Introduction: Nitrile hydration reaction is considered one of the highly atom-economical and prominent green chemistry approaches for the synthesis of amides under aqueous medium. materials and methods: Materials and Methods Material Ammonium dihydrogen phosphate (S.d. fine chemicals), Calcium Carbonate (99+%, Sigma Aldrich), Nitric Acid (69-72%, S.d. fine chemicals), Urea (99%, S.d. fine chemicals), Lithium nitrate (99%, SRL Chemicals), Sodium nitrate (98%, Qualigens), Potassium nitrate (99%, S.d. fine chemicals). Preparation of β – Tricalcium phosphate by combustion method Appropriate weight of CaCO3 (2.0018g) and ammonium di hydrogen phosphate (NH4H2PO4, 3.45 g) was separately dissolved in 20 mL of 2M nitric acid and 25 mL of distilled water respectively. To the obtained Ca(NO3)2 solution and prepared NH4H2PO4 solution were mixed slowly and stirred. To the above solution mixture, 1.6016 g of urea was added and stirred until the solution becomes homogeneous. The furnace was heated to 500 °C prior to placing the sample for 15 min at 500 °C. The solid obtained was ground and calcined at two different temperatures (600 °C for 1h and 900 °C for 3 h). Preparation of Li/β-TCP by impregnation method Appropriate amount of lithium nitrate was added into 25 mL of distilled water and stirred for 5min to get homogeneous solution. To the above solution, as-prepared β-TCP powder was added with weight ratio of 1: 2 (TCP: LiNO3) and stirred for 1h and evaporated to dryness. The collected sample was subjected to heat treatment at 900 °C for 2 h. Similarly, K/β-TCP, Na /β-TCP and Li/HAP catalysts were also prepared by the procedure mentioned above. Catalytic Test The activity of as-prepared catalysts was screened in hydration of nitrile under reflux condition. To the benzonitrile (2.5 mmol), Li/β-TCP catalyst (0.1g) and water (7.5 mL) was added and refluxed under stirring condition (~550–600 rpm) at 125 °C for 3 h and cooldown to room temperature. After the reaction, ethanol was added and then, the catalyst was separated by filtration. The filtrate was placed on water bath to evaporate the solvent. The collected mass was purified using column chromatography with petroleum ether: ethyl acetate mixture as eluent. Melting point, FT-IR and 1H NMR spectrum was used to confirm the amide formation, and their corresponding data has been given in the supporting information. Characterization The structural information of as-prepared supports and catalysts was confirmed by powder X-ray diffraction (Cu Kα, Bruker, D8 Advanced) and Fourier transform infrared spectroscopy (JASCO FT-IR-4100 spectrometer). The amide formation was confirmed by their melting points, 1HNMR, (Bruker AVANCE III 400 MHz) and Fourier transform infrared spectroscopy (JASCO FT-IR-4100 spectrometer). Methods: Alkali metal nitrates (LiNO3, NaNO3, and KNO3) modified β-TCP were prepared by the impregnation method, and the catalytic activity of the prepared catalysts was screened in the nitrile hydration reaction. Results: Selective conversion of aromatic and heteroaromatic nitriles to respective amides has been achieved with alkali metal nitrate modified β-TCP catalysts under reflux conditions. Among the cat-alysts tested, LiNO3 impregnated β-TCP (Li/β-TCP) exhibits superior activity, whereas NaNO3 im-pregnated β-TCP (Na/β-TCP) and KNO3 impregnated β-TCP (K/β-TCP) catalysts exhibit relatively lower activity. Discussion: FT-IR and powder XRD analysis of Li/β-TCP confirmed the generation of CaO species as a new phase during the nitrate decomposition process, whereas CaO species were absent on both Na/β-TCP and K/β-TCP catalysts. Conclusion: The present study demonstrates that in situ generated CaO species on Li/β-TCP catalyst are responsible for its higher activity in thnitrile hydration reaction.
