Green Chemical Synthesis Research Articles

Uses of organometallic compounds in chemical processes

This review is proposed to address knowledge of organometallic compounds (OMC) in chemical applications and show these compounds' depth scope in different scientific studies. This review is based on outlining the gap between the traditional preparations and green chemistry synthesis of organometallic materials purposes in the experimental section of a researcher's papers. The most comparative research considers the drawbacks of organometallic compounds, including their applications in industrial, clinical, drug forms, and chemical reactions. However, many organometallic compounds are inherently poisonous. The most general challenge is producing alternative substances to creative green organometallic compounds, specifically in drug formulations systems. A wide range of chemical reactions have been investigated and formulated new organometallic properties this may be associated with an increased level of enhancement health systems. This study aims to determine the importance of organometallic compound in many path ways in various articles and confirmed how papers trying to characterize new organometallic substances in various chemical processes. Particular interest is given to knowledge synthesis OMC in medicine and industrially.

Cu2O nanoparticle-catalyzed tandem reactions for the synthesis of robust polybenzoxazole.

We report the synthesis of Cu2O nanoparticles (NPs) by controlled oxidation of Cu NPs and the study of these NPs as a robust catalyst for ammonia borane dehydrogenation, nitroarene hydrogenation, and amine/aldehyde condensation into Schiff-base compounds. Upon investigation of the size-dependent catalysis for ammonia borane dehydrogenation and nitroarene hydrogenation using 8-18 nm Cu2O NPs, we found 13 nm Cu2O NPs to be especially active with quantitative conversion of nitro groups to amines. The 13 nm Cu2O NPs also efficiently catalyze tandem reactions of ammonia borane, diisopropoxy-dinitrobenzene, and terephthalaldehyde, leading to a controlled polymerization and the facile synthesis of polybenzoxazole (PBO). The highly pure PBO (Mw = 19 kDa) shows much enhanced chemical stability than the commercial PBO against hydrolysis in boiling water or simulated seawater, demonstrating a great potential of using noble metal-free catalysts for green chemistry synthesis of PBO as a robust lightweight structural material for thermally and mechanically demanding applications.

Unique functionalities of carbon shells coating on ZnFe2O4 for enhanced photocatalytic hydroxylation of benzene to phenol

Hydroxylation of benzene to phenol over a photocatalyst is a green approach toward phenol production. ZnFe2O4 (ZFO) with an intrinsic peroxidase-like catalytic behavior toward H2O2 activation is an emerging photocatalyst for benzene hydroxylation reaction; however, its catalytic performance is greatly limited by the fast charge recombination, inevitable metal leaching and hydrophilic surface structure. Herein, the encapsulation of ZFO by carbons (ZFO@C) is an effective solution to address these issues. The carbons conformably coating on ZFO not only protect them from corrosion and metal leaching, but also enable the generation of a strong electronic contact between them to facilitate charge separation. In addition, the carbons also increase the surface affinity for benzene adsorption. As a result, ZFO@C exhibited a significant enhanced photocatalytic activity and durability for phenol synthesis. Furthermore, ZFO@C with carbon derived unique functionalities will have a broad application in photocatalytic green synthesis of fine chemicals.

Activated Carbon from Palm Date Seeds for CO2 Capture.

The process of carbon dioxide capture and storage is seen as a critical strategy to mitigate the so-called greenhouse effect and the planetary climate changes associated with it. In this study, we investigated the CO2 adsorption capacity of various microporous carbon materials originating from palm date seeds (PDS) using green chemistry synthesis. The PDS was used as a precursor for the hydrochar and activated carbon (AC). Typically, by using the hydrothermal carbonization (HTC) process, we obtained a powder that was then subjected to an activation step using KOH, H3PO4 or CO2, thereby producing the activated HTC-PDS samples. Beyond their morphological and textural characteristics, we investigated the chemical composition and lattice ordering. Most PDS-derived powders have a high surface area (>1000 m2 g−1) and large micropore volume (>0.5 cm3 g−1). However, the defining characteristic for the maximal CO2 uptake (5.44 mmol g−1, by one of the alkaline activated samples) was the lattice restructuring that occurred. This work highlights the need to conduct structural and elemental analysis of carbon powders used as gas adsorbents and activated with chemicals that can produce graphite intercalation compounds.

