Green Synthetic Methodology Research Articles

Structure-guided design and photochemical synthesis of new carbamo(dithioperoxo)thioates with improved potencies to SARS-CoV-2 3CLpro

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has triggered a protracted global pandemic from 2019 to 2022, and posed a significant threat to human health. One of the non-structural proteins 3CLpro of SARS-CoV-2 is considered as a validated target for the development of inhibitors against the virus. Disulfiram has been reported as a covalent inhibitor of 3CLpro; however, its structure lacks bonding site with active pockets of 3CLpro and its highly symmetric structure doesn’t match well with the irregular cavity of the active center, limiting its therapeutic applications. To enhance their affinity for the 3CLpro target, in this study, two kinds of disulfiram derivatives, designed based on the reevaluation and optimization of disulfiram, have been synthesized through photoredox chemistry, and the novel carbamo(dithioperoxo)thioates 4g-m were found to display 5–17 folds potency against SARS-CoV-2 3CLpro compared to the parent disulfiram, with resulting half-maximal inhibitory concentration (IC50) values ranging from 0.14–0.47 μM. Carbamo(dithioperoxo)thioates 4i containing a 4-hydroxy piperidine and a 4-trifluoromethyl phenyl ring, was identified as the most potent inhibitor to both 3CLpro (IC50 = 0.14 μM) and PLpro (IC50 = 0.04 μM). Furthermore, molecular dynamics simulations, binding free energy analysis and mass analysis were performed and provided insights on the stability, conformational behavior, and interactions of 4g with 3CLpro. The green synthetic methodology, the privileged carbamo(dithioperoxo)thioate scaffold, and the molecular mechanisms presented might serve as a useful system for the further discovery of highly potent inhibitors targeting SARS-CoV-2 3CLpro.

Biosynthesis of Ag‐CuO Nanocomposites: Efficient Catalyst for the Synthesis of Schiff Bases, Photodegradation of Congo Red Dye and Their Cytotoxicity Evaluation on MCF‐7 Cell Line

ABSTRACTAmid growing environmental concerns and the need for a sustainable future, green synthetic methodologies are gaining popularity for their simplicity and nontoxicity. In pursuit of the eco‐friendly synthesis of nanomaterials, the study reports an innovative synthesis of Ag‐CuO nanocomposites via the coprecipitation method utilizing Citrus limetta fruit juice extract as the bioreductant and stabilizing agent. The morphological and structural characteristics of the fabricated nanocomposites were evaluated by ultraviolet–visible diffuse reflectance spectroscopy (UV–vis DRS), Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy‐dispersive X‐ray (EDX), transmission electron microscopy (TEM), X‐ray diffraction (XRD), Raman and Brunauer–Emmett–Teller (BET) analyses. The nanocomposites were crystalline with particle sizes ranging from 15 to 24 nm and exhibited spherical and rod‐like shapes. The band gap value and specific surface area of the nanocomposites were found to be 1.5 eV and 25.50 m2/g, respectively. The photoluminescence (PL) analysis and electrochemical studies revealed significant charge separation and effective charge migration behaviour of the nanocomposites, respectively. The nanocomposites effectively catalysed the synthesis of Schiff bases from aryl aldehydes and aromatic amines at room temperature and without solvents. The reactions proceeded in a brief time with excellent product yields, and the nanocatalyst retained its activity for five consecutive cycles. The nanocomposites also efficiently catalysed the photodegradation of Congo red dye under visible light. A significant degradation of 94.33% was attained in 55 min, and the nanocatalyst maintained its efficacy over four consecutive reaction cycles. Moreover, the nanocomposites exhibited notable anticancer properties against the MCF‐7 (human breast) cell line, demonstrating a remarkable cytotoxicity rate of 87.79%. The findings highlight the efficacy of the biosynthesized nanocomposites in catalysis, environmental remediation and biological applications.

Green and Eco-friendly Synthetic Strategies for Quinoxaline Derivatives

Abstract: Advancement in green synthetic methodologies has brought a revolution in heterocyclic synthesis. Green synthesis has bypassed the classical procedures involving toxic/hazardous solvents or catalysts and improved the current environmental safety standards by many folds. Green chemistry research has continuously made significant contributions to the development of heterocyclic scaffolds both at laboratory and commercial scales. Researchers are continuously developing and exploring the principles of green chemistry for the development of novel therapeutic agents. Quinoxaline lies in the category of versatile heterocyclic motifs, which possesses a wide diversity in its derivatives as well as a broad profile of its therapeutic potential. In the past decades, many new green synthetic protocols have been developed and employed successfully for the synthesis of quinoxaline derivatives. These include the use of reusable nanocatalysts, polymers, various green solvents, tonsils, catalysts, water as a catalyst, microwave irradiation, ultrasonic waves, non-toxic metal catalysts, surfactants, etc. The present review focuses on various green synthetic procedures reported for quinoxalines along with the specializations and applications of the reactions.