β-glucosidase enzymes play a pivotal role in the hydrolysis of glycosidic bonds, with bio-catalytic applications in glycoside synthesis, lignocellulosic biomass degradation, and the processing of glycosides. This review explores the engineering of β-glucosidase mutants to enhance their cata-lytic efficiency, substrate specificity, and stability for biocatalytic applications. It also considers hy-drolytic applications of glucosidases, such as lignocellulosic biomass valorisation, as well as syn-thetic applications via reverse hydrolysis, including the production of alkyl glycosides. Additionally, it examines rational design-led mutagenesis and directed evolution strategies to tailor enzyme activity, along with structural insights gained from molecular dynamics simulations and mo-lecular docking studies. These structural insights provide an understanding of the active-site archi-tecture, catalytic mechanism, and enzyme-substrate interactions, which are useful for the rational design of improved glucosidase variants. This review underscores the synergistic role of mutagenesis studies and structural analysis in optimizing glucosidases for efficient and sustainable biocatalytic applications, paving the way for innovative applications in green chemistry.
Widespread use of organic dyes and nitrophenols in paint, textile, chemi-cal, or pharmaceutical industries leads to water pollution. Reductive degradation using metal cata-lysts has emerged as an effective approach. In line with this, the current work reports the synthesis and characterization of polyaniline-supported nickel acetate (PANI-Ni), which successfully cata-lyzed the reduction of p-nitrophenol, Methylene Blue (MB), and Rhodamine B (RhB) with recovery and recyclability. PANI-Ni catalyst was prepared by adding polyaniline base (PANI) to the aqueous solu-tion of nickel acetate tetrahydrate, followed by simple filtration and washing. Finally, it was dried under vacuum to obtain the PANI-Ni. The amount of Ni loading was quantified using Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP-AES). The catalyst was well characterized using Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy-energy dis-persive X-ray analysis (SEM-EDX), and X-ray powder diffraction (XRD). The catalytic efficiency of the PANI-Ni was tested in the reduction of p-nitrophenol (p-NP) and reductive degradation of organic dyes like Methylene Blue (MB), and Rhodamine B (RhB) in the presence of sodium boro-hydride (SB) as the hydrogen source. The recovered catalyst was characterized using X-ray photo-electron spectroscopy (XPS) and Transmission electron microscopy (TEM). The catalytic activity of PANI-Ni was first evaluated for the reduction of p-NP, and it was found that complete reduction was achieved within 3 min., as monitored via UV absorption analysis. The scope of the catalyst was further explored for the degradation of MB and RhB. In both cases, high catalytic efficiency was observed. The catalytic degradation rate was found to be dependent on the pH of the reaction medium and on the amount of catalyst. PANI-Ni catalyst showed consistent activity over six cycles in the degradation of MB with the presence of SB. Recovered PANI-Ni showed the presence of Ni (0) as established by TEM and XPS studies. These results demonstrate that PANI-Ni is a highly effective and promising catalyst for the reductive degradation of organic dyes. The cheaper cost, high efficiency, and recyclability further underscore its potential for sustainable water remediation.
Manganese-catalyzed N-formylation of aniline using formic acid (HCOOH) represents a notable advancement in formanilide synthesis. This method offers a safer and more manageable alternative to conventional formylation methods, which rely on toxic carbon monoxide (CO) gas. The strategy utilizes HCOOH as a convenient and environmentally friendly surrogate for CO. Manganese catalysts are employed to promote selective C-N bond formation under mild con-ditions. The process achieves moderate to excellent yields across a broad range of formanilides, demonstrating good functional group tolerance and efficiency. A manganese-catalyzed protocol was developed for the efficient N-formylation of ani-lines using formic acid as a surrogate for CO. Optimization studies revealed that MnCl24H2O (5 mol%) with Na2CO3.H2O (2 equiv.) in DMF at 130°C under nitrogen for 20 h provided formanilide in 98% yield. Various reaction parameters, including catalyst type, base, solvent, temperature, and time, were systematically optimized. The method exhibited a broad substrate scope, tolerating sev-eral electron-donating and halogen-substituted groups. However, ortho-substituted anilines, nitroan-ilines, N-alkylated amines, and certain heterocycles showed low to no reactivity under the optimized conditions. This study highlights the versatility of manganese catalysts in sustainable synthesis. It marks a significant development in the production of CO-free formanilide via N-formylation of aniline using formic acid.