Advances in the Application of Nanocatalysts in Photocatalytic Processes for the Treatment of Food Dyes: A Review

The use of food additives (such as dyes, which improve the appearance of the products) has become more prominent, due to the rapid population growth and the increase in demand for beverages and processed foods. The dyes are usually found in effluents that are discharged into the environment without previous treatment; this promotes mass contamination and alters the aquatic environment. In recent years, advanced oxidation processes (AOPs) have proven to be effective technologies used for wastewater treatment through the destruction of the total organic content of toxic contaminants, including food dyes. Studies have shown that the introduction of catalysts in AOPs improve treatment efficiency (i.e., complete decomposition without secondary contamination). The present review offers a quick reference for researchers, regarding the treatment of wastewater containing food dyes and the different types of AOPs, with different catalyst and nanocatalyst materials obtained from traditional and green chemical syntheses.

A lipase/poly (ionic liquid)-styrene microspheres/PVA composite hydrogel for esterification application

Enzymes are particularly attractive as biocatalysts for the green synthesis of chemicals and pharmaceuticals. However, the traditional enzyme purification and separation process is complex and inefficient, which limits the wide application of enzyme catalysis. In this paper, an efficient strategy for enzyme purification and immobilization in one step is proposed. A novel poly (ionic liquid)-styrene microsphere is prepared by molecular design and synthesis for adsorbing and purifying high activity lipase from fermentation broth directly. By optimizing the surface morphologies and charge of the microspheres, the enzyme loading is significantly improved. In order to further stabilize the catalytic environment of lipase, the resulting lipase/poly (ionic liquid)-styrene microspheres are immobilized in physical crosslinking hydrogel to obtain a complex lipase catalytic system, which can be prepared into various shapes according to the requirements of catalytic environment. In the actual catalytic reaction process, this complex lipase catalytic system exhibits excellent catalytic activity (6314.69 ± 21.27 U mg−1) and good harsh environment tolerance compared with the lipase fermentation broth (1672.87 ± 36.68 U mg−1). Under the condition of cyclic catalysis, the complex lipase catalytic system shows the outstanding reusability (After 8 cycles the enzymatic activity is still higher than that of the lipase fermentation broth) and is easily separated from the products.

Platinum Nanowire Based Electrodes with Boosted Catalyst Utilization for Efficient Hydrogen Production in PEM Electrolyzer Cells

Due to the limited triple phase boundary (TPB) sites caused by the intrinsically low electrochemical active surface area (ECSA) of catalysts and poor interfacial contact between a catalyst layer and a porous transport layer, high noble metal catalyst loadings are generally required to achieve high-efficiency hydrogen production in low-temperature proton exchange membrane electrolyzer cells (PEMECs). Our recent studies have demonstrated that direct deposition of platinum nanoparticles onto 25-µm-thick titanium liquid/gas diffusion layers (LGDLs) can significantly reduce the cathode catalyst waste.1-3 To further lower the cost of both catalysts and electrode fabrication, for the first time, we develop a green chemical synthesis approach at room temperature to fabricate ultrathin electrodes composed of platinum nanowires (PtNW) in-situ grown on thin titanium LGDLs.4 Our developed high-speed micro-scale visualization system reveals that ultrathin Pt nanowires display more uniform reaction sites and favorable bubble detachment compared to conventional Pt nanoparticles. Impressively, when integrated into a PEMEC, the PtNW electrode with a low catalyst loading of 0.2 mg cm−2 can achieve a low cell voltage of 1.643 V and high efficiency of 90.08% at 1000 mA cm−2, which significantly surpasses conventional electrodes with high loadings. Such performance enhancement is mainly attributed to the high ECSA of catalysts, favorable hydrogen bubble detachment, and good conductivity of the whole electrode. References Z.Y. Kang, G.Q. Yang, J.K. Mo, Y.F. Li, S.L.Yu, D.A. Cullen, S.T. Retterer, T.J. Toops, G. Bender, B.S. Pivovar, J.B. Green Jr, and F.Y. Zhang. "Novel thin/tunable gas diffusion electrodes with ultra-low catalyst loading for hydrogen evolution reactions in proton exchange membrane electrolyzer cells." Nano Energy. 47, 434-441 (2018).J.K. Mo, Z.Y. Kang, S.T. Retterer, D.A. Cullen, T.J. Toops, J.B. Green Jr, M.M. Mench, and F.Y. Zhang. “Discovery of true electrochemical reactions for ultrahigh catalyst mass activity in water splitting.” Science Advances, 2, 1600690 (2016).Z.Y. Kang, J.K. Mo, G.Q. Yang, S.T. Retterer, D.A. Cullen, T.J. Toops, J.B. Green Jr, M.M. Mench, and F.Y. Zhang. “Investigation of thin/well-tunable liquid/gas diffusion layers exhibiting superior multifunctional performance in low-temperature electrolytic water splitting.” Energy & Environmental Science, 10, 166-175 (2017).Z.Q. Xie, S.L. Yu, G.Q. Yang, K. Li, L. Ding, W.T. Wang, D.A. Cullen, H.M. Meyer III, S.T. Retterer, Z.L. Wu, P.X. Gao and F.Y. Zhang. "Ultrathin platinum nanowire based electrodes for high-efficiency hydrogen generation in practical electrolyzer cells." Chemical Engineering Journal. 410, 128333 (2021).

