Synthesis, characterization, and biological evaluation of Schiff bases containing indole moiety and their derivatives

Green synthesis and investigation of antioxidant and antibacterial activity of new derivatives of chromenoazepines employing CuO/TiO2@MWCNTs

The synthesis of novel, high-yield derivatives of chromenoazepine was investigated in this work. CuO/TiO2@MWCNTs was used as a nanocatalyst in a multicomponent reaction involving 4-aminocumarine, activated acetylenic chemicals, and alkyl bromide in room temperature water to create these novel compounds. Using MCRs of 4-aminocumarine, isothiocyanate, and alkyl bromide in the presence of CuO/TiO2@MWCNTs as nanocatalysts in room-temperature water, chromenothiazepines were synthesized under comparable conditions. The freshly synthesized azepine exhibits antioxidant activity since its NH group has undergone two evaluation processes. Additionally, using two types of Gram-negative bacteria in a disk distribution procedure, the antibacterial activity of recently developed azepines was evaluated, and these compounds also inhibited the growth of Gram-positive bacteria. This method's benefits include quick reaction times, large product yields, and straightforward catalyst and product separation through easy steps.

Green preparation of new pyrimidine triazole derivatives via one-pot multicomponent reactions of guanidine

In this research the goal was to produce novel pyrimidine triazole compounds in high yields using triethylamin as an efficient catalyst. These new compounds were synthesized by using multicomponent reaction of aldehydes, guanidine, electron deficient acetylenic compounds, tert-butyl isocyanide and hydrazonoyle chloride in aqueous media. Due to the presence of an NH group, which was assessed using two different methodologies, newly synthesized pyrimidine triazoles have antioxidant properties. Additionally, the antibacterial activity of newly created pyrimidine triazoles was assessed using the disk distribution method with two different types of Gram-positive bacteria and Gram-negative bacteria, demonstrating that the use of these compounds prevented the growth of bacteria. Applied to the preparation of pyrimidine triazole derivatives, this method has short reaction times, high product yields, and the ability to separate catalyst and product using simple procedures.

Synthesis and evaluation of the antioxidant activity of new spiro-1,2,4-triazine derivatives applying Ag/Fe3O4/CdO@MWCNT MNCs as efficient organometallic nanocatalysts

We applied the Petasites hybridus rhizome water extract as green media so that Ag/Fe₃O₄/CdO@ multi-walled carbon nanotubes magnetic nanocomposites (Ag/Fe₃O₄/CdO@MWCNTs MNCs) could be prepared. We also evaluated its activity by using in the one-pot multicomponent reaction of acetophenones, diethyl oxalate, ammonium acetate, and activated carbonyl compounds such as ninhydrin, isatin and acenaphthylene-1,2-dione, and malononitrile and hydrazoyl chlorides in an aqueous medium at room temperature for the generation of spiro-1,2,4-triazines as new derivatives with tremendous output. Moreover, reducing organic pollutants from 4-nitrophenol (4-NP) was carried out by generating Ag/Fe₃O₄/CdO@MWCNTs in water at room temperature. The results displayed that Ag/Fe₃O₄/CdO@MWCNTs reduced pollutants of organic compounds in a short time. The synthesized spiro-1,2,4-triazines have NH and OH functional groups having acidic hydrogen with high antioxidant power. Also, the spiro-1,2,4-triazines exhibited antimicrobial ability. For this purpose, the disk diffusion method was applied and two kinds of bacteria, Gram-positive and Gram-negative, were employed for the analysis. Furthermore, we applied functional theory-based quantum chemical methods in order to better understand reaction mechanism density. To generate spiro-1,2,4-triazines, the applied process showed many properties such as reactions with short time, products with good yields, and simple extraction of catalyst from a mixture of reactions.

Six-component synthesis and biological activity of novel spiropyridoindolepyrrolidine derivatives: A combined experimental and theoretical investigation

Petasites hybridus rhizome water extract was used as green media for the preparation of Ag/Fe₃O₄/CdO@multi-walled carbon nanotubes magnetic nanocomposites (Ag/Fe₃O₄/CdO@MWCNTs MNCs), and its activity was evaluated by using in the one-pot multicomponent reaction of isatins, acetyl chloride, secondary amines, vinilidene Meldrum’s acid, primary amines, and malononitrile in an aqueous medium at room temperature for the generation of spiropyridoindolepyrrolidine as new derivatives with tremendous output. In addition, organic pollutant reduction of 4-nitrophenol (4-NP) was carried out by generated Ag/Fe₃O₄/CdO@MWCNTs in water at room temperature. The results displayed that Ag/Fe₃O₄/CdO@MWCNTs were reduced as pollutants of organic compounds in a short time. The synthesized spiropyridoindolepyrrolidine has an NH₂ functional group that has acidic hydrogen and shows high antioxidant ability. Also, the spiropyridoindolepyrrolidine exhibited antimicrobial ability, and the method that is used for this purpose is the disk diffusion method, and two kinds of bacteria, Gram-positive and Gram-negative, were employed for this analysis. Also, to better understand the reaction mechanism density, functional theory-based quantum chemical methods have been applied. For the generation of spiropyridoindolepyrrolidine, the used process has many properties such as reactions with short time, product with good yields, and simple extraction of catalyst from the mixture of reaction.

Synthesis of Antimicrobial Benzimidazole-Pyrazole Compounds and Their Biological Activities

The synthesis of new compounds with antimicrobial and antiviral properties is a central objective today in the context of the COVID-19 pandemic. Benzimidazole and pyrazole compounds have remarkable biological properties, such as antimicrobial, