortest reaction time, high product yields, easy work-up process, and non-chromatographic product purification are only a few of this catalysts encouraging reaction response characteristics. The derivatives of desired compounds were analyzed advanced spectroscopic data by 1H NMR, 13CNMR and mass spectrometry was used to verify the products structures. Products were chosen, and their antibacterial activity was examined.

MPC@But-SO3H a mesoporous heterogeneous organocatalyst in one-pot tandem synthesis of dihydroindeno[1,2-b]pyrrole derivatives

A sustainable, metal-free, and highly efficient protocol for the synthesis of dihydroindeno[1,2-b]pyrrole derivatives via a tandem one-pot three-component reaction in aqueous medium at room temperature using an effective and reusable mesoporous heterogeneous organocatalyst, MPC@But-SO3H has been developed. MPC@But-SO3H was easily synthesized using a melamine-based covalent organic polymer and 1,4-butane sultone. The organocatalyst was well characterized by numerous spectroscopic techniques such as Fourier Transform Infrared (FTIR), Brunauer-Emmett-Teller (BET), X-ray photoelectron spectroscopy (XPS), Powder X-ray diffraction (PXRD), Scanning Electron Microscope (SEM), Energy Dispersive X-ray (EDX), elemental mapping, and Thermal Gravimetric (TG) analyses. The catalyst displayed excellent catalytic potential, high thermochemical stability, and reusability for up to eight catalytic cycles. It offered the title compounds in excellent yields (˃90%) in a short reaction time (9-14 min). The synthesized compounds were characterized through FTIR, 1H, and 13C Nuclear Magnetic Resonance (NMR), and the molecular structure of 2-(benzylamino)-3a,8b-dihydroxy-1-methyl-3-nitro-3a,8b-dihydroindeno[1,2-b]pyrrol-4(1H)-one (4a) was confirmed by the Single Crystal XRD (SC-XRD) analysis. The key features of the present protocol include the use of water as a green solvent, zero involvement of any metal, sustainable reaction conditions, easy catalyst recovery, and a simple work-up procedure. The calculations for green metrics parameters further supported the greenness and sustainability of the protocol.

(Diethylamino)sulfur trifluoride (DAST)-mediated oxidation of benzylic alcohols and amines to carbonyl compounds

We report an efficient protocol for oxidation of primary/secondary benzyl alcohols and benzylamines to produce corresponding aldehydes or ketones. Our unified method involves the use of commercially available (diethylamino)sulfur trifluoride (DAST) as a reagent combined with DMSO as solvent and oxidant. The reaction provided corresponding carbonyl compounds in good to excellent yields with high purity and in short reaction times.

Ag-MOF Nanocatalyst for the Asymmetric Hantzsch Synthesis of Polyhydroquinolines Under Green Conditions

A highly efficient and stable heterogeneous coordination polymer (CP) catalyst was successfully prepared by hydrothermal reaction of silver and 4,6-Diamino-2-pyrimidinethiol, using amine, thiol and pyrimidine functional groups. Besides, silver ions were coordinated to the ligand functional groups in order to give a novel Ag-CPs catalyst. Besides, it was characterized using FT-IR, XRD, TGA, SEM, EDX, X-ray mapping and BET analysis. The prepared Ag-CPs exhibit excellent catalytic activity for multicomponent Hantzsch synthesis of polyhydroquinolines under mild reaction condition in relatively short reaction times. The heterogeneity of the catalyst was confirmed by the hot filtration test and, then, the catalyst was reused for at least four times under the optimized conditions without any significant loss of its activity.

Preparation of functionalized magnetic nanoparticles bearing sulfonic acid as an effective reusable solid acid catalyst for the synthesis of benzothiazoles

In this study, solid acid magnetic nanoparticles Fe3O4@SiO2-S-Bu-SO3H were prepared under appropriate conditions and characterized by various analytical techniques including FT-IR, XRD, FE-SEM, EDX, and VSM. Finally, the catalytic activity of the synthesized Fe3O4@SiO2-S-Bu-SO3H MNPs was investigated for the synthesis of valuable benzothiazole derivatives by the condensation reaction of ortho-aminothiophenol and various aldehydes under ultrasonic conditions. In the presence of the inexpensive, environment-friendly, magnetically recoverable solid acid catalyst, the benzothiazoles were obtained as pure target products in excellent yields (90–98%) and short reaction times (3–11 min). The synthesized Fe3O4@SiO2-S-Bu-SO3H MNPs show great catalytic activity because of the combined effect of Brønsted acidity and high functional group density. This solid acid magnetic nanocatalyst is reusable for several cycles and can be easily segregated from the reaction mixture.

Transition metal-free efficient synthesis of bis(indolyl)propynes (BIPs).