Highly selective photocatalytic synthesis of ethylene-derived commodity chemicals on BiOBr nanosheets

The synthesis of ethylene-derived commodity chemicals is an important process in industry. However, the current manufacturing process is energy-intensive and contributes a significant amount of greenhouse gas emissions. Photocatalytic conversion of ethylene to target products is a more sustainable and green alternative. In this work, we designed a bromide-mediated photocatalytic approach for highly selective synthesis of ethylene oxide or ethylene glycol from ethylene. The bromine/hypobromous acid (Br2/HOBr) generated in photocatalytic process are effective active species for conversion of gaseous ethylene to liquid intermediates, bromoethanol and dibromoethane. These intermediates were further converted to ethylene oxide or ethylene glycol via a facile alkali treatment in different temperatures, giving rise to a high selectivity of 92% and 100%, respectively. Interestingly, the BiOBr could oxidize its crystal Br− to generate Br2/HOBr efficiently, which is a more favorable process thermodynamically than oxidation of aqueous Br−. Furthermore, long-term stability (> 40 h) of BiOBr is maintained by adding KBr in the reaction system to automatically replenish Br− in BiOBr. This work provides a potential alternative to current industrial method for green synthesis of ethylene-derived commodity chemicals.

Solid-Binding Peptide-Guided Spatially Directed Immobilization of Kinetically Matched Enzyme Cascades in Membrane Nanoreactors.

Biocatalysis is a useful strategy for sustainable green synthesis of fine chemicals due to its high catalytic rate, reaction specificity, and operation under ambient conditions. Addressable immobilization of enzymes onto solid supports for one-pot multistep biocatalysis, however, remains a major challenge. In natural pathways, enzymes are spatially coupled to prevent side reactions, eradicate inhibitory products, and channel metabolites sequentially from one enzyme to another. Construction of a modular immobilization platform enabling spatially directed assembly of multiple biocatalysts would, therefore, not only allow the development of high-efficiency bioreactors but also provide novel synthetic routes for chemical synthesis. In this study, we developed a modular cascade flow reactor using a generalizable solid-binding peptide-directed immobilization strategy that allows selective immobilization of fusion enzymes on anodic aluminum oxide (AAO) monoliths with high positional precision. Here, the lactate dehydrogenase and formate dehydrogenase enzymes were fused with substrate-specific peptides to facilitate their self-immobilization through the membrane channels in cascade geometry. Using this cascade model, two-step biocatalytic production of l-lactate is demonstrated with concomitant regeneration of soluble nicotinamide adenine dinucleotide (NADH). Both fusion enzymes retained their catalytic activity upon immobilization, suggesting their optimal display on the support surface. The 85% cascading reaction efficiency was achieved at a flow rate that kinetically matches the residence time of the slowest enzyme. In addition, 84% of initial catalytic activity was preserved after 10 days of continuous operation at room temperature. The peptide-directed modular approach described herein is a highly effective strategy to control surface orientation, spatial localization, and loading of multiple enzymes on solid supports. The implications of this work provide insight for the single-step construction of high-power cascadic devices by enabling co-expression, purification, and immobilization of a variety of engineered fusion enzymes on patterned surfaces.

Green Synthesis of Zinc oxide Nanocomposite Using Fusarium oxysporum and Evaluation of the Anticancer Effect on Hepatocellular Carcinoma

