Letters in Organic Chemistry - Volume 20, Issue 12, 2023
Volume 20, Issue 12, 2023
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Ionic liquid Supported Quinuclidine Catalyzed Morita-Baylis-Hillman Reaction
More LessThe Morita-Baylis-Hillman (MBH) reaction is an important method for forming carboncarbon bonds between carbonyl-containing compounds and activated olefins. However, the slow reaction rate with electron-rich electrophilic partners has limited its wider use. To overcome this drawback, the effects of pyridinium-based ionic liquids mediated quinuclidine catalytic system for MBH reactions were studied. The method is simple, involving neat and open-flask conditions, and is compatible with a wide range of reagents. We offered general pyridinium-based ionic liquids-mediated quinuclidine catalysis mechanism that is responsible for the observed rate increase. The synthetic versatility of the MBH adducts is demonstrated by the synthesis of important building blocks for the natural product (-)-sitophilure. The authors anticipate that this pyridinium-based ionic liquids-mediated quinuclidine protocol could serve as a general methodology for the MBH reaction. In summary, the study presents a simple and effective method to enhance the reaction rate of the MBH reaction. The authors believe this method has the potential for broader applications and may contribute to developing new synthetic strategies for organic synthesis. We successfully recycled the catalytic system up to 7 runs without losing any catalytic activity.
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An Insight into the Correlation between Phenolic Content and In vitro Antioxidant Activity of Calocybe Indica Extracts
Calocybe indicahas been considered an essential herb, exhibiting a strong antioxidant capability. To this point, the phenolic compounds could be the primary constituent inducing such high activity. However, the phenolic-antioxidant activity correlation still needs to be understood. This study attempted to shed light on the direct linkage between phenolic compounds and antioxidant activity of the Vietnam-grown Calocybe indicafor the first time. It turns out that the total amount of phenolic content is 97.67 μg/g, which is exceptionally high in the methanol extract. Gallic acid, quercetin, quercitrin, and hesperidin account for 49.02 ± 0.18 μg/g, 15.36 ± 0.24, 18.71 ± 0.32, and 14.58 ± 0.28 μg/g of such activity, respectively. Such antioxidants result in an extraordinary performance in DPPH and ABTS evaluations. Indeed, the total antioxidant capacity ranges from 59.67±0.78 to 91.26±1.57 mg GA/g or from 75.25±0.32 to 88.17±0.64 μmol AS/g, corresponding to the contents of phenolics from 24.92 ±0.24 to 35.28 ± 0.33 mg GAE/g. Furthermore, flavonoid compounds have been quantified to range from 14.63 ± 0.17 to 23.88 ± 0.10 mg QUE/g. These results imply the prominence of Calocybe indicafor biomedical applications.
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Amine-Functionalized SBA-15 Mesoporous Silica-Anchored Ni Nanocatalyst for CO2 Hydrogenation Reaction
More LessIn this study, we successfully synthesized amine-functionalized SBA-15 mesoporous silicasupported Nickel nanoparticles (Ni NPs) and investigated their potential for CO2 transition to formic acid via high-pressure hydrogenation reaction. The metal-support interface between the Ni NPs and the amine-functionalized SBA-15 mesoporous silica was examined using various techniques, including BET, TEM, and XPS analyses. Our findings reveal a robust metal-support interaction between the NiNPs and the mesoporous silica substrate, highlighting the suitability of the catalyst for the CO2 conversion reaction. Additionally, the catalyst CAT$Ni-1 exhibited good catalytic activity over CAT$Ni-2 and CAT$Ni-3, and we were able to recycle them up to five runs with no significant reduction in catalytic activity. These results suggest that the synthesized Ni NP catalysts have the potential for large-scale CO2 conversion, contributing to the development of sustainable technologies for reducing greenhouse gas emissions.
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Development of an Efficient Process for a Diagnostic Test Agent (Bentiromide) and Identification, Synthesis, Characterization, and Control Strategy for Potential Impurities
Authors: Kiran K. Naramsetti, Chandramohan Alluri and G. Veera Raghava SharmaThe latest development studies provide a more effective and suitable process for Bentiromide (1), a diagnostic test substance. The enhanced procedure includes process modifications to get a better yield (76%) and high purity (above 99.8%) of Bentiromide (1). The current studies also outline a commercially viable method for removing important process-related impurities (A, B, C, D, E, F & G) in Bentiromide (1). During the impurity profile research, seven critical process-related impurities were found. These impurities were identified using high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS) techniques. The synthesis schemes and spectral analysis data (MS, IR, 1H NMR, and 13C NMR) were used to characterize and confirm these impurities' structures. All of these impurities sources were investigated, identified, and strict control measures were taken to reduce them to an acceptable level.
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Structural Elucidation, In vitro and In silico Biological Evaluations of New Fluorinated Chalcone Derivatives for Potential Antioxidant Activity
The newly synthesized fluorinated chalcone derivatives are observed to possess antioxidant potential. Two new fluorinated chalcone compounds were effectively synthesized using the Claisen- Schmidt condensation reaction and were recrystallized using the slow evaporation method. The single crystal structure of the compounds was determined and refined through the X-ray single crystal diffraction method. All compounds were subjected to computational structural characterization and Hirshfeld surface analysis. The compounds were then further characterized through the Ultravioletvisible (UV-Vis) spectroscopic study. The chalcone derivatives were further analysed with biological experimentation and simulation such as in vitroantioxidant (DPPH) assay, molecular docking and in silicoADMET study. The crystal packing revealed that the molecules in the compounds were linked together through the intermolecular C—H···O and C—H···π interactions. Hirshfeld surface analysis validated the presence of intermolecular interactions in crystal packing. The UV-Vis spectroscopic study revealed that the absorption wavelength of the compounds that range from 421.79 to 428.98 nm was within the visible region with the energy gap value of 2.58 to 2.62 eV. The DPPH assay disclosed weak antioxidant activity of both compounds (-31 to 20 %, 10000 μg/mL) compared to the standard ascorbic acid (94.5 %, 50 μg/mL). The binding energy of the docked complex inside the target protein, 2CAG was within the range of -7.3 to -7.5 kcal/mol. In the silico model, SwissADME predicted that the two compounds have overall good drug-like properties. Different substituents, more planar configuration and high intramolecular interactions in the crystal packing played their role in increasing the antioxidant activities, binding energy and drug likeliness of the synthesized compounds.
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Predicting the Adsorption Behavior of 6-mercaptopurine Anticancer Drug upon Polyoxazoline Nanocarrier: A Theoretical Study
Authors: Leila Rahmanifar, Fatemeh Azarakhshi and Elham MoniriPredicting the adsorption behavior of the 6-Mercaptopurine (MCP) anticancer drug upon the polyoxazolinenano-carrier was investigated using DFT and TD-DFT methods by B3LYP/6-31G* level in the gas phase and water solution. Based on the thermochemical parameters, the MCP/polymer complex in the solvent water is more stable rather than the gas phase. The adsorption energies of the MCP/polymer complex displayed that the adsorption process is exothermic. The UV/Vis absorption and IR spectra analysis were calculated to investigate the changes happening in the interaction of the MCP with the polymer. FMO analysis indicated that the energy gap (Eg) of the polymer decreased after the adsorption process. Electronic properties and MEP analysis were also studied. Based on NBO analysis and charge difference (ΔN), the charge transfer in MCP/polymer occurs essentially from the polymer to the MCP drug, which is consistent with the results of NBO analysis. It is predicted that the POZ polymer can be used as a drug delivery system for MCP drug.
