Eco-friendly Conditions Research Articles

Construction and characterization of Fe3O4@SiO2-Dop/Amide-BTA-pd(0) nanocomposite as a novel and efficient nanomagnetic recoverable catalyst for synthesis of 5-substituted 1h-tetrazoles in water

The development of efficient, and environmentally friendly catalytic systems for synthesis of 5-substituted 1H-tetrazoles is an important challenge in organic synthesis because tetrazole derivatives are well known in medicinal chemistry with many biological activities such as anti-bacterial, anti-fungal, anti-allergic, anti-viral, anti-cancer, reducing blood pressure, and so on. In this research, we fabricated a palladium(0) complex stabilized on magnetic Fe3O4 nanoparticles modified with dopamine and benzo[d]thiazole-2-carbonyl chloride [Fe3O4@SiO2-Dop/Amide-BTA-Pd(0)] (1) and evaluated its catalytic behavior in the synthesis of 5-substituted 1H-tetrazoles through one-pot tandem reactions of aryl halides with K4[Fe(CN)6] and sodium azide under eco-friendly conditions. One-pot tandem reactions of aryl halides with K4[Fe(CN)6] and sodium azide were conducted using a catalytic amount of 1 in the presence of potassium carbonate in water at 100 °C for 2 h the 5-substituted 1H-tetrazole products were obtained in high to excellent yields. At the end of the reaction, 1 can be easily recycled and the products obtained had high purity.

One-Pot Sustainable Synthesis of Highly Substituted Pyrimidines via Acceptorless Dehydrogenative Annulation of Alcohols Using Pincer Ni(II)-NNS Catalysts.

We report an efficient and sustainable synthesis of highly substituted pyrimidines promoted by nickel(II)-NNS pincer-type complexes via acceptorless dehydrogenative annulations of readily available alcohols, malononitrile, and guanidine/benzamidine salt under eco-friendly conditions for the first time. Different sets of Ni(II) complexes (C1-C3) encapsulated in NNS pincer-type thiosemicarbazone ligands have been synthesized and authenticated by analytical and spectroscopic (Fourier transform infrared, nuclear magnetic resonance, and high-resolution mass spectrometry) techniques. The solid state three-dimensional structure of a representative complex (C2) has been determined with the aid of single crystal XRD analysis and confirms a square planar architecture around the nickel ion. Further, the well-defined Ni(II) complexes have been employed as efficient catalysts for the fabrication of a wide range of 4-aminopyrimidine-5-carbonitrile derivatives (33 examples) from readily available alcohols with suitable coupling partners such as malononitrile and guanidine/benzamidine under eco-friendly conditions. The current catalytic approach affords maximum yields up to 95% utilizing 3 mol % catalyst loading and water/hydrogen as the only byproduct. A feasible catalytic pathway has been proposed based on the different control experiment reactions, which clearly indicate that the coupling reaction proceeds via aldehyde and benzylidenemalononitrile intermediates. The practicability of the current protocol has been demonstrated by the large-scale synthesis of one of the products, 4-amino-2,6-diphenylpyrimidine-5-carbonitrile, and a short synthesis of a cytosine antifungal analogue.

New Twists in the Chemistry of Thioureas: 1,3-Thiazolidines as a Vector of Sustainability.

This study introduces a sustainable and pioneering cascade synthesis of 1,3-thiazolidine derivatives under eco-friendly conditions. The methodology transcends traditional approaches yielding complex novel compounds with unique N,S-heterocyclic structures. By operating at room temperature, utilizing green solvents, and minimizing excess of reactants, this procedure offers an innovative pathway for sustainable chemical development. Notably, this method not only prioritizes sustainability but also delivers high-purity products with exceptional yields. The simplicity of the process, requiring only a simple filtration and featuring short reaction times, underscores its efficiency and utility.

Development and validation of stability-indicating method of etrasimod by HPLC/DAD/MS/MS technique with greenness profiling

Etrasimod, a novel selective sphingosine-1-phosphate receptor modulator, was recently approved by the U.S. Food and Drug Administration and the European Medicinal Agency for the treatment of moderately to severely active ulcerative colitis in adults. In this research, the forced degradation study as an integral part of drug product and packaging development, which generates data on degradation mechanisms, is published. The development and validation of the stability-indicating method using a superior high-performance liquid chromatography technique coupled with a diode array detector and tandem mass spectrometer was performed to support the forced degradation study and monitor the formation of degradation products. Etrasimod demonstrated good stability under elevated temperature and basic stress conditions, while acidic hydrolysis, oxidative, and photolytic degradation produced eight degradation products. The knowledge of degradation products will be useful in the long-term stability study for establishing the acceptance criteria of etrasimod as a drug substance and dosage form during quality control and stability assessment. The eco-friendliness of the developed forced degradation procedure was evaluated using various greenness appraisal tools. The green metric tools showed that the forced degradation procedure obeys eco-friendly conditions.