The organometallic chemistry associated with the metal aryloxide compounds is growing rapidly. Research has focused on the ligands'; reactivity, for example, the insertion chemistry of the M-OAr bonds, and on the organometallic reactivity that can be supported by aryloxide ligation. Species of titanium bonded to aryloxo ligands are often used as base compounds for material engineering, catalysts, or initiators for different kinds of polymerization processes, and biodegradable materials. A tetrakis(4-bromphenoxo)titanium(IV), Ti(OC6H4Br-4)4, complex has been synthesized using titanium tetrachloride with four moles of 4-bromophenol in carbon tetrachloride. Double phenoxide of composition Na2[Ti(OC6H4Br-4)6] was prepared by reacting Ti(OC6H4Br-4)4 in methanol with sodium bromophenoxide dissolved in the same solvent in a 1:2 (titanium: alkali metal) molar ratio. Reactions of Ti(OC6H4Br-4)4 with pyridine, diethylamine, and triethylamine were carried out in a 1:2 molar ratio, while with bidentate ligands, namely 1,10-phenanthroline and 2,2/-bipyridyl, reactions were carried out by mixing them in the equimolar ratio in dry benzene. The chelates with chelating agents such as benzoin, salicylaldehyde, and 2-hydroxyacetophenone were prepared with Ti(OC6H4Br-4)4 taken in methanol with a bimolar amount of chelating agent. Ti(OC6H4Br-4)4 is also characterized using elemental analysis, IR, 1H NMR, mass spectrometry, X-ray diffraction studies, and thermal analysis. The 4-bromophenol ligand binds to metal via the oxygen of the phenoxy group, and the compound has been assigned a dimeric structure bridging through phenoxy groups. Moreover, the complex Ti(OC6H4Br-4)4 forms a double phenoxide, behaves as a Lewis acid, and forms mixed chelate complexes.
Titanium dioxide (TiO2) has long been regarded as the perfect nano-material because of its great stability, affordability, and non-toxicity, which make it safe for use by humans and the environment. TiO2's broad band gap limits its use in photocatalysis under visible light. When non-metallic elements are added to the TiO₂ lattice, new energy levels above the TiO2 valence band are introduced, which reduces the band gap energy and increases its photocatalytic activity in the visible part of the light spectrum. In this work, a single-step sol-gel method is used to prepare C,N-doped TiO2 nanoparticles using chicken egg white as a precursor for both carbon and nitrogen. The prepared nanoparticles were used to degrade benzoic acid, which is considered an emerging pollutant in wastewater. The degradation of benzoic acid was carried out using three different light sources: UV-C light, solar light, and visible light. Characterization techniques such as X-ray diffraction, Ultraviolet-visible diffuse reflectance spectroscopy, Scanning Electron Microscopy with Energy Dispersive X-ray analysis, and Trans-mission Electron Microscopy with Selected Area Electron Diffraction confirm the presence of car-bon and nitrogen in TiO2 nanoparticles, with sizes ranging between 13 and 15 nm. XRD confirms the presence of the anatase phase of TiO2 nanoparticles, which is crystalline in nature. Using a green sol-gel method with chicken egg white as a dual source of carbon and nitrogen, C, N-doped TiO2 nanoparticles were successfully synthesized. The characterization con-firmed the anatase phase with particle sizes ranging from 13 to 15 nm and effective dopant incorpo-ration, which narrowed the band gap and improved visible-light absorption. Compared to undoped TiO₂, the photocatalytic activity of the doped TiO2 showed significant enhancement in degrading benzoic acid under visible and solar light. This improvement is credited to the formation of mid-gap states that foster improved charge separation and light utilization. The research illustrates a hopeful method for treating wastewater through sunlight-driven photocatalysis. A degradation study of benzoic acid was carried out with TiO2 P-25, which degraded only 5% in the visible region, while C,N-doped TiO2 degraded benzoic acid up to 45% under visible light, which was further enhanced by 10–12% with the addition of H₂O₂, thus indicating the narrow-ing of the TiO2 band gap and increased photocatalytic activity in the visible part of the light spec-trum. The kinetics of all the reactions followed pseudo-first-order behavior. Degradation study of benzoic acid was carried out with TiO2 P-25 which was only 5 % in visible region while C,N-doped TiO2 degraded benzoic acid up to 45 % in visible light which was again enhanced 10 – 12 % by addition of H2O2. Thus, indicating narrowing of TiO2 band gap and increasing its photocatalytic activity towards visible part of light spectrum. The kinetics of all the reactions follow pseudo-first-order
