Derivatives In Aqueous Media Research Articles

Heteroarylation of Organophosphonium Salts with Indoles in Water: Synthesis of Symmetrical and Unsymmetrical 3,3′‐Bisindolylmethane Derivatives.

AbstractA method for the synthesis of symmetrical and unsymmetrical 3,3′‐bis(indolyl)methanes (3,3′‐BIMs) has been developed through the direct heteroarylation of indolyl‐containing di(hetero)aryl phosphonium salts with indole derivatives in aqueous media. This metal‐free reaction proceeds smoothly under mild conditions, eliminating the need for hazardous solvents and expensive additives/catalysts typically used in conventional synthesis routes, thereby highlighting the synthetic practicality and efficiency of the process. The success of this approach is largely attributed to the role of water as a promoter, facilitating the C−P bond functionalization of the phosphonium salts. Furthermore, the reaction demonstrates a broad substrate scope, good functional group tolerance, and excellent scalability. Moreover, the protocol can also be extended to the synthesis of triindolylmethane compound and diarylmethylated indole.

Sulfamic Acid Catalyzed One‐Pot Three‐Component Synthesis of Spiro‐Oxindole Fused Dihydroquinazolinone Derivatives in Aqueous Medium

AbstractA simple, efficient, and straightforward protocol has been developed for the synthesis of spiro‐oxindole fused dihydroquinazolinone derivatives from one‐pot three‐component reactions of isatoic anhydride, various primary anilines, and substituted isatins using a catalytic amount of sulfamic acid as an organocatalyst in water under refluxed conditions. All the synthesized compounds were formed within just 2 h and isolated pure by simple filtration with excellent yields (89%–94%). Gram scale production, use of commercially available low‐cost organocatalyst, green solvent, reusability of the medium, one‐pot three‐component reaction strategy, no column chromatography, and high atom economy are some of the major benefits of this newly developed protocol.

Long Stability of Atomically Precise Red Emissive Copper Nanoclusters within the Gel and Their Use As a Potential Catalyst and Fluorescent Ink.

Herein, an amphiphile-based hydrogel (with 5% DMF) containing natural amino acid residue has been used to prepare and stabilize red-emitting CuNCs for several months. Though different methods have been attempted, amphiphile and 4-mercaptobenzoic acid (4-MBA)-containing hydrogels are pinpointed to be the base medium to stabilize this new Cu-cluster. From a MALDI-TOF MS analysis it was found that it is a Cu8-atom cluster stabilized by three 4-MBA ligands. Copper acetate monohydrate (Cu(CH3COO)2·H2O) has been used as a copper precursor, and l-ascorbic acid has been used as a reducing agent. FEG-TEM analysis shows that the Cu cluster has an average size of 2.83 nm. Interestingly, these clusters can be used as a fluorescent ink with a visibility of the solid state under a UV-lamp with an excitation of 365 nm. This envisaged applying these CuNCs for anticounterfeiting. These Cu-clusters show an excitation of 420 nm with an emission of 620 nm, as is evident from the fluorescence spectroscopic analysis. Based on our knowledge, this is the first example of making and consequently stabilizing Cu-clusters using hydrogel as a template for a few months. Moreover, these CuNCs can also be used as a catalyst for the reduction of nitro derivatives to their amine derivatives in aqueous medium.

Development of new PDMS in tube extraction microdevice for enhanced monitoring of polycyclic aromatic hydrocarbons and their derivatives in water