Photoinduced Catalyst-Free Deuterodefunctionalization of Aryltriazenes with CDCl3.

A photoinduced deuterodetriazenation of aryltriazenes with CDCl3 under catalyst-free conditions is reported. The reactions featured simple operation, ecofriendly conditions, readily available reagents, inexpensive D sources, precise site selectivity, and a wide range of substrates. Since aryltriazenes could be readily synthesized from arylamine, this protocol can be used as a general method for easily and accurately incorporating deuterium into aromatic systems by using CDCl3 as a D source.

SOCIAL AND ENVIRONMENTAL ANALYSIS CONTRIBUTIONS TO FLORICULTURE IN THE HYDRANGEA SECTOR THROUGH A LIFE CYCLE ASSESSMENT APPROACH

In La Paz Province (Eastern Antioquia, Colombia), hydrangea floriculture has emerged as a significant driver of economic and social development following the post-conflict situation, offering high value-added contributions to the territory. The objective was to identify both the social and environmental aspects of hydrangea cultivation by small and medium-sized growers, assessing the environmental impacts and externalities across the crop’s life cycle. This initiative aimed to foster sustainable growth in floriculture production under eco-friendly conditions, safeguarding human health, and benefiting local stakeholders. To establish a methodological framework, the study adhered to the requirements and guidelines outlined in ISO 14040 and 14044 standards for environmental life cycle assessment, in addition to utilizing the UNEP Methodological Guide. The research revealed significant findings, highlighting the key environmental impacts affecting hydrangea production throughout its life cycle. These impacts primarily stem from the excessive use of agrochemicals, which pose risks to human health and ecosystems due to alterations in soil properties. Moreover, the reliance on fossil resources (such as plastics and fuels) at various stages of the cultivation process contributes to these impacts. From a social perspective, the study identified stakeholders and critical aspects requiring improvement, including integration, safety, occupational health, proper agrochemical handling, regulatory compliance, and system replacement issues. These challenges underscore the complexity of achieving sustainability, emphasizing the need for specialized technical support and new knowledge for growers. Implementing cost-effective technologies is crucial to mitigate environmental impacts, along with fostering associativity models among hydrangea crop producers, which significantly contribute to enhancing growing conditions.

One–Pot Three–Component Synthesis of 2,4,5–Triaryl Imidazoles using Fe3O4@BisImid−CuBr Nanocomposite as an Ecofriendly and Efficient Magnetically Reusable Catalyst

AbstractImidazoles are one of the keys of N‐heterocycle molecules that exist in the structure of many biomolecules. In this research project, we reported that Fe3O4@BisImid−CuBr nanocomposite is an attractive and efficient nanomagnetic catalyst to afford 2,4,5–triaryl imidazoles through reactions of 1,2–diketones and aldehydes in the presence of NH4OAc under ecofriendly conditions. The Fe3O4@BisImid−CuBr nanocomposite was readily fabricated by a simple method from available reagents and its structure was analyzed by spectroscopic techniques. SEM and TEM images affirmed the formation of particles in spherical shape and nanometer–size. Under this methodology, a diverse library of triaryl imidazoles were afforded with high yields in water. This synthetic methodology has significant features such as (a) high yields and high purity of the products (b) suitable reaction time (c) use of magnetic reusable nanocatalyst (d) high reusability of Fe3O4@BisImid−CuBr nanocatalyst and the performance of reactions in aqueous medium.

Ultrasound-assisted nano-GO/NiO mediated green synthesis, DFT studies and antiinflammatory activity of spiro indoles

An improved procedure has been developed for synthesizing derivatives of spiroindole in 84–87% yield by using catalytic amount of graphene oxide supported nickel oxide nanocomposite (GO/NiO NC) as a proficient heterogeneous catalyst under ultrasonic-irradiation. GO/NiO NC can be recycled and reused for three successive runs with slight reduction in its catalytic activity. Short reaction time, simple workup, and eco-friendly conditions are key features of the current protocol. Most importantly, the synthesized compounds, 4b, 4c, 5b, 5c, and 5d showed good anti-inflammatory potential by inhibiting protein denaturation at all the given concentrations. HOMO-LUMO studies indicate that the carbonitrile derivatives have the smallest energy gap which implies more chemical reactivity.