Carbon quantum dots-based palladium complex: A versatile nano-catalyst for the green synthesis of pyrazoles

The palladium complex based on the magnetic carbon quantum dots [Fe3O4@CQDS@Si(CH2)3 NH@CC@ATT@Pd (CQDPd = F)] was synthesized by preparation of Fe3O4, its further reactions with carbon quantum dots (CQDs), (3-aminopropyl)triethoxysilane [Si(OEt)3(CH2)3NH2], cyanuric chloride (CC), and 3-amino-1,2,4-triazole-5-thiol (ATT), and complexation of the product with PdCl2. Then, it was characterized by several techniques such as FT-IR, XRD, EDX, SEM, TEM, VSM, and used as a novel catalyst for the green synthesis of diverse pyrazoles from the reaction of aldehydes, ethyl acetoacetate and phenylhydrazine at 70 °C under solvent-free conditions with high yields and short reaction times. Aldehydes bearing the electron-withdrawing groups exhibit the superior reactivity. Remarkably, the F catalyst showed strong recyclability over six consecutive cycles with negligible loss of activity, emphasizing its sustainability and high efficiency in chemical transformations as well as the catalytic potential of the used magnetic carbon quantum dots and their ability to revolutionize green and efficient synthetic methodologies.

Diamino-Substituted Quinones as Cathodes for Lithium-Ion Batteries.

This study introduces a sustainable approach to designing organic cathode materials (OCMs) for lithium-ion batteries as a potential replacement for traditional metal-based electrodes. Utilizing green synthetic methodologies, we synthesized and characterized five distinct quinone derivatives and investigated their electrochemical attributes within Li-ion battery architectures. Notably, the observed specific capacities were lower than the theoretical predictions, suggesting limitations in achieving efficient redox reactions in a coin-cell configuration. Among the quinone derivatives studied, one variant derived from natural vanillin showed superior cycle stability, maintaining 58% capacity retention over 95 charge-discharge cycles, and achieving a Coulombic efficiency of 90%. Importantly, we discovered that the commonly used Super-P conductive carbon did not yield any measurable battery performance; instead, these quinones necessitated the incorporation of graphene nanoplatelets as the conductive matrix. Through a facile one-step synthesis in ethanol or water, we have demonstrated a viable synthetic route for producing OCMs, albeit with moderate performances, which have attempted to address common concerns of high solubility and poor redox reactivity of previous OCMs, thereby offering a sustainable pathway for the development of organic-based energy storage devices.

Synthesis, toxicological and in silico evaluation of novel spiro pyrimidines against Culex pipiens L. referring to chitinase enzyme

The exponential development of resistance to conventional chemical insecticides adds another important motive for the creation of novel insecticidal active agents. One of the keys to meeting this challenge is the exploration of novel classes of insecticidal molecules with different modes of action. Herein, a novel series of spiro pyrimidine derivatives was prepared using some green synthetic methodologies such as microwave irradiation, and sonication under ultrasound waves. Spiro pyrimidine aminonitrile 1 is a key starting material for the synthesis of targets 2–9 by reaction with different carbon electrophiles and nitrogen nucleophiles. The structures of all the newly synthesized compounds were approved using spectral data. The toxicological efficiency and biological impacts of the synthesized spiro pyrimidine derivatives were assessed against Culex pipiens L. larvae. The toxicity of synthesized compounds showed remarkable variations against the C. pipiens larvae. Where, 3, 4 and 2 were the most efficient compounds with LC50 values of 12.43, 16.29 and 21.73 µg/mL, respectively. While 1 was the least potent compound with an LC50 value of 95.18 µg/mL. As well, other compounds were arranged according to LC50 values as follows 5 > 7 > 6 > 9 > 8. In addition, 3 and 4 exhibited significant prolongation of the developmental duration and greatly inhibited adult emergence. Moreover, many morphological deformities were observed in all developmental stages. Furthermore, cytotoxicity of the most effective compounds was assessed against the normal human cells (WI-38) as non-target organisms, where compounds 2, 4 and 3 showed weak to non-toxic effects. The study of binding affinity and correlation between chemical structure and reactivity was carried out using molecular docking study and DFT calculations to investigate their mode of action. This study shed light on promising compounds with larvicidal activity and biological impacts on the C. pipiens life cycle.

Light-assisted green and efficient construction of thiadiazole/selenadiazole derivatives

A green and efficient one-pot photocatalytic synthetic methodology was presented for fabrication of thiadiazole/selenadiazole derivatives with good group tolerance, safe conditions, and high yields.

Cu3(BTC)2 metal organic framework as a promising adsorbent for operative exclusion of toxic dyes and herbicide

Synthetic organic dyes and herbicide pollutants pose a significant threat to water quality due to their high solubility in water and widespread industrial discharge. In water conservation developments, the Metal-Organic Frameworks (MOFs) are considered confident and substantial for the exclusion of toxic organic dyes, due to their multi-potential assets of cost-effective, high pore volume, high thermal stability, easy adaptation to toxic dye molecules, and most of them are stable in water, etc. Hence, the green synthetic methodology was employed for the combination of Cu3(BTC)2 MOF, which is draped with carboxylate functionality ligands, as an adsorbent to remove the hazardous dyes of Methyl Orange (MO), Acid Yellow (AY), and toxic herbicide of Atrazine (ATZ) from contaminated wastewater. As-reported Cu3(BTC)2 was evidently characterized by XRD, FTIR, TGA, XPS, SEM, and EDAX analysis. The equilibrium adsorption capacity (Qe) value of as-reported Cu3(BTC)2 for AY, MO, and ATZ was better in comparison with the formerly reported adsorbent. The high adsorption capacity of Cu3(BTC)2 for AY (777 mg/g), MO (903 mg/g), and ATZ (484 mg/g) is principally explained by π-π and electrostatic interaction. As a result, Cu3(BTC)2 is reported and proposed as a suitable adsorbent for the abolition of toxic dyes and herbicides from contaminated water.

A versatile strategy to construct surface functionalized pH/redox dual stimuli‐responsive nanogels for targeted drug delivery

AbstractDeveloping facile, green, and efficient synthetic methodology for preparing surface‐functionalized nanogels has attracted tremendous attention in the field of polymer chemistry and biomaterials engineering. Herein, a series of “clickable” P(MAA‐PMA) nanogels with reactive alkyne groups were conveniently prepared by “one‐pot” reflux‐precipitation polymerization (RPP), their particle sizes and zeta potentials are solid content‐dependent. Using P(MAA‐PMA)‐1 nanogels as the model, the physicochemical properties including particle size, surface potential, morphology, solution stability, and pH/redox responsiveness were characterized in detail. Moreover, the pH/redox dual‐responsive drug release feature/kinetics and parameters were analyzed using Korsmeyer–Peppas model and Gallagher–Corrigan model. Then the surface of nanogels was facilely modified with various thiol‐containing functional ligands via thiol‐yne photo click reaction. As targeted drug carriers, doxorubicin (DOX)‐loaded folic acid (FA)‐functionalized nanogels (FA@Nanogels/DOX) demonstrated higher tumor cell proliferation inhibition effect in B16F10 cancer cells than that in CHO‐K1 normal cells, while the non‐FA‐functionalized counterparts (Nanogels/DOX) do not show similar effect. This work provides a versatile “one‐pot RPP‐photo Click functionalization” strategy to construct surface‐functionalized pH/redox dual responsive nanogels for efficient and targeted drug delivery.

Dual Tunability for Uncatalyzed N-Alkylation of Primary Amines Enabled by Plasma-Microdroplet Fusion.

The fusion of non-thermal plasma with charged microdroplets facilitates catalyst-free N-alkylation for a variety of primary amines, without halide salt biproduct generation. Significant reaction enhancement (up to >200×) is observed over microdroplet reactions generated from electrospray. This enhancement for the plasma-microdroplet system is attributed to the combined effects of energetic collisions and the presence of reactive oxygen species (ROS). The ROS (e.g., O2•-) act as a proton sink to increase abundance of free neutral amines in the charged microdroplet environment. The effect of ROS on N-alkylation is confirmed through three unique experiments: (i) utilization of radical scavenging reagent, (ii) characterization of internal energy distribution, and (iii) controls performed without plasma, which lacked reaction acceleration. Establishing plasma discharge in the wake of charged microdroplets as a green synthetic methodology overcomes two major challenges within conventional gas-phase plasma chemistry, including the lack of selectivity and product scale-up. Both limitations are overcome here, where dual tunability is achieved by controlling reagent concentration and residence time in the microdroplet environment, affording single or double N-alkylated products. Products are readily collected yielding milligram quantities in eight hours. These results showcase a novel synthetic strategy that represents a straightforward and sustainable C-N bond-forming process.