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Green and Regioselective Alkylation of Dihydropyrimidinthiones through Michael Addition
Dihydropyrimidines are one of the most important heterocyclic ring systems having a serious place in medicinal and organic synthesis. In this paper, a new series of dihydropyrimidines consisting of sulfur atoms were synthesized using inorganic base K2CO3 and TBAB as an organic salt to make high polarity in reaction media. Interestingly, different 3,4-dihydropyrimidin-2(1H)-thiones reacted smoothly with various acrylic esters to afford adducts viahighly regioselective N3-Michael addition reaction was carried out at 100°C in 12 h. result: Unfortunately, the reaction failed with fumaric esters owing steric effects. Avoiding organic solvents during this reaction effectively led to the development of an economic approach. Structures of the new compounds were established on the basis of 1H NMR, 13C NMR, and IR spectral data.
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Ionic Liquid Immobilized Pd Nanocatalysts for Chemoselective Reduction of Aliphatic/Aromatic Nitro Compounds
Authors: Om Prakash, Bhawana Jangir and Vivek SrivastavaIn this work, we have successfully synthesized four types of ionic liquid-mediated Pd nanocatalysts and performed the physiochemical analysis of the developed Pd-based nanocatalysts using a transmission electron microscope (TEM), X-Ray diffraction analysis (XRD), X-ray photoelectron spectroscopy (XPS), and atomic absorption spectroscopy (AAS) analysis. The well-dispersed and fine Pd nanoparticles were recorded in the ILPdNPs-4 catalytic system. We used this catalytic system to reduce a series of aliphatic and aromatic compounds with nitro groups and developed various biologically active amine molecules. In the continuation of the same, we also reduced nitrolactone, which is considered one of the important starting materials for the synthesis of renin inhibitor aliskiren (Tekturna®, and worldwide as Rasilez®). We also completed the catalyst stability test and recycled the ILPdNPs-4 catalytic system for up to eight runs. No sign of metal leaching, Pd black formation, and agglomeration was recorded during recycling runs.
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Microwave-assisted Synthesis, Molecular Docking Study of Spirofused Heterocycles as Anti-microbial and Anthelmintic Potential
Authors: Rina Das, Dinesh K. Mehta, Sumeet Gupta, Somdutt Mujwar, Vishal Sharma, Anju Goyal, Samir Patel and Archita PatelIntroduction: The stereochemical characteristics of spirofused and their derivatives have recently attracted a great deal of interest in synthetic organic chemistry. Methods: A series of ecologically acceptable spirofused heterocycle compounds S(K1–K8) were made using a one- pot microwave irradiation and were characterized by FTIR, /sup>1HNMR, and Mass Spectroscopy. The Iodine-catalyzed Biginelli-type condensation process has been used to synthesize novel anti-microbial and anthelmintic potential spiroketals (spirofused) derivatives by using a fast, safe & effective microwave irradiation approach in order to get the product in maximum yield with lesser time consumption. Results: The compounds SK4 and SK5 showed promising antimicrobial activity against all bacterial (Bacillus subtilis, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli) and fungal strains (Candida albicans and Aspergillus niger) with MIC 6.25 μg/mL and 12.5 μg/mL. Furthermore, molecular docking studies were also simulated for compounds SK4 and SK5 to predict the specific binding mode of these compounds. Conclusion: Albendazole (Alb) was used as a reference medicine to test the anthelmintic activity of Indian adult earthworms Eisenia fetida. Compound SK4 has been found to be an effective pharmacophore.
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Volumes & issues
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Volume 22 (2025)
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Volume 21 (2024)
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Volume 20 (2023)
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Volume 19 (2022)
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Volume 18 (2021)
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Volume 17 (2020)
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Volume 16 (2019)
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Volume 15 (2018)
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Volume 14 (2017)
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Volume 13 (2016)
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Volume 12 (2015)
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Volume 11 (2014)
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Volume 10 (2013)
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Volume 9 (2012)
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Volume 8 (2011)
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Volume 7 (2010)
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Volume 6 (2009)
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Volume 5 (2008)
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Volume 4 (2007)
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Volume 3 (2006)
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Volume 2 (2005)
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Volume 1 (2004)
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