Nanoparticles can be synthesized by chemical, physical and biological system methods. In this work, Superparamagnetic Iron Oxide@Silver nanoparticles (SPION@Ag NPs) were modified by zinc oxide nanoparticles (ZnO NPs). SPION@Ag core shell NPs were synthesized by the biological method using Fusarium oxysporum fungus and coated with ZnO NPs. This method is eco-friendly and low cost. Characterization techniques such as UV, FTIR, HR-TEM, HR-SEM, XRD and zeta potential were used. The most common type of liver cancer is hepatocellular carcinoma (HCC). Hepatocellular carcinoma was induced by a single dose of diethyl nitrosamine (DEN) 60 mg/Kg b.wt. and was followed after two days with carbon tetra chloride (CCl4) diluted with paraffin oil (50% v/v, 2 ml/Kg b.wt.) twice a week for one month. A histopathology examination was done after scarifying. Clear changes were shown in the comparison between the HCC group treated with ZnO@SPION@Ag nanocomposite and the positive control group. Liver function tests showed a highly significant decrease after using the nanocomposite for HCC treatment. Our study aim is to evaluate the therapeutic anticancer effect of ZnO@SPION@Ag nanocomposite on hepatocellular carcinoma in male albino rats, which was synthesized by a new method called green chemistry or green synthesis.

Obtaining Nanostructured ZnO onto Si Coatings for Optoelectronic Applications via Eco-Friendly Chemical Preparation Routes.

Although the research on zinc oxide (ZnO) has a very long history and its applications are almost countless as the publications on this subject are extensive, this semiconductor is still full of resources and continues to offer very interesting results worth publishing or warrants further investigation. The recent years are marked by the development of novel green chemical synthesis routes for semiconductor fabrication in order to reduce the environmental impacts associated with synthesis on one hand and to inhibit/suppress the toxicity and hazards at the end of their lifecycle on the other hand. In this context, this study focused on the development of various kinds of nanostructured ZnO onto Si substrates via chemical route synthesis using both classic solvents and some usual non-toxic beverages to substitute the expensive high purity reagents acquired from specialized providers. To our knowledge, this represents the first systematic study involving common beverages as reagents in order to obtain ZnO coatings onto Si for optoelectronic applications by the Aqueous Chemical Growth (ACG) technique. Moreover, the present study offers comparative information on obtaining nanostructured ZnO coatings with a large variety of bulk and surface morphologies consisting of crystalline nanostructures. It was revealed from X-ray diffraction analysis via Williamson–Hall plots that the resulting wurtzite ZnO has a large crystallite size and small lattice strain. These morphological features resulted in good optical properties, as proved by photoluminescence (PL) measurements even at room temperature (295 K). Good optical properties could be ascribed to complex surface structuring and large surface-to-volume ratios.

Recent advance in selective hydrogenation reaction catalyzed by biomass-derived non-noble metal nanocomposites

The green and sustainable synthesis of fine chemicals and pharmaceuticals urgently demands a new generation of efficient and robust catalysts in diverse organic transformations. Owing to their unique features of ready availability, natural abundance and renewability, environmental friendliness, and low-cost, the development of catalytically active materials derived from biomass has attracted extensive attention in the field of organic synthesis over the past few years. In this review, we summarize major progress in design and preparation of efficient and robust non-noble metal catalysts derived from various biomass feedstocks for green and sustainable selective hydrogenation transformations, with a particular focus on catalytic hydrogenation of nitro compounds, unsaturated CC bonds, quinoline compounds, CO bonds and so on. Finally, the challenges remaining in this research area are discussed and feasible future research directions are proposed.

Convenient and Reusable Manganese‐Based Nanocatalyst for Amination of Alcohols

AbstractThe development of new sustainable nanocatalytic systems for green chemical synthesis is a growing area in chemical science. Herein, a reusable heterogeneous N‐doped graphene‐based manganese nanocatalyst (Mn@NrGO) for selective N‐alkylation of amines with alcohols is described. Mechanistic studies illustrate that the catalytic reaction follows a domino dehydrogenation‐condensation‐hydrogenation sequence of alcohols and amines with the formation of water as the sole by‐product. The scope of the reaction is extended to the synthesis of pharmaceutically important N‐alkylated amine intermediates. The heterogeneous nature of the catalyst made it easy to separate for long‐term performance, and the recycling study revealed that the catalyst was robust and retained its activity after several recycling experiments.