A transition metal-free approach has been devised for the synthesis of a variety of bis(indolyl)propyne (BIP) derivatives. The strategy involves an iodine-catalyzed cascade condensation of α,β-unsaturated acetylenic aldehydes with diversely substituted indoles. The strategy was applicable to gram scale synthesis and a library of 50 molecules, which were afforded in good to excellent yields (up to 96%), was developed. The salient features of the reaction involve the synthesis of indole based privileged scaffolds in a short reaction time under transition metal-free conditions, with a wide substrate scope and excellent yields under ambient conditions.

Microwave‐Assisted Copper‐Catalyzed Synthesis of 1‐Aryl Benzotriazole 3‐Oxides

AbstractIn this work, we present a copper‐catalyzed rapid and efficient method for cross‐coupling of N‐hydroxy benzotriazole with boronic acids under microwave irradiation for the synthesis of 1‐aryl benzotriazole 3‐oxides. This protocol tolerates a wide range of substituted boronic acids to provide the corresponding products in good to excellent yields. The features of this strategy include a broad substrate scope, high functional group tolerance, short reaction time, and good to excellent yields.

Frontal Activity of Recent Suicide Attempters: EEG spectrum Power Performing Raven Task.

Background: Deficits in problem-solving may be related to vulnerability to suicidal behavior. We aimed to identify the electroencephalographic (EEG) power spectrum associated with the performance of the Raven as a reasoning/problem-solving task among individuals with recent suicide attempts. Methods: This study with the case-control method, consisted of 61 participants who were assigned to three groups: Suicide attempt + Major Depressive Disorder (SA + MDD), Major Depressive Disorder (MDD), and Healthy Control (HC). All participants underwent clinical evaluations and problem-solving abilities. Subsequently, EEG signals were recorded while performing the Raven task. Results: The SA + MDD and MDD groups were significantly different from the HC group in terms of anxiety, reasons for life, and hopelessness. Regarding brain oscillations in performing the raven task, increased theta, gamma, and betha power extending over the frontal areas, including anterior prefrontal cortex, dlPFC, pre-SMA, inferior frontal cortex, and medial prefrontal cortex, was significant in SA + MDD compared with other groups. The alpha wave was more prominent in the left frontal, particularly in dlPFC in SA + MDD. Compared to the MDD group, the SA + MDD group had a shorter reaction time, while their response accuracy did not differ significantly. Conclusions: Suicidal patients have more frontal activity in planning and executive function than the two other groups. Nevertheless, it seems that reduced activity in the left frontal region, which plays a crucial role in managing emotional distress, can contribute to suicidal tendencies among vulnerable individuals. Limitation The small sample size and chosen difficult trials for the Raven task were the most limitations of the study.

Ultrasound assisted solvent-free approach for the synthesis of 4-thiazolidinone derivatives

An economical and environment-friendly protocol involving the use of ultrasonic vibrations was developed for the synthesis of a series of diaryl-4-thiazolidinones. The highlights of the developed approach are significant enhancement in the product yield, short reaction time, solvent-free, free of any toxic metal as a catalyst, cheaper synthetic methodological approach as well as non-formation of side-products. The developed approach is useful in terms of immense biological relevance of thiazolidines as well as the greener approach for cyclo-condensation of functionalized imines with thioglycolic acid.

Effect of Phasic Experimental Pain Applied during Motor Preparation or Execution on Motor Performance and Adaptation in a Reaching Task: A Randomized Trial.

Musculoskeletal conditions often involve pain related to specific movements. However, most studies on the impact of experimental pain on motor performance and learning have used tonic pain models. This study aimed to evaluate the effect of experimental phasic pain during the preparation or execution of a reaching task on the acquisition and retention of sensorimotor adaptation. Participants were divided into three groups: no pain, pain during motor preparation, and pain during motor execution. Pain was induced over the scapula with a laser while participants performed a force field adaptation task over two days. To assess the effect of pain on motor performance, two baseline conditions (with or without pain) involving unperturbed pointing movements were also conducted. The results indicated that the timing of the nociceptive stimulus differently affected baseline movement performance. Pain during motor preparation shortened reaction time, while pain during movement execution decreased task performance. However, when these baseline effects were accounted for, no impact of pain on motor adaptation or retention was observed. All groups showed significant improvements in all motor variables for both adaptation and retention. In conclusion, while acute phasic pain during motor preparation or execution can affect the movement itself, it does not interfere with motor acquisition or retention during a motor adaptation task.

One pot multi-component synthesis of novel functionalized pyrazolo furan-2(5H)-one derivatives: in vitro, DFT, molecular docking, and pharmacophore studies, as coronavirus inhibitors.