Honey-assisted synthesis and properties of silver nanoparticles in aqueous solution and inside supramolecular aggregates. The Cassyopea® effect

In this work we introduce supramolecular aggregates named Cassyopea®, acronym of combined and sustainable synthesis of payload-enriched aggregates from the method used for their preparation. Herein, Cassyopea® were described as reactors and carriers for silver nanoparticles (AgNPs) obtained from honey according to eco-friendly conditions. Spherical, monodisperse, and negatively charged NewAgNPs®, acronym of natural ecosustainable way AgNPs, having a mean size of 30 nm and high stability over time were prepared in aqueous solution. The successful synthesis of NewAgNPs® inside Cassyopea® was demonstrated by UV–vis spectroscopy, emission scanning electron microscopy (FE-SEM) and energy-dispersive X-ray (EDX) analysis. The protective effect of Cassyopea® on NewAgNPs® against the oxidation induced by H2O2 was kinetically determined in the Fenton-like reaction suggesting that the investigated nanoparticles tend to be located in the aqueous core of the investigated aggregates. Furthermore, microbiological assays revealed the tendency of Cassyopea® to preserve the biological activity of NewAgNPs® against Gram-positive and Gram-negative bacteria. The preparation of silver nanoparticles directly into supramolecular aggregates instead of their loading in preformed state is unprecedented, and the data reported for NewAgNPs® and Cassyopea® highlight promising applications in nanotechnology.

An improved immobilized molybdenum oxidative catalyst bearing an amino acid-derived bifunctional chelator

Herein we introduce a new glycine-bisphenol molybdenum(VI) complex, SBA@AP-GDC-Mo, immobilized on ordered mesoporous silica SBA-15 (Santa Barbara Amorphous) as an efficient and selective heterogenous catalyst. SBA@AP-GDC-Mo was fully characterized by Fourier transform-infra red (FT-IR), thermogravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), field emission-transmission electron microscopy (FE-TEM), inductively coupled plasma-optical emission spectroscopy (ICP-OES) and Barrett–Joyner–Halenda (BJH) and Brunauer–Emmett–Teller (BET) adsorption isotherms. The catalytic performance of SBA@AP-GDC-Mo was evaluated in the chemoselective oxidation of sulfides to sulfoxides and sulfones and found to be superior to our previously reported diamine–bisphenol molybdenum(VI) catalyst. The advantages of SBA@AP-GDC-Mo include high activity and better chemoselectivity under mild and eco-friendly conditions (e.g., ambient temperature using aqueous or aqueous–ethanolic solutions), recyclable for at least four cycles and easier overall synthesis in good yields including tethering of the ligand to the support.

Decontamination of Cobalt-Polluted Soils Using an Enhanced Electro-kinetic Method, Employing Eco-friendly Conditions

Decontamination of Cobalt-Polluted Soils Using an Enhanced Electro-kinetic Method, Employing Eco-friendly Conditions

Copper (II) complex supported on magnetic nanoparticles as a novel nanocatalyst for the synthesis of imidazo[1,2-a]pyridines.

Research on the synthesis of imidazo[1,2-a]pyridines has gained great importance among synthetic chemists because there have been numerous reports of their biological and medicinal activities. In this respect, we fabricated CuCl2 immobilized on Fe3O4 nanoparticles modified with 1,10-phenanthroline-5,6-diol [Fe3O4@Diol/Phen-CuCl2] and investigated its catalytic activity for the preparation of imidazo[1,2-a]pyridine derivatives through one-pot three-component reaction of 2-aminopyridines, aldehydes and terminal alkynes under ecofriendly conditions. FT-IR spectroscopy, EDX, SEM, TEM, XRD, TGA, VSM and ICP-OES techniques employed in order to identify the structure of the as-constructed Fe3O4@Diol/Phen-CuCl2 nanocatalyst. This catalytic system has a series of advantages such as the synthesis of imidazo[1,2-a]pyridine products with high yields in suitable time, performing the reactions in an environmentally friendly solvent (PEG), easy preparation of the catalyst with a simple method, and the recyclability of the Fe3O4@Diol/Phen-CuCl2 nanocatalyst.

Construction and characterization of a magnetic nanoparticle-supported Cu complex: a stable and active nanocatalyst for synthesis of heteroaryl-aryl and di-heteroaryl sulfides.