Contamination by polycyclic aromatic hydrocarbons (PAHs) is an urgent environmental concern, given its atmospheric dispersion and deposition in water bodies and soils. These compounds and their nitrated and oxygenated derivatives, which can exhibit high toxicities, are prioritized in environmental analysis contexts. Amid the demand for precise analytical techniques, comprehensive two-dimensional chromatography coupled with mass spectrometry (GCxGC/Q-TOFMS) has emerged as a promising tool, especially in the face of challenges like co-elution. This study introduces an innovation in the pre-concentration and detection of PAHs using an extraction fiber based on polydimethylsiloxane (PDMS), offering greater robustness and versatility. The proposed technique, termed in-tube extraction, was developed and optimized to effectively retain PAHs and their derivatives in aqueous media, followed by GCxGC/Q-TOFMS determination. Fiber characterization, using techniques such as TG, DTG, FTIR, and SEM, confirmed the hydrophobic compounds retention properties of the PDMS. The determination method was validated, pointing to a significant advancement in the detection and analysis of PAHs in the environment, and proved effective even for traces of these compounds. The results showed that the detection limits (LOD) and quantification limits (LOQ) ranged from 0.07 ng L−1 to 1.50 ng L−1 and 0.33 ng L−1 to 6.65 ng L−1, respectively; recovery ranged between 72 % and 117 %; and the precision intraday and interday ranged from 1 % to 20 %. The fibers were calibrated in the laboratory, with exposure times for analysis in the equilibrium region ranging from 3 to 10 days. The partition coefficients between PDMS and water were also evaluated, showing logarithm values ranging from 2.78 to 5.98. The fibers were applied to the analysis of real water samples, demonstrating high capacity. Additionally, given the growing demand for sustainable methods, the approach presented here incorporates green chemistry principles, providing an efficient and eco-friendly solution to the current chemical analysis scenario.

Facile acid-mediated one-pot synthesis of dihydropyran and furan derivatives in aqueous media

An efficient and environmentally-friendly procedure is herein reported for the synthesis of dihydropyran and furan derivatives in aqueous media. This protocol is both facile and chemo-selective, without the use of any metal catalyst. Notably, this reaction demonstrates broad substrate scope, high efficiency, and good tolerance towards functional groups.

Kinetic Assessment of the Catalytic Effect of Halide Ions on the Halogenations of Thiazole and Its Methyl Derivatives in Aqueous Medium

Kinetic Assessment of the Catalytic Effect of Halide Ions on the Halogenations of Thiazole and Its Methyl Derivatives in Aqueous Medium

Mechanisms Associated with Superoxide Radical Scavenging Reactions Involving Phenolic Compounds Deduced Based on the Correlation between Oxidation Peak Potentials and Second-Order Rate Constants Determined Using Flow-Injection Spin-Trapping EPR Methods.

Flow-injection spin-trapping electron paramagnetic resonance (FI-EPR) methods that involve the use of 5,5-dimethyl-pyrroline-N-oxide (DMPO) as a spin-trapping reagent have been developed for the kinetic study of the O2•- radical scavenging reactions occurring in the presence of various plant-derived and synthetic phenolic antioxidants (Aox), such as flavonoid, pyrogallol, catechol, hydroquinone, resorcinol, and phenol derivatives in aqueous media (pH 7.4 at 25 °C). The systematically estimated second-order rate constants (ks) of these phenolic compounds span a wide range (from 4.5 × 10 to 1.0 × 106 M-1 s-1). The semilogarithm plots presenting the relationship between ks values and oxidation peak potential (Ep) values of phenolic Aox are divided into three groups (A1, A2, and B). The ks-Ep plots of phenolic Aox bearing two or three OH moieties, such as pyrogallol, catechol, and hydroquinone derivatives, belonged to Groups A1 and A2. These molecules are potent O2•- radical scavengers with ks values above 3.8 × 104 (M-1 s-1). The ks-Ep plots of all phenol and resorcinol derivatives, and a few catechol and hydroquinone derivatives containing carboxyl groups adjacent to the OH groups, were categorized into the group poor scavengers (ks < 1.6 × 103 M-1 s-1). The ks values of each group correlated negatively with Ep values, supporting the hypothesis that the O2•- radical scavenging reaction proceeds via one-electron and two-proton processes. The processes were accompanied by the production of hydrogen peroxide at pH 7.4. Furthermore, the correlation between the plots of ks and the OH proton dissociation constant (pKa•) of the intermediate aroxyl radicals (ks-pKa• plots) revealed that the second proton transfer process could potentially be the rate-determining step of the O2•- radical scavenging reaction of phenolic compounds. The ks-Ep plots provide practical information to predict the O2•- radical scavenging activity of plant-derived phenolic compounds based on those molecular structures.