New and facile one-pot approach for the syntheses of 12 derivatives of 3,5-disubstituted furane-2(5H)-one (4a-l) from easily available starting materials. The suitable synthetic procedures for selective synthesis of diverse furane-2(5H)-one derivatives were achieved via multi-component condensation of 1,3-diphenyl-1H-pyrazole-4-carbaldehyde (1), pyruvic acid and different aromatic amines 3a-l in good to high yields and short reaction time by refluxing in acetic acid as well as obtained by another method (method B) when unsaturated arylidene pyruvic acid 6 was refluxed with different aromatic amines in acetic acid but in smaller yield than method A. Structures of the prepared compounds were elucidated by elemental analysis and spectral data as mass, IR, 1H-NMR and 13C-NMR spectroscopy. The antiviral efficacy of compounds 4a-l against SARS-CoV-2 was evaluated using the MTT assay. It was demonstrated that synthetic compounds 4c-e and 4h-j have a potent and selective inhibitory effect on SARS-CoV-2, a strain obtained from Egyptian patients. We utilized density-functional theory (DFT) analyses to deduce the molecular structures and topologies of the more energetic molecules. Molecular docking studies were performed against the SARS-CoV-2 main protease (PDB ID: 6Y84) and the SARS-CoV-2 Nsp9 RNA binding protein (PDB ID: 6W4B) to study the binding mechanism, non-bonding interactions, and binding affinity. Lastly, a hypothetical pharmacophore model was constructed by applying the Molecular Operating Environment (MOE) tool and eleven pharmaceuticals with proven antiviral activity.

Synthesis and evaluation of palladium-functionalized biochar-supported magnetic nanoparticles for efficient nitro reduction

This study investigated the catalytic activity of the magnetic Fe3O4@Bio-R-Pd (Bio = biochar, R = epichlorohydrin and guanidine) for the reduction of nitro compounds. The structural and magnetic properties of the synthesized nanocatalyst were characterized using a suite of techniques including inductively coupled plasma spectrometry (ICP), vibrating sample magnetometer (VSM), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), Fourier Transform infrared (FT-IR) spectroscopy, and X-ray diffraction (XRD). The recyclability of the synthesized nanocatalyst was confirmed by its complete reversibility upon testing with a vibrating magnetometer, further supporting its paramagnetic nature. Analysis of the SEM images revealed the presence of spherical magnetite particles within the composite. Using these optimized conditions, various aromatic nitro compounds were successfully reduced in the presence of the Fe3O4@Bio-R-Pd catalyst. The results demonstrate the advantageous properties of the synthesized nanocatalyst, including high product yield, stability and resistance at high temperatures, easy separation from the reaction medium, high efficiency with short reaction times, and economic viability. Notably, the synthesized sample exhibited nearly the same initial efficiency after 5 reuses, indicating almost complete recovery and minimal change in its catalytic activity.

The Oxidation of Electron-Rich Arenes Using a H2O2-Proline System.

This study introduces a novel proline-catalyzed oxidation system employing hydrogen peroxide to synthesize quinones from a diverse range of substrates, including hydroquinones, phenols, resorcinols, aldehydes, and polycyclic aromatics. This approach is well-aligned with green chemistry principles, offering a more environmentally benign approach than earlier studies. Notably, this approach uses cost-effective reagents, proline as a readily available organocatalyst, reduced equivalents of H2O2, metal-free conditions, and notably short reaction times to achieve moderate-to-high yields. This promising approach encourages further exploration of the H2O2-proline system in oxidation reactions. This study's innovative approach and good results set a strong foundation for future research to expand the scope and efficiency of green oxidation processes.

An efficient green synthesis and in vitro evaluation of novel adamantane-containing 4-thiazolidinone derivatives as anticancer agents

The novel 4-thiazolidinone derivatives incorporating an adamantane moiety were synthesized in high yields through the reaction of N-adamantyl-substituted thioureas and dimethyl acetylenedicarboxylate (DMAD) using an environmentally benign method. These catalyst-free reactions were performed in an ethanol-water mixture at room temperature, with short reaction times of 3–8 minutes. The in vitro anticancer activity of the target compounds was evaluated against the A-549 human non-small cell lung cancer (NSCLC) cell line. Among the target compounds, 2b, 2c, and 2a exhibited promising cytotoxic effects, with IC50 values of 19.07, 32.92, and 63.38 µM, respectively. Additionally, the mechanisms for inhibition of cell growth and induction of apoptotic cell death were assessed using DAPI and Annexin V-FITC staining. The results indicated that the 4-thiazolidinone derivatives incorporating an adamantane moiety have significant potential for the development of anticancer therapeutics.