Dual Tunability for Uncatalyzed N‐Alkylation of Primary Amines Enabled by Plasma‐Microdroplet Fusion

AbstractThe fusion of non‐thermal plasma with charged microdroplets facilitates catalyst‐free N‐alkylation for a variety of primary amines, without halide salt biproduct generation. Significant reaction enhancement (up to >200×) is observed over microdroplet reactions generated from electrospray. This enhancement for the plasma‐microdroplet system is attributed to the combined effects of energetic collisions and the presence of reactive oxygen species (ROS). The ROS (e.g., O2⋅−) act as a proton sink to increase abundance of free neutral amines in the charged microdroplet environment. The effect of ROS on N‐alkylation is confirmed through three unique experiments: (i) utilization of radical scavenging reagent, (ii) characterization of internal energy distribution, and (iii) controls performed without plasma, which lacked reaction acceleration. Establishing plasma discharge in the wake of charged microdroplets as a green synthetic methodology overcomes two major challenges within conventional gas‐phase plasma chemistry, including the lack of selectivity and product scale‐up. Both limitations are overcome here, where dual tunability is achieved by controlling reagent concentration and residence time in the microdroplet environment, affording single or double N‐alkylated products. Products are readily collected yielding milligram quantities in eight hours. These results showcase a novel synthetic strategy that represents a straightforward and sustainable C−N bond‐forming process.

Recent Advancement in the Green Synthesis of Silver Nanoparticles

Abstract: Because of its miscellaneous properties, developing less environmentally hazardous and trustworthy methodologies has become one of the most crucial steps toward synthesizing nanoparticles (NPs) among researchers and scientists. In this direction, silver nanoparticles (AgNPs or SNPs) have gained much attention because of their anti-inflammatory, antibacterial, antiviral, and antifungal properties, potential toxicity, and unusual physicochemical features. Concerning the toxicity of silver nanoparticles, silver nanoparticles may prove to be an essential tool against many drugresistant microorganisms and substitutes for antibiotics. However, the synthesis of AgNPs using conventional methods had a toxic impact and caused much damage to the ecosystem. Researchers have used various production techniques to prevent the adverse effects of toxic chemicals, including algae, bacteria, fungi, and plants. This review study has covered recent advancements in green synthetic methodologies for synthesizing AgNPs. This insight provides a comprehensive overview of key findings in the green synthesis of Ag nanoparticles and attempts to focus on factors affecting their synthesis, characterization, applications, potential toxic impact on living organisms, merits/ demerits, and prospects.

Photoluminescence and Supercapacitive Properties of Carbon Dots Nanoparticles: A Review

Carbon Dots (CDs) have gained the attention of many researchers since its discovery in 2004 due to their unique nanostructure and properties. These are very promising carbonaceous nanomaterials having wide range of applications in sensors, imaging, energy storage, nanomedicine, electrocatalysis and optoelectronics. CDs have shown excellent physical and chemical properties like, high crystallization, good dispersibility and photoluminescence. Besides, these are now known to have excellent biocompatibility, long-term chemical stability, cost-effectiveness and negligible toxicity. Due to favourable physical structure and chemical characteristics, these nanocarbon-based materials have drawn an interest as supercapacitor (SC) electrode materials, opening upnew opportunities to increase the energy density and lifespan of SCs. Thus, variety of quick and affordable methods i.e., the arc-discharge method, microwave pyrolysis, hydrothermal method, and electrochemical synthesis have been developed to synthesize this versatile nanomaterial. There are undoubtedly many methods for creating CDs that are effective and affordable, but due to the safety and simplicity of synthesis, CDs made from waste or using environmentally friendly methods have been innovated. In order to devise sustainable chemical strategies for CDs, green synthetic methodologies based on "top-down" and "bottom-up" strategies have been prioritised. This review summarizes numerous synthetic strategies and studies that are essential for the creation of environment friendly processes for CDs. The recent developments in the use of CDs for photoluminescence and supercapacitance have been highlighted providing a clear understanding of the new source of energy and optoelectronic materials with a futuristic perspective.