Efficient, durable, and low-cost bifunctional electrocatalysts for the hydrogen and oxygen evolution reactions (HER/OER) are essential for sustainable water elec-trolysis. This work aimed to develop a green, scalable, ambient-air synthesis of carbon nanotube-confined NiFe alloy nanoparticles on carbon cloth (FeNi₃@CNT/CC) that delivers high HER/OER activity and stability in alkaline media. A one-step laser-scribing strategy was used under ambient air to fabricate FeNi₃ nanopar-ticles encapsulated by graphitic carbon nanotubes on carbon cloth, yielding a hierarchical porous architecture. Electrochemical performance for HER and OER in alkaline electrolyte was evaluated by polarization, Tafel analysis, and durability testing at constant current. FeNi₃@CNT/CC exhibited low overpotentials of 155 mV (HER) and 297 mV (OER) at 10 mA cm⁻², with favorable Tafel slopes of 149 and 56 mV dec⁻¹, respectively. The catalyst re-tained >95% of its initial activity after 15 hours of continuous operation, outperforming most re-ported transition metal-based analogues in long-term stability. The high activity and durability arose from synergistic bimetallic electronic modulation (Fe–Ni), nanoscale encapsulation by conductive graphitic shells that suppressed dissolution and ag-glomeration, and a hierarchical porous framework that accelerated mass transport and electron con-duction. Beyond performance, the ambient laser process obviated the need for inert-gas protection and markedly reduced energy consumption compared to tube-furnace routes. This study has demonstrated a green, cost-effective, and scalable route to robust car-bon-shelled bifunctional electrocatalysts. The ambient-air laser-scribing strategy has offered a ver-satile platform for synthesizing advanced energy materials with high activity and stability for alka-line water splitting.
Pollution of ecosystems by hazardous organic dyes and toxic byproducts from industrial effluents of the textile, cosmetic, and pharmaceutical industries is a growing environ-mental and public health concern. Thus, studies have focused on finding effective methods for the degradation of hazardous organic dyes. The most promising technique is the use of nanoparticles as a catalyst. Specifically, silver nanoparticles (AgNPs) have been extensively researched for their ef-fective treatment of wastewater. Methodology: In this study, five leaf varieties of Cocos nucifera, namely Red Kundira, Gon thambili, Thaembili, Ran thaembili, and Brown Kundira, were used to synthesize AgNPs. These AgNPs were then employed to perform photocatalytic degradation studies using common industrial dyes, such as methyl orange (MO) and para-nitrophenol (PNP), as well as cytotoxicity assays. The photocatalytic activity of AgNPs demonstrated faster degradation at a concentration of 267 ppm in the presence of sunlight and sodium borohydride (NaBH4), while 4000 ppm AgNPs also exhibited considerable degradation under the same conditions. The catalytic activity of the AgNPs was evaluated using the degradation of PNP in the presence of NaBH4, which showed notable degradation. The highest degradation was observed with Gon thaembili_AgNP (GT_AgNP). Cytotoxicity screening using two different concentrations of AgNPs (800 ppm and 240 ppm) showed 100% viability against Artemia salina. It can be concluded that AgNPs synthesized from the extracts of coconut leaves may be utilized in the bioremediation of environmental pollutants. The photocatalytic activity of AgNPs was studied using a common industrial dye, methyl orange (MO), which showed faster degradation in 267 ppm AgNPs in the presence of sunlight and sodium borohydride (NaBH4), while 4000 ppm AgNPs also showed a considerable degradation under the same conditions. PNP degradation using NaBH4 was used to test the catalytic activity of the AgNPs, and it showed notable degradation. The highest degradation is observed in Gon thaembili AgNP. The cytotoxicity screening using two different concentrations of AgNPs showed 100% viability against Artemia salina.