Synthesis of 1H-isoindolin-1-ones via a simple photodecarboxylative addition of carboxylates to phthalimides and evaluation of their antibiotic activity

A variety of 3-hydroxy-isoindolin-1-one derivatives were synthesized using the photodecarboxylative addition of carboxylates to phthalimide derivatives in aqueous media. Subsequent acid-catalyzed dehydration furnished 3-(alkyl and aryl)methyleneisoindolin-1-ones with variable E-diastereoselectivity in good to excellent overall yields. Noteworthy, the parent 3-phenylmethyleneisoindolin-1-one underwent isomerization and oxidative decomposition when exposed to light and air. Selected 3-hydroxy-isoindolin-1-one and 3-(alkyl and aryl)methyleneisoindolin-1-one derivatives showed moderate antibacterial activity that justifies future elaboration and study of these important bioactive scaffolds.Graphical abstract

Fe (III)–porphyrin complex as an efficient and recyclable homogeneous catalyst for the synthesis of pyrano thiazole 6-carbonitrile derivatives in aqueous medium

In this study, the Fe(III)–porphyrin complex (FePOphy complex) was successfully utilized as an efficient and recyclable catalyst for a one-pot, three-component reaction involving aromatic aldehydes, 2,4-thiazolidenedione, and malononitrile. This reaction led to the synthesis of pyrano thiazole 6-carbonitrile derivatives under environmentally friendly conditions. The structures of the formed compounds were determined through elemental and spectral analyses including infrared (IR, 1H NMR and 13C NMR, CHN and mass spectrometry, confirming the successful synthesis of the desired products. The reactions were conducted in a compassionate environment using a green solvent (H2O/EtOH). The outcomes demonstrated the excellent catalytic activity and selectivity of the complexes, which led to good yields of the intended products. As a result, the study offers useful information on the FePOphy complex’ synthetic uses, and the creation of effective and environmentally acceptable catalysts, and emphasizes their potential as powerful catalysts for a variety of organic transformations. This strategy’s simplicity, safety, commercially accessible catalyst, stability, fast reaction time, and outstanding yields may be used in the industry in the future.

Cobalt(III)–porphyrin Complex as an Efficient and Recyclable Homogeneous Catalyst for the Synthesis of Tetrahydro-2-oxa-4-thia-diazapentalen-5-one Derivatives in Aqueous Medium

Abstract: In this study, we successfully synthesized the CoPHrn complex as an efficient and recyclable catalyst for the one-pot, three-component reaction of aromatic aldehydes, 2,4-thiazolidenedione, and hydroxylamine hydrochloride, leading to the synthesis of tetrahydro- 2-oxa-4-thia-diazapentalen-5-one derivatives under environmentally friendly conditions. The structures of the newly formed compounds were determined through elemental and spectral analyses. This methodology offers significant advantages, including its ecofriendliness, cost-effectiveness, operational simplicity, extensive reusability, and applicability, as well as the easy recovery of the catalyst using straightforward methods. Additionally, a series of tetrahydro-2-oxa-4-thia-diazapentalen-5-one derivatives were successfully synthesized. Notably, this novel procedure demonstrates remarkable benefits in terms of safety, simplicity, stability, mild reaction conditions, short reaction times, excellent yields, and high purity, all achieved without the use of hazardous solvents.

A Catalyst Free Surfactant Mediated Multicomponent Synthesis of Quinazolinone Derivatives in Aqueous Media

A versatile and green synthetic protocol has been developed for synthesis of substituted quinazolinone and spiroquinazolinone heterocycles effectively via a combined surfactant mediated system. The use of Surfactant, water as reaction medium, room temperature, high yield and ease of purification made the process very effective and ecofriendly in nature. To demonstrate the wide scope of reaction Isatoic anhydride and Isatin used as reactants in different sets of reactions that leads to formation of Quinazolinones and spiroquinazolinones. A total of 12 derivatives has been prepared and characterized by all the spectroscopic data. The developed protocol presents a better and environmentally efficient methodology to get these heterocycles.