Diaryl and di-heteroaryl sulfides exist in the structure of many drugs and important biological compounds, also these compounds are well-known in medicinal chemistry due to important biological and pharmaceutical activities. Therefore, the development of novel, ecofriendly and efficient catalytic systems for the preparation of diaryl and di-heteroaryl sulfides is a very attractive and important challenge in organic synthesis. In this attractive methodology, we wish to introduce Fe3O4-supported 3-amino-4-mercaptobenzoic acid copper complex (Fe3O4@AMBA-CuI) nanomaterials as a novel and efficient magnetically recoverable catalyst for the preparation of heteroaryl-aryl and di-heteroaryl sulfides with high yields through reaction of heteroaryl halides with aryl or heteroaryl boronic acids and S8 as the sulfur source under ecofriendly conditions. This catalytic system was very efficient and practical for a diverse range of heteroaryl substrates including benzothiazole, benzoxazole, benzimidazole, oxadiazole, benzofuran, and imidazo[1,2-a]pyridine, because the desired diaryl and di-heteroaryl sulfides were prepared with high yields. The reusability-experiments revealed that the Fe3O4@AMBA-CuI nanocatalyst can be magnetically separated and reused at least six times without a significant decrease in its catalytic activity. VSM and ICP-OES analyses confirmed that despite using the Fe3O4@AMBA-CuI nanocatalyst 6 times, the magnetic properties and stability of the catalyst were still maintained. Although all the obtained heteroaryl-aryl and di-heteroaryl sulfide products are known and previously reported, the synthesis of this number of heteroaryl-aryl and di-heteroaryl sulfides has never been reported by any previouse methods.

Box–Behnken design for the optimisation of Kabachnik–Fields reaction catalysed by natural kaolinite clay under eco-friendly conditions

Kaolin catalysed the Kabachnik–Fields reaction. Box–Behnken design optimisation. Green chemistry conditions.

Electrochemical semi-hydrogenation of adiponitrile over copper nanowires as a key step for the green synthesis of nylon-6.

The industrial production of nylon 6 usually includes synthesizing caprolactam through the cyclohexanone-hydroxylamine route. This approach requires complex protocols, elevated temperatures, noble metal catalysts and the use of hazardous strong acids or hydroxylamine. Additionally, a significant quantity of ammonium sulphate is generated during the synthesis procedure. This study aims to develop an electrochemical reduction system for the conversion of ADN generated from the electrolytic dimerization of acrylonitrile (AN) to 6-aminocapronitrile (ACN), a precursor of nylon 6. This system utilizes a cost-effective Cu nanomaterial under eco-friendly conditions, avoiding lengthy and harsh processes, eliminating NH2OH use, and reducing low-value ammonium sulfate generation. This electrosynthesis method maintains approximately 85% ACN selectivity at 40-100 mA cm-2 when passing the charge required for 37% theoretical conversion. When extending the reaction time to achieve an 80% conversion, ACN selectivity still reached 81.6%, exceeding the theoretical value of non-selective hydrogenation by 20%. The pseudo-first-order reaction kinetic modeling proves that the reaction rate constant for ADN hydrogenation is significantly greater than that for ACN hydrogenation, highlighting the selectivity advantage of the system for ACN. This study establishes the foundation for developing a continuous electrolysis process to produce the nylon 6 precursor from AN feedstock.

Exploring enantiopure zinc-scorpionates as catalysts for the preparation of polylactides, cyclic carbonates, and polycarbonates.

New and simple ligand design strategies for the preparation of versatile metal-based catalysts capable of operating under greener and eco-friendly conditions in several industrially attractive processes are in high demand for society development. We present the first nucleophilic addition of an organolithium to ketenimines which incorporates a stereogenic centre in an N-donor atom to prepare new enantiopure NNN-donor scorpionates. We have also verified its potential utility as a valuable scaffold for chirality induction through the preparation of inexpensive, non-toxic and asymmetric zinc complexes. The pro-ligands and the corresponding zinc-based complexes have been characterized by X-ray diffraction studies. DFT studies were carried out to rationalize the different complexation abilities of these pro-ligands. These complexes have proved to act as highly efficient catalysts for a variety of sustainable bioresourced processes that are industrially attractive, with a wide substrate scope. Thus, complex 7 behaves as a highly efficient initiator for the well-behaved living ring-opening polymerization (ROP) of rac-lactide under very mild conditions. The PLA materials produced exhibited enhanced levels of isoselectivity, comparable to the highest value reported so far for zinc-based catalysts (Pi = 0.88). In addition, the combination of 7 with onium halide salts functioned as a very active and selective catalyst for CO2 fixation into five-membered cyclic carbonates through the cycloaddition of CO2 into epoxides under very mild and solvent-free conditions, reaching very good to excellent conversions (TOF = 227 h-1). Furthermore, this bicomponent system exhibits a broad substrate scope and functional group tolerance, including mono- and di-substituted epoxides, as well as the very challenging bio-renewable tri-substituted terpene-derived cis/trans-limonene oxide, whose reaction proceeds with high stereoselectivity. Finally, complex 7 also achieved high activity and selectivity as a one-component initiator for the synthesis of poly(cyclohexene carbonate)s via ring-opening copolymerization (ROCOP) of cyclohexene oxide and CO2 under very soft conditions, affording materials with narrow dispersity values.