A class of desirable hybrid motifs seen in a number of significant medications includes indoles and coumarins, known as 3-((1H-indol-3-yl)(phenyl)methyl)-4-hydroxy-2Hchromen- 2-ones. However, the development of the indole coumarins synthesis technique has many benefits. We wish to investigate the significance of 3-((1H-indol-3-yl)(phenyl)methyl)-4-hydroxy- 2H-chromen-2-one's molecules and develop a productive method that employs a wider variety of benzaldehydes, 4-hydroxycoumarin, and indoles that react under mild conditions. As a catalyst, iodine has several advantages over traditional reagents, such as high yields and purity, no toxicity, broad functional group tolerance and simplicity of workup. Molecular iodine has been demonstrated to be a mild, cost-effective and efficient catalyst for the synthesis of 3-((1Hindol- 3-yl)(phenyl)methyl)-4-hydroxy-2H-chromen-2-one molecular analogs. Polar protic solvents, such as ethanol, have been found to decrease the synthesis of indole coumarins, and the limited solubility of 4-hydroxycoumarin in nonpolar solvents explains why nonpolar solvents are unwilling to produce biscoumarins and bisindoles. In conclusion, we discovered a sustainable and effective way to synthesize derivatives of hybrid indole coumarins. Because it employs iodine as a traditional catalyst, it has a clean reaction profile, fast reaction times, and is reasonably priced, the process is truly environmentally friendly.
A new heterocyclic oxovanadium(IV) quinoxaline Schiff base complex, ((VO)L2) with a square pyramidal geometry around vanadium (IV) (where L' is the azomethine Schiff base formed by the condensation of 3-hydroxyquinoxaline-2-carboxaldehyde with 2-amono-phenol), has been prepared and characterized. The elemental analysis, molar conductance, magnetic measurement, FT-IR, UV-Visible, EPR, TG-DTA-DTG and cyclic voltametric studies confirmed the coordination of oxovanadium with the two molecules of ligands. Catalytic activity of the oxo-vanadium complex was tested in the liquid phase oxidation of cyclohexene with H2O2 as the oxi-dant. The catalyst has a turn over frequency 251 h-1 with 7.50 × 10-6 mol catalyst, 18.170 × 10-3 mol of H2O2 at 80°C and the cyclohexene conversion was estimated to be 19.10% with product selectiv-ity of cyclohexene oxide (6%), cyclohexanol (34%) and cyclohexanone (60%). Catalytic results yield cyclohexenol and cyclohexenone as the major products, along with a minor cyclohexene oxide product. These results suggest both the allylic C−H bond and the olefinic C=C bond activation dur-ing the process of catalysis by the complex. Condensation reaction of 3-hydroxyquinoxaline-2-carboxaldehyde and 2-aminophenol in the presence 2 or 3 drops of concentrated HCl resulted in the formation of the azomethine Schiff base. The complexation of the Schiff base with vanadium and the geometry of the resulting complex were determined by employing various physico-chemical measurements like elemental analysis, molar conductance, magnetic measurement, FT-IR, UV-Visible, EPR, TG-DTA-DTG and cyclic voltametry. Catalytic property of the synthesized oxovanadium(IV) quinoxaline Schiff base com-plex in cyclohexene oxidation was studied in a simple glass reactor and the progress of the reaction was monitored gas chromatographically. A square-pyramidal oxovanadium(IV) quinoxaline Schiff base complex, ((VO)L2), was synthesized and characterized. Catalytic oxidation of cyclohexene with the complex gave cyclohex-enol and cyclohexenone as the major products, along with minor cyclohexene oxide. The experi-mental findings predict the formation of both allylic C−H bond and the olefinic C=C bond activation during catalysis. Conversion of cyclohexene, product selectivity and H2O2 efficiency were calcu-lated under various reaction conditions. A new square-pyramidal oxovanadium(IV) quinoxaline complex with the general for-mula (VOL2) was prepared and characterized by elemental analysis, molar conductance, magnetic measurement, FT-IR, UV-Visible, EPR, TG-DTA-DTG and cyclic voltametric studies. The utility