Iron-Catalyzed Biomimetic Dimerization of Tryptophan-Containing Peptides.

Biomimetic oxidative dimerization of tryptophan derivatives in aqueous media with oxygen as a bulk oxidant catalyzed by an iron octacarboxy phthalocyanine complex was established. The discovery of the extremely active iron catalyst enables aerobic enzyme-mimetic oxidation to be performed in a flask. This method was applicable to the oxidative dimerization of a wide range of tryptophan derivatives, including various dipeptides and oligopeptides, with remarkable functional-group tolerance without the protection of the amino acid residues. Furthermore, oxidative dimerization of tryptophan derivatives bearing dioxopiperazine units enabled the convergent total synthesis of five natural pyrroloindole compounds and unnatural congeners. The established chemical method provides facile access to a broad range of dimerized peptides with a unique scaffold to link two turn structures, which will serve as a powerful tool to create new small- and medium-sized-molecules as drug candidates.

Iron‐Catalyzed Biomimetic Dimerization of Tryptophan‐Containing Peptides

AbstractBiomimetic oxidative dimerization of tryptophan derivatives in aqueous media with oxygen as a bulk oxidant catalyzed by an iron octacarboxy phthalocyanine complex was established. The discovery of the extremely active iron catalyst enables aerobic enzyme‐mimetic oxidation to be performed in a flask. This method was applicable to the oxidative dimerization of a wide range of tryptophan derivatives, including various dipeptides and oligopeptides, with remarkable functional‐group tolerance without the protection of the amino acid residues. Furthermore, oxidative dimerization of tryptophan derivatives bearing dioxopiperazine units enabled the convergent total synthesis of five natural pyrroloindole compounds and unnatural congeners. The established chemical method provides facile access to a broad range of dimerized peptides with a unique scaffold to link two turn structures, which will serve as a powerful tool to create new small‐ and medium‐sized‐molecules as drug candidates.

A Systematic Study on the Redox Potentials of Phenazine-Derivatives in Aqueous Media: A Combined Computational and Experimental Work.

Phenazines are an emerging class of organic compounds that have been recently utilized in aqueous redox flow batteries, a promising technology for large-scale energy storage. A virtual screening based on density functional theory calculations is used to investigate the redox potentials of around 100 phenazine derivatives in aqueous media containing various electron-donating or electron-withdrawing groups at different positions. The calculations identify the crucial positions that should be functionalized with multiple hydroxy groups to design new anolytes. The combined experimental-computational methodology reported herein guides the development of a new molecule with a record low reversible redox potential as a potential anolyte for aqueous redox flow batteries.

A Systematic Study on the Redox Potentials of Phenazine- Derivatives in Aqueous Media: A Combined Computational and Experimental Work

A Systematic Study on the Redox Potentials of Phenazine- Derivatives in Aqueous Media: A Combined Computational and Experimental Work

Green chemistry approach: sodium fluoride-catalyzed highly efficient microwave irradiation-assisted synthesis of substituted chromene derivatives in aqueous medium

Green chemistry approach: sodium fluoride-catalyzed highly efficient microwave irradiation-assisted synthesis of substituted chromene derivatives in aqueous medium

A Facile and Efficient Synthesis of Indole Derivatives in Aqueous Media Catalyzed by [DMAP-SO3H]Cl and [DMAP-H]HSO4

A Facile and Efficient Synthesis of Indole Derivatives in Aqueous Media Catalyzed by [DMAP-SO3H]Cl and [DMAP-H]HSO4

Comparative quantitative kinetic study of rapid iodination of thiazole and its methyl derivatives in aqueous medium