Nano-Pd/Chitosan Composite: An Extremely Effective Catalyst to the Synthesis of Pyrazolyl Analogues through Suzuki–Miyaura Cross-Coupling Reactions in an Aqueous Medium

Substituted pyrazolyl derivatives were synthesized through Suzuki cross coupling of aromatic boronic acid with heterocyclic halide using newly synthesized nano-Pd/chitosan catalyst by the water-mediated green synthesis methodology. The reactivity of the nano-Pd catalyst was highly enhanced by incorporating palladium nanoparticles with a biopolymer chitosan matrix. The synthesized nano-Pd/chitosan catalyst was studied thoroughly for its structure, morphology, and other fundamental aspects such as the size and shape by various techniques including XRD, FESEM, and EDAX analyses. The scope of the catalyst was disclosed by their great stability with remarkable reusability for Suzuki cross-coupling reaction with twelve different boronic acids under the green synthetic methodology.

Synthesis of Catalyst Using Bio‐benign Precursors and Its Application in One‐Pot Catalytic Synthesis of Imidazo[1,2‐a]pyridines

AbstractDevelopment of catalysts using natural feedstock is the need of the current era, and accordingly, we have developed a new ligand N‐(2‐hydroxynapthylidene)‐L‐leucienyl‐4,6‐O‐ethylidene‐β‐D‐glucopyranosylamine using natural occurring D‐glucose and L‐amino acid. It interacts with several bio‐relevant metal ions like iron, copper, zinc, etc., but its association with cupric ions is immune to pH (4.2–9.1) change. In‐situ copper‐catalyzed reactions have been proven to be pivotal in many important organic syntheses, including imidazo[1,2‐a]pyridines, which is one of the important precursors of many drug molecules. Catalytic synthesis of imidazo[1,2‐a]pyridines requires high catalyst loading, hazardous solvent, high temperature, and long reaction time, which are major drawbacks towards green synthetic methodology. Interestingly, our glycoconjugate‐derived cupric complex catalyzes the reactions among aldehydes, 2‐aminopyridines, and terminal alkynes under the solvent‐free condition to afford one‐pot synthesis of imidazo[1,2‐a]pyridines and 23 derivatives have been reported in good to excellent yields (53–93 %) using lower reaction time, temperature, and catalyst loading compared to other reports on similar reactions. Hence, our approach enhances the green methodology towards the catalytic synthesis of imidazo[1,2‐a]pyridine derivatives.

Recent Developments on Synthesis of Organofluorine Compounds Using Green Approaches

Abstract: The synthesis of organofluorine compounds plays a vital role in the field of pharmaceuticals, agrochemicals, and materials since the fluorine-containing compounds have shown improved biological and physicochemical properties. Significant research has been directed towards synthesizing organofluorine compounds because organofluorine compounds have been displayed in several biological activities, including anticancer, antitumor, antihypertensive, antidepressant, anti-HIV and treatment of stroke. Due to several pharmaceutical applications of organofluorine compounds, numerous conventional as well as green synthetic methodologies have been developed for the synthesis of fluorine-containing compounds. However, particularly, the synthesis of organofluorine compounds using green approaches has been continuously attracting research interest since green approaches have several advantages, including the use of inexpensive and nontoxic reagents, catalytic, highly efficient, short reaction time, energy efficient, high reaction yields, and environmentally benign over the conventional methods. Among the green tools, the use of microwave-assisted synthesis, water, and ionic liquids as green solvent/reaction media, organocatalysts, photocatalysts, and solvent-free and catalyst-free reaction conditions have been exploited in the past decades for the synthesis of organofluorine compounds. In this review, we highlighted the recent developments in various green methods for the synthesis of organofluorine compounds via electrophilic fluorination for synthesis of various fluorohydrins, fluorinated acyclic & cyclic β -ketoesters, 1,3-dicarbonyl compounds, cyclic and acyclic ketones, α - cyanoesters, α-aryl-tetralones, α-amino acids, flavanones, and several fluorinated heterocycles such as fluorinated pyridine, pyrimidine, pyrrole, pyrazolone, benzofuran, indole, flavanone, and coumarin derivatives. In addition, some green methodologies have been highlighted for the synthesis of biologically active fluorinated compounds, including HIV-1 integrase inhibitors, 20-deoxy-20-fluorocamptothecin, fluorinated estrone, sclareolide, BMS- 204352 (MaxiPost), fluorinated naproxen and fluoxetine.