of the oxovanadium(IV) complex as a catalyst in the oxidation of cyclohexene in acetonitrile with H2O2 was studied under various reaction conditions. Catalytic observations predicted the formation of cyclohexenol and cyclohexenone as the major reaction products, along with minor cyclohexene oxide. Cyclohexene conversion, product selectivity and H2O2 efficiency values were calculated for this reaction under various conditions. Under the optimized reaction conditions, the oxovanadium complex catalyzed the cyclohexene oxidation with 19.10 % conversion with a turnover frequency of 251 h-1. Catalytic activity of a new oxovanadium (IV) quinoxaline Schiff base complex in the liquid phase oxidation of cyclohexene with H2O2 as oxidant was studied. Under the optimized reaction conditions at 30 % HP (18.70 × 10^(-3) mol), temperature (80 °C), time (2 h), catalyst (7.50 × 10^(-6) mol), and cyclohexene (1.97 × 10^(-2) mol) and acetonitrile (30 mL), the complex showed 19.10 % cyclohexene conversion.
The breakdown of organic contaminants from wastewater can be facilitated by metal-organic frameworks, which are three-dimensional coordination polymers with a large number of active sites and an organised porosity architecture. Using Zn, Cu, Mn, Cd, and Cr metal salts together with 1,4- benzenedicarboxylic acid as the organic linker, three novel trimetallic metal-organic frameworks; ZnCuMnBDC MOF, ZnCdMnBDC MOF, and ZnCrMnBDC MOF were developed in this study using a solvothermal strategy. They have been characterised using various analytical techniques, including FT-IR, ultraviolet/visible diffuse reflectance spectroscopy (UV-DRS), X-ray powder diffraction studies, N2 adsorption– desorption analysis, scanning electron microscopy (SEM) with energy-dispersive spectroscopy (EDS), and X-ray photoelectron spectroscopy (XPS). These MOFs are explored as catalysts for the photocatalytic degradation of Congo Red dye. Moreover, the catalytic activity of the as-prepared catalysts was assessed in terms of the degradation efficiency. Among these MOFs, ZnCrMnBDC MOF exhibited the highest performance, achieving 98.4% degradation of Congo Red, followed by ZnCdMnBDC MOF at 88.0% and ZnCuMnBDC MOF at 85.89% within 30 minutes of irradiation. These findings underscore the potential of MOFs as effective photocatalysts for environmental remediation under visible light, offering a promising avenue for wastewater treatment. These results highlight that MOFs are potentially efficient photocatalysts for environmental remediation in the presence of visible light, providing an effective wastewater treatment method.
Many important drugs contain a class of preferred motifs called bisindoles. The development of synthetic approaches for bis(indolyl)methanes (BIMs) offers numerous advantages. However, most methods for synthesizing BIM derivatives require metal catalysts. This study aimed to synthesize bisindoles via oxidative cleavage of 1,2-diols using periodic. acid. For the synthesis of bisindoles via oxidative cleavage of 1,2-diols, periodic acid was used. It is a gentle, reasonably priced, and effective testing agent for the synthesis of bisindole analogs from a range of 1,2-diols. Aldehydes were produced by the in situ oxidation of 1,2-diols by periodic acid, and they reacted with indoles to generate a range of bisindoles. The HIO3 generated in situ from periodic acid accelerated the reaction. The structures of the compounds were confirmed by NMR (1H and 13C), high-resolution mass spectrometry (HRMS), and elemental analysis using a CHNSO analyzer. A variety of BIMs derivatives were produced by oxidatively breaking down 1,2-diols using periodic acid. The appealing aspects of this procedure include its high yield, rapid response time, and catalyst-free conditions. In this study, a productive and sustainable method for creating BIMs derivatives is presented. The procedure is genuinely green since it uses periodic acid as an oxidizing agent rather than a conventional catalyst, has a clean reaction profile, quick reaction times, and is inexpensive.