Green synthesis and kinetic study of eco-friendly chelating agent by hydrothermal process for remediation of heavy metals

ABSTRACT Water management forms a critical issue in the world because water accessibility increments due to the lack of freshwater assets and contamination effects. Water contamination brought about by toxic elements is one of the most significant natural issues in the world. Heavy metals are poisonous to human and threatening for the surroundings. The goal of this study has been to examine the impacts of newly synthesised eco-friendly chelating agent on the removal of heavy metal ions from synthetic water. Here a new eco-friendly chelating agent based on the glycine and citric acid has been synthesised successfully in the high-pressure reactor without the use of any harmful chemicals, using only water as a solvent. Developed eco-friendly chelating agent, 2,2′-((2-(2-((carboxymethyl)amino)-2-oxoethyl)-2hydroxysuccinyl)bis(azanediyl)diacetic acid has been studied in the framework of green chemistry to address the issues of cleaner synthesis. In the perspective of green chemical synthesis and sustainable development, atom economy (AE), Environmental – Factor (E-Factor) and Process Mass Intensity has been estimated for the studied amide synthesis process. The effect of various parameters like pH of the solution, contact time, ratio of metal to chelate and temperature was examined for the removal of heavy metals like chromium, copper and zinc from synthetic water.

Novel Green Chemistry Synthesis of Nano-Hydroxyapatite using Soya Milk as a Natural Stabiliser

Present work describes a novel green chemistry synthesis of Nano – Hydroxyapatite (HAP) using Soya Milk (SM) as a Natural Stabiliser. The HAP is a biocompatible material and widely used in orthopaedic and dental applications. Nano-HAP powders are characterized using XRD, SEM, EDS and FTIR. These results show that the nano- HAP powders obtained by Green Chemistry Synthesis using Soya Milk (SM) as a Natural Stabiliser (NS) appear to be quite promising due to optimized pH and Ca/P ratio values that can be adapted for future research and development.

CO2 hydrogenation to methanol over partially embedded Cu within Zn-Al oxide and the effect of indium

Developing effective catalysts for CO2 hydrogenation to methanol is an important step to improve the efficiency of a promising process for green synthesis of fuels and chemicals. Optimizing the Cu dispersion is often the main goal in preparing Cu/ZnO-based catalysts due to the strong dependence of the catalytic activity on the Cu surface area. However, the catalytic properties are also related to the nature of the Cu-ZnO interface. Herein, a series of hydrotalcite-derived Cu/ZnO/Al2O3 catalysts were prepared for CO2 hydrogenation to methanol. The preparation method results in partially embedded Cu particles within the Zn-Al oxide matrix. This microstructure exhibits significantly enhanced intrinsic activity and methanol selectivity. Loss of the interfacial area between Cu and Zn-Al mixed oxide phase due to sintering of Zn-Al matrix is identified as the main reason for deactivation of the HT-derived catalysts. The influence of In on Cu/ZnO-based catalysts is also investigated. It is found that In decreases the activity but increases the methanol selectivity and stabilizes the Cu particles and the Zn-Al mixed oxide phase. The lower activity of the In-containing catalysts is linked to the inhibition of Cu active sites by CuxIny species.

Design of a Two-Week Organic Chemistry Course for High School Students: “Catalysis, Solar Energy, and Green Chemical Synthesis”

A two-week summer camp was designed, implemented, and then updated for high school students focusing on organic chemistry, solar energy, and green chemistry principles. Students learn about laboratory safety, perform organic reactions, go on field trips, and take part in interactive lessons that focus on both fundamental chemistry topics as well as green chemistry. Each lab experiment implements at least one green chemistry principle by reducing waste or reagent use while employing additional safety measures. The course has been edited and modified on the basis of student feedback to include additional lessons, field trips, a student presentation, and other activities. Responses to postcourse surveys provided feedback on each component and also indicated that student interest in STEM increased as students gained physical laboratory and research skills.

Enhancing Performance of Organic Electrosynthesis through Electrolyte Engineering and Mass Transport Control