Bio‐Inspired Cu/Pd Bimetallic Catalysts Facilitating One‐Pot Relay Catalysis of Homo‐Couplings of Arylboronic Acids

ABSTRACTInspired by the multienzymatic relay catalysis in nature, herein, we reported a pioneering bio‐inspired Cu/Pd bimetallic composite microspheres (Cu/CMC@Pd/C) as a simple and efficient relay catalyst for the homo‐coupling of arylboronic acids. In this composite, Pd/C was encapsulated by Cu(II)‐crosslinking carboxymethyl cellulose (Cu/CMC). Cu/CMC@Pd/C microspheres were easily achieved by adding a mixture solution of Pd/C and carboxymethyl cellulose into a Cu(II) solution through an ion exchange reaction between carboxylate groups of CMC and Cu(II) ions. The morphology and composition of the as‐prepared Cu/CMC@Pd/C microspheres were well characterized using various analytical tools such as FT‐IR, XRD, XPS, SEM, TEM, elemental mapping, EDS, and ICP‐AES. The analysis indicated that the composite microspheres have a porous structure and Pd/C is uniformly distributed within the interior of the composite microspheres. The porous structure facilitates mass transfer of the substrate and increases the contact area of the catalyst, thus improving reaction efficiency. The performance of Cu/CMC@Pd/C microspheres was assessed in the homo‐coupling of arylboronic acid for the synthesis of symmetric biaryl without the need for an aryl halide as a partner. This process mimics a multienzyme catalysis through a relay Cu(I)‐catalyzed halogenation of one portion of arylboronic acid and a Pd(0)‐catalyzed Suzuki–Miyaura cross‐coupling between the in situ generated aryl halide and another portion of arylboronic acid. The results showed that this bio‐inspired Cu/CMC@Pd/C has excellent relay catalytic activity with tolerance of broad functional groups, producing the desired symmetrical biaryls in excellent yields within a short reaction time under mild conditions. Moreover, the catalyst can be easily recovered through simple filtration and still has good catalytic activity after six cycles. Consequently, this innovative pseudo‐homogeneous Cu/Pd relay catalyst emerges as a convenient and efficient alternative for the synthesis of asymmetric biaryls.

Ultrasound promoted synthesis of 2-methylthio-3H-1,5-benzodiazepines using CaFe2O4 NPs as heterogeneous catalyst and their in-vitro experimental and theoretical studies as antifungal agents

In the current study, we have developed an efficient and simple ultrasound-promoted protocol for synthesizing 2-methylthio-3H-1,5-benzodiazepine derivatives from α-oxo ketene dithioacetals using reusable CaFe2O4 nanoparticles as heterogeneous catalysts. The use of CaFe2O4 nanoparticles as catalyst under ultrasonic irradiation gave better yields in shorter reaction times in comparison to our previous synthetic strategy which used basic alumina as a solid support. The nanocatalyst was found to be applicable to diverse aromatic/heteroaromatic and cyclic ketones. In addition, the quantum mechanical calculations (DFT studies) of all the derivatives were carried out using Spartan software to determine the geometry and physiochemical properties of the derivatives and the molecular docking studies of all the optimized derivatives using Autodock Vina and Discovery Studio software to check their efficacy as antifungal agents. Based on the best docking results, In-vitro experimental studies of BDZ-13 and BDZ-19 were carried out to test their efficacy as antifungal agents.

Microwave-assisted synthesis of perovskite hydroxide-derived Co3O4/SnO2/reduced graphene oxide nanocomposites for advanced hybrid supercapacitor devices

The current article reports a facile, ultrafast, and cost-effective, solid-state microwave (MW) synthetic route for the conversion of perovskite hydroxide (CoSn(OH)6) to crystalline metal oxides (Co3O4 and SnO2) with the help of reduced graphene oxide (rGO) nanosheets. In a domestic MW oven, the Co3O4/SnO2/rGO (CSO-rGO) nanocomposite was synthesized within a quick reaction time of only 30 s. The study deeply focused on analyzing the surface morphology, metal oxide attachment on the surfaces of rGO nanosheets, the specific surface area, and the electrochemical performance of supercapacitor devices from the CSO-rGO nanocomposite. As a positive electrode for supercapacitors, the synthesized hybrid electrode displayed a good capacity (146.4C/g) and enhanced cycling stability (103.2 % after 15,000 cycles). Moreover, the corresponding aqueous hybrid supercapacitor device with MW-synthesized rGO as a negative electrode displayed a maximum energy density of 27 Wh/kg and promising cycling stability of 102.4 % after 10,000 cycles. As a whole, compared to the common time-consuming synthetic approaches, the MW-assisted synthetic approach is highly beneficial in terms of short reaction time, cost-effectiveness, and straightforwardness. The MW synthesis methodology employed in this study can be utilized for analogous composite electrodes that incorporate other layered conductive architectures in addition to metal oxides.