Introduction: A four-coordinate ruthenium(II) quinoxaline Schiff base complex with formula [Ru2LCl2].H2O has been synthesized and characterized. The hydrogenation of benzene and toluene using this complex as a catalyst was studied in a semi-batch reactor. Methods: At 60ºC with 2.82 × 10–6 mol catalyst and 30 bar hydrogen pressure, turnover fre-quencies 7362 h−1 and 5873 h−1 have been found for the reduction of benzene (0.34 mol) and toluene (0.28 mol), respectively. i Results: Both partial and complete reduction occurs with more selectivity for the formation of completely reduced products. The initial rate approach was used to study the kinetics of benzene hydrogenation, and the reaction was discovered to be first order with regard to benzene and the catalyst, while following Michaelis-Menton kinetics with respect to dihydrogen Conclusion: This kinetic data proposed an intermediate hydride/dihydrogen complex as the catalytically active species which controls the overall hydrogenation rate.
Introduction: The present study aims to discuss the synthesis of various spiropyrano- oxoindole derivatives through a reaction involving isatin, malononitrile, and a CH-acid source in the presence of vitamin B12. Materials and Methods: Eco-friendly solvents were utilized to synthesize the spiro-pyranooxoindole, resulting in high yields of all synthesized heterocyclic systems. Isatin and malononitrile were reacted with β-dicarbonyls as CH-acids in the presence of vitamin B12. Results: The results indicate that vitamin B12 is highly effective in generating spiro-pyranooxoindole derivatives. All synthesized compounds closely match previously reported compounds. Conclusion: In conclusion, a new and effective method for synthesizing spiro-pyrano-oxoindole has been demonstrated using vitamin B12 as a biocatalyst.
Biocatalysis is an approach to green chemistry. A crucial step in the synthesis of organic compounds is the reduction of aldehydes and ketones to secondary alcohols. The use of a biocatalyst, such as enzymes or entire cells, has not affected this process.. It offers great selectivity, high specificity, and an environmentally friendly approach to synthesis. Dried baker's yeast mediates the conversion of optically active alcohols from aromatic aldehydes and ketones. This work highlights applications of Baker's yeast in synthesizing pharmaceutical intermediates and chiral building blocks, demonstrating its practical relevance. Sustainable technology is based on the ideas and measurements of sustainable development and green for good enantioselectivity across several organic solvents.
Zinc oxide (ZnO) is an inorganic compound with unique physicochemical characteristics that make it versatile and suitable for various applications, especially in the form of nanoparticles (NPs). ZnO nanoparticles (ZnO NPs) exhibit distinct properties and are produced through diverse techniques, making them valuable for applications ranging from consumer goods to medical and catalytic uses. The increasing popularity of ZnO NPs is driven by novel synthesis methods that allow for modification of chemical composition and control over size and shape, thereby enhancing their properties and expanding their applications. The catalytic activity of ZnO NPs is influenced by parameters such as oxophilicity, large surface area, amphoteric nature, and the zinc cation's ability to approach activated starting material supports, making them viable heterogeneous catalysts for a variety of applications. Various analytical techniques, including X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) analysis, atomic force microscopy (AFM), and many more, are used to characterize the nanoparticles. This article explores various synthesis methods and characterization techniques and focuses on the catalytic activities of ZnO NPs.