Organic electrosynthesis has gained significant interest in pharmaceutical manufacturing over the past decade. This increased interest has been propelled by a proliferation of new green chemical synthesis methods that are highly selective, avoid the use of stoichiometric reducing or oxidizing agents, and reduce the need for downstream separations. Given this recent synthetic advances, reaction engineering approaches start to become important in order to achieve scalable chemical manufacturing processes that operate at high selectivity and high production rates. This presentation will discuss reaction engineering opportunities based on electrolyte design and transport control to enhance the performance of organic electrosynthesis processes. Specifically, I will present our work on understanding and improving the electrohydrodimerization of acrylonitrile (AN) for the production of adiponitrile (ADN) – a model electrochemical processes currently implemented at scale. Although this reaction is the largest and most successful organic electrosynthesis implemented in industry, it faces many challenges owing to its limited energy conversion and selectivity, which are common to reactions of interest in pharmaceutical manufacturing. I will first discuss the role of complex multi-ion electrolyte formulation on the selectivity of this reaction. [1, 2] Specifically, I will discuss the effects that supporting ions play in the electrical double layer (EDL) to control the reactivity of intermediates and direct electrochemical reactions towards desirable reaction pathways. We systematically explored the effects of the size of cations in the electrolyte and show that larger cations enhance selectivity towards ADN by modulating the reactivity of reactants and intermediates in the EDL. Furthermore, we show that intermediate pH regimes (between 7 and 11) are favorable for the production of ADN. Lower pH values enhance the hydrogen evolution reaction (HER) and the hydrogenation of AN, leading to the production of propionitrile (PN). Through the careful formulation of electrolytes, the concentration of reactants, operating current densities, and temperature, ADN selectivities as high as 83% can be achieved at intermediate current densities (- 26 mA cm-2). However, mass transport limitations have proven to be a challenge at high current densities, where the production of propionitrile (PN) dominates.In the second part of the presentation, I will provide experimental insights on how pulsed potential techniques can be used to mitigate mass transport limitations and effectively control the product distribution in ADN electrosynthesis.[3] Electrochemical pulses are used to balance AN diffusive flux to the electrode and its consumption in the electrical double layer (EDL), helping mitigate mass transport limitations at high current densities. This, together with their effect on the interaction between electroactive species and the reaction surface can help improve reaction selectivity. An improvement of over 250% in relative selectivity between ADN:PN was achieved optimizing pulse duration and amplitude, and a 20% increase in ADN production rate was achieved with respect to DC operation. The experimental data obtained for various pulse durations was then used to train machine learning algorithms which identified an optimal pulse sequence with a demonstrated 30% increase in ADN production with respect to DC operation. This new approach to electrosynthesis research which combines electrochemical design principles, judiciously designed experimental campaigns and machine learning can be used to uncover and optimize new electrosynthetic processes in pharmaceutical manufacturing.[1] Blanco, D. E., Dookhith, A. Z., & Modestino, M. A. (2019). Enhancing selectivity and efficiency in the electrochemical synthesis of adiponitrile. Reaction Chemistry & Engineering, 4(1), 8-16.[2] Blanco, D. E., Atwi, R., Sethuraman, S., Lasri, A., Morales, J., Rajput, N. N. and Modestino, M. A. Effect of Electrolyte Cations on Organic Electrosynthesis: The Case of Adiponitrile Electrochemical Production, Journal of The Electrochemical Society, 2020, 167, 155526.[3] Blanco, D. E., Lee, B., & Modestino, M. A. (2019). Optimizing organic electrosynthesis through controlled voltage dosing and artificial intelligence. Proceedings of the National Academy of Sciences, 116(36), 17683-17689.

Green chemical synthesis for well-defined and sharply distributed SiO2@FexOy particles

Using a non-toxic precursor, we created a green chemical synthesis for colloidal spheres with a core@shell structure having a silica core and an iron oxide shell (SiO2@FexOy). Our synthesis pathway enabled an iron oxide shell formation with a 9 ± 6 nm thick shell onto colloidal silica spheres (ca. 700 nm). SiO2@FexOy particles reduced A549 cell viability and induced DNA damage. SiO2@FexOy particles showed the potential for removing fluoride from water.

Metal-doped TiO2 nanocatalysts in an MX2/urea mixture for the synthesis of benzothiazoles bearing substituted pyrrolidin-2-ones: Enhanced catalytic performance and antibacterial activity

Solvents and catalysts are among the key factors in achieving the green chemical synthesis of bioactive compounds. In this regard, metal-doped nanoparticles, as a heterogeneous catalyst, in urea-based deep eutectic mixtures were used to prepare a series of pyrrolidinone-substituted benzothiazoles. In the strategy developed herein, pyrrolidinone derivatives were synthesized by reacting different arylamines with dimethyl itaconate using water as the solvent in a microwave. Then, the as-obtained pyrrolidinone derivatives were reacted with 2-aminothiophenol under microwave irradiation with the assistance of a deep eutectic mixture (CuCl2 or NiCl2/urea) and Cu- or Ni-doped TiO2 nanoparticles to afford the final derivative incorporating both pyrrolidin-2-one and benzothiazole rings. To determine the optimum reaction conditions, the effect of temperature, solvent nature, and reaction time was investigated. Under the optimal operation conditions, high reaction yields were achieved. The developed strategy exhibited advantages of a short reaction time, eco-friendliness, and high productivity. Finally, the obtained derivatives were examined in terms of their antibacterial potential against selected Gram-negative and Gram-positive bacterial strains: Eight of the derivatives exhibited activity against the tested bacteria.