Size exclusion chromatography as green support for forced degradation study of adalimumab.

Size exclusion chromatography (SEC) has become a powerful tool for analysing size variants of biologic drugs in their native form. Modern SEC can be defined by the use of chromatographic columns packed with sub-3 µm particles, allowing an increase in method throughput compared to that of conventional SEC. We performed the forced degradation study of adalimumab, the first genetically engineered fully humanised immunoglobulin G1 monoclonal antibody, and evaluated tha possibilities of an advanced SEC column packed with sub-3 µm particles for elucidation of the degradation pathway. Our results revealed the main adalimumab degradation products to be antibody fragments. Acidic and basic conditions had the most intensive effect on the degradation of the adalimumab while the drug exhibits relative stability under thermal and photolytic stress conditions. The AGREE and AGREEprep calculators were used for the evaluation of the environmental performance of the forced degradation procedure. The results of the green score evaluation are presented as round pictograms with a circle in the centre that shows the overall score of 0.81 and 0.61, respectively. Both pictograms are highlighted in green, indicating the eco-friendly conditions.

Blue-light-triggered C[sbnd]C bond formation for synthesis of functional malononitrile using CBr4 as photocatalyst

Compounds with cyclic structures derived from malononitrile are crucial in the field of pharmaceutics. Herein, we developed a facile synthetic protocol to give functional malononitrile derivatives via light-triggered alkylation using CBr4 as a photocatalyst under mild and eco-friendly conditions. A rich array of ethylene malononitriles, together with tetrahydrofuran were used as substrates, and metal-free coupling reaction occurred by forming new CC bonds. This reaction showed a wide range of scopes with tolerance of various functional groups with reasonable yields. Mechanism studies with the assistance of DFT calculations indicated such a reaction undertaking a radical pathway. We expected this protocol to be a useful platform for metal-free CC coupling reactions.

Eco-Friendly Homo- and Cross-Etherification of Benzyl Alcohols Catalyzed by Iron(II/III) Chloride in Propylene Carbonate as a Green and Recyclable Solvent.

A new catalytic approach toward the symmetrical and nonsymmetrical etherification of benzyl alcohols was developed. The symmetrical etherification reaction was carried out in the presence of FeCl3·6H2O (5 mol %) as the catalyst and propylene carbonate as a green and recyclable solvent and led to the corresponding symmetrical ethers in 53 to 91% yields. The nonsymmetrical etherification of benzylic alcohols was achieved by using FeCl2·4H2O (10 mol %) in the presence of a pyridine bis-thiazoline ligand (12 mol %) and allowed for high selectivity and in 52 to 89% yields. These methods take advantage of eco-friendly conditions.

GC–MS determination of 7-dehydrocholesterol and cholesterol in milk to verify eco-friendly conditions in cow housing

Dairy products are consumed worldwide in large quantities and play an important role in a diet. Labelling of these products as “eco”, “bio” or “organic” has become a trend in recent years, and verification of such advertised properties directly from the dairy products themselves, without the possibility of examining the environment where they were produced, is often next to impossible. However, it is crucial for combating potential false advertising. Herein, a simple approach to distinguish between indoor and outdoor rearing based on quantitation of cholesterol and 7-dehydrocholesterol in milk samples by GC–MS was evaluated. Repeated liquid–liquid extraction into n-heptane resulted in 99% extraction yield. Quantitation by internal standard calibration method with epicoprostanol provided limits of quantitation of 0.814 µg/100 g and 5.60 µg/100 g in milk for cholesterol and 7-dehydrocholesterol, respectively. Values of parameter defined as thousandfold 7-dehydrocholesterol to cholesterol ratio ranged from 0.35 to 1.34 for outdoor reared cows in comparison with indoor category (2.14 to 2.85). A statistically significant difference (at 99% confidence level) between indoor and outdoor rearing was observed. The developed method is an efficient tool for verification of livestock living conditions and, hence, for verification of eco-friendly labelling by dairy producers.