Introduction: A binuclear azomethine quinoxaline Schiff base copper (II) complex, [Cu2LCl2], having square-planar environment around each copper (II), has been synthesized. Method: The coordination of the azomethine quinoxaline Schiff base with copper (II) and its structure was studied by various physicochemical and spectroscopic measurements. Results: Catalytic activity of this complex in phenol hydroxylation reaction has been examined using H2O2 as a green oxidant. Conclusion: Catalytic reaction conditions were optimized and under these conditions, 18.32 % conversion of phenol has been obtained for this catalyst
Background: For catalyzing carbon-carbon and carbon-heteroatom bond formation reactions, core-shell nanocomposites have attracted particular attention as invincible heterogeneous catalysts. Heterocyclic motifs like pyrazole have been used in anticancer drugs. Moreover, DNA repair enzymes are also an efficient target for developing potential anticancer therapies. Methods: Novel core-shell nanocomposite coal fly ash @CuO has been produced by loading the precursor Cu(NO3)2.3H2O on a thermally and chemically activated Coal Fly Ash (CFA) core. Triton X-100 surfactant was used to increase the uniform adhesive coating of the CuO shell on the fly ash core. The structure and physicochemical properties of the composite were elucidated through techniques, such as Fourier-Transform Infrared Spectroscopy (FTIR), X-ray powder diffraction (XRD), Field Emission Scanning Electron MicroscopyEnergy-Dispersive X-ray spectroscopy (FE-SEM and EDAX), Transmission Electron Microscopy, Selected Area Electron Diffraction (TEM and SEAD), and Brunauer-EmmettTeller (BET) surface analysis. Then, the catalytic efficiency of CFA@CuO was checked for the synthesis of bis-pyrazole derivatives. Furthermore, we also executed docking simulations between 1QZQ and bis pyrazole molecules to assess the affinity and binding orientation of the ligand. Results: Compared to synthesized CuO nanoparticles, the catalytic activity of CFA@CuO could be found promising as it offers high yield and purity of bis-pyrazole derivatives. After the completion of the reaction, the catalyst was separated and recycled. It was found that the yield of this catalyst remained unchanged even after four consecutive runs. A docking simulation was performed between 1QZQ and bis-pyrazole derivatives, proving that pyrazoles are a better source for inhibiting selectively tyrosyl DNA phosphodiesterase I. Conclusion: Herein, we report a convenient and efficient practical protocol for the preparation of 4, 4-(arylmethylene)-bis (3-methyl-1-phenylpyrazol-5-ols) and its derivatives using Tandem- Knoevenagel-Michael cyclocondensation of aromatic aldehydes, ethyl acetoacetate, and phenyl hydrazine using CFA@CuO nanocomposite as a heterogeneous nanoscale and recyclable catalyst. A molecular docking study concluded that 4’-(4- nitrophenylmethylene) bis(3-methyl-1phenyl-1H-pyrazol-5-ols) is a better inhibitor of lead against 1QZQ among all synthesized derivatives, suggesting it a potent hydrophobic lead drug candidate as phosphodiesterase inhibitor
Introduction: The gold-catalyzed benzannulation reaction of oxo-alkynes with al-kenes or alkynes is one of the important and unique reactions in gold-catalyzed organic trans-formations. Methods: In this manuscript, many facets of this reaction have been discussed concerning reac-tivity and selectivity, along with a new self-benzannulation process. The scope of this chemistry was extended to construct a phenanthrene moiety. Results: In addition, a palladium-gold dual catalytic arylation of isobenzopyrylium salts using arene-diazonium salts as an aryl group source and a one-pot isoquinoline synthesis is reported for the first time. Conclusion: Moreover, a conductance measurement experiment was performed, which supports the formation of ionic species, most likely the isobenzopyrylium auric ate complex as an inter-mediate formed during the reaction process.
Being a greenhouse gas, methane is a threat to biodiversity. Hence, the utilization of methane by converting it into a valuable chemical like methanol is one of the most promising re-actions. To solve that problem, a large number of studies have been performed on methane-to-methanol conversion (MTM process). Still, to date, the production of methanol from methane on an industry scale is a crucial challenge. After a thorough study, in this review article, only those reported methods, which produce a satisfactory yield of methanol using a large variety of cata-lysts like natural, heterogeneous, non-thermal plasma, nanoparticles fixed in solid bed, etc., have been briefly discussed. To investigate minutely, the reason behind the inefficiency of each type of catalyst in producing methanol on a large scale has been analyzed, and a comparison among the activities of different catalysts has been made. Herein, catalysts with comparatively better ef-ficiency under ambient temperature and pressure have also been highlighted. With the hope of producing methanol on a large scale, some basic concepts of future planning strategies for de-signing more suitable reaction systems are also proposed in this study