AbstractThe study provides a quantitative framework for the assessment of the relative reactivity of thiazole and its two methyl derivatives namely 2‐methylthiazole and 4‐methylthiazole towards iodination reaction. Thiazole and its derivatives have a wide range of industrial and medicinal applications attributed to the ability of thiazole to manifest substituents around the core scaffold. The kinetic study of the iodination reactions of these substrates helps in the above applications since kinetics is an important investigational tool in configuring the mechanism of the reaction. In the present work, molecular iodine (I2) and iodine monochloride (ICl) were used as reagents for the iodination of thiazole, 2‐methylthiazole, and 4‐methylthiazole in aqueous medium. The iodination reactions are rapid electrophilic substitution reactions and hence special technique known as hydrodynamic voltammetry was employed for the kinetic study. Iodine is the only electro‐reducible species in the reactions. As the solution is devoid of iodide ions, a decrease in the concentration of iodine is measured in terms of diffusion current using a rotating platinum electrode with a saturated calomel electrode (SCE) as a reference electrode. The reactivity correlation of substrates towards iodination reaction was quantitively assessed by determining the reaction rate constants and thermodynamic parameters. The study shows overall rate of iodination of 4‐methylthiazole is faster than 2‐methylthiazole which is faster than thiazole. The study helps to develop a mechanistic approach considering the effect of substituent present on the thiazole ring. The order of reactivity of the reagents was determined based on obtained rate constants and explained owing to the nature of the reagent.

An eco-friendly method for the synthesis of 1,2,4-triazole-Schiff base derivatives in aqueous medium and DFT calculations

A detailed optimization study was carried out for the synthesis of 1,2,4-triazole-Schiff base derivatives. In previous studies, such reactions were performed either by conventional methods and using solvents such as ethanol, methanol, or THF in a microwave reactor for a certain period of time. However, in our study, the highest reaction yield was tried to be obtained by changing parameters such as temperature, time, and solvent system by using a monomode microwave reactor in aqueous medium. Thus, five novel 1,2,4-triazole-Schiff base derivatives were synthesized and characterized by FT-IR, NMR, and MS. Further, DFT (density functional theory) and AIM (atoms in molecules) calculations have been carried out to gain a better understanding of the molecular geometry, electronic properties, and chemical reactivity of the synthesized compounds. It was found that the pyrazole and phenyl groups of all compounds are almost in the same plane and that the benzotriazole ring is inclined by a torsion angle of 71.14 to 80.38° These molecular geometries exhibit at least three additional ring critical points (RCPs) resulting from three to five intramolecular contacts.

Novel high sensitivity dual-channel chemosensor for detecting CN− based on asymmetric azine derivatives in aqueous media

A novel cyanide specifically selective and highly sensitive chemosensor HSD had been designed and synthesized. • The synthesis process of HSD is simple and environmentally friendly. • HSD is shown “naked-eye” and fluorescence “turn-off” response for CN − in solution. • It has been applied to monitor CN − in an aqueous solution. • The mechanism of action of HSD on CN − is the deprotonate. • A test strip of HSD was prepared to detect CN − quickly and easily. Specific monitoring of trace levels of poisonous ions by naked eyes is still a significant challenge in the surroundings. Herein, we developed a novel asymmetric azine dual-channel sensor (HSD) applied for selectively detecting the CN − in the aqueous media. The selectivity and sensitivity of sensor HSD for anions sensing were investigated by measuring the photophysical properties. The results show that HSD recognizes CN − with good selectivity and sensitivity, with an “off” fluorescence response and apparent color change (from colorless to yellow) under visible light and strong anti-interference to other common anions. According to fluorescence titration of sensor HSD to CN − , the detection limit was determined to be as low as 1.02 × 10 −8 M. In addition, the reaction mechanism of the probe has been studied by 1 H NMR titration and DFT theoretical calculations. Finally, the test strips were prepared and verified to be a convenient and high-efficiency test kit for detecting CN − by naked eyes in the actual sample.