Novel synthetic methodology of Diclofenac derivatives and its spectrochemical studies

To design the novel synthetic scheme, structural modification, characterization, and pharmacological evaluation of new derivatives of Diclofenac drugs is the main aim of the current research work. We describe the utility of novel reagents and green synthetic methodology to formulate the derivatives to enhance its biological action without undesirable effects. Diclofenac sodium is the phenylacetic acid salt and categorized under nonsteroidal anti-inflammatory drug (NSAID) with pain-relieving, antipyretic, and anti-inflammatory activity, but it has limits and adverse effects as gastrointestinal irritation, small intestine damage, nausea, platelet dysfunction and vertigo. Diclofenac amide derivatives are prepared with Sulphanilic acid and Naphthylamine by the following methods such as reflux and microwave irradiation method. Structural modification is carried out to build up the desired properties. The new synthesized derivatives were structurally characterized with the help of FT-IR, UV–Visible spectroscopy, and MS spectrometry techniques. Further we propose the pharmacological evaluation of Diclofenac derivatives will be carried out by in-vivo and invitro methods.

A green and efficient synthetic methodology towards the synthesis of 1-allyl-6-chloro-4-oxo-1,4-dihydroquinoline-3-carboxamide derivatives.

Quinolone is a privileged scaffold in medicinal chemistry and 4-Quinolone-3-Carboxamides have been reported to harbor vast therapeutic potential. However, conversion of N-1 substituted 4-Quinolone 3-Carboxylate to its corresponding carbamates is highly restrictive. This motivated us to adopt a much simpler, scalable and efficient methodology for the synthesis of highly pure N-1 substituted 4- Quinolone-3-Carboxamides with excellent yields. Our adopted methodology not only provides a robust pathway for the convenient synthesis of N-1 substituted 4- Quinolone-3-Carboxamides which can then be explored for their therapeutic potential, this may also be adaptable for the derivatization of other such less reactive carboxylate species.

Low-crystalline Ni(OH)2 ultrathin nanosheets upcycled from solid wastes for efficient photoconversion of low-concentration CO2

Low-crystalline ultrathin nanosheets (UNSs) hold great potential for efficient photoreduction of anthropogenic CO2, while developing green synthetic methodologies and elucidating the structure-performance relationship remain significant challenges. Here, via a CaO-mediated strategy, we demonstrate a facile strategy for the large-scale production of low-crystalline Ni(OH)2 UNSs from industrial wastes. The resultant Ni(OH)2 UNSs deliver a superior CO formation rate of 9.2 μmol h−1 with a high selectivity of 93.1 % in low-concentration CO2 (10 %), which remarkably outperforms that of Ni(OH)2 NSs with high crystalline. Experimental and theoretical investigations demonstrate that the boosted performance originates from the fully exposed oxygen vacancies and low-coordination Ni sites, which facilitates the separation of photogenerated charge pairs and the adsorption and activation of diluted CO2. This work demonstrates a sustainable strategy for the large-scale synthesis of low-crystalline layered metal hydroxides, paving new avenues for the high-value utilization of industrial wastes in mitigating climate change.

Recent Developments in Nanocatalyzed Green Synthetic Protocols of Biologically Potent Diverse O-Heterocycles—A Review

The dynamic growth in green organic synthetic methodologies for diverse heterocyclic scaffolds has substantially contributed to the field of medicinal chemistry over the last few decades. The use of hybrid metal nanocatalysts (NCs) is one such benign strategy for ensuring the advancement of modern synthetic chemistry by adhering to the principles of green chemistry, which call for a sustainable catalytic system that converts reacting species into profitable chemicals at a faster rate and tends to reduce waste generation. The metal nanoparticles (NPs) enhance the exposed surface area of the catalytic active sites, thereby making it easier for reactants and metal NCs to have an effective interaction. Several review articles have been published on the preparation of metal NCs and their uses for various catalytic heterocyclic transformations. This review will summarize different metal NCs for the efficient green synthesis of various O-heterocycles. Furthermore, the review will provide a concise overview of the role of metal NCs in the synthesis of O-heterocycles and will be extremely useful to researchers working on developing novel green and simple synthetic pathways to various O-heterocyclic-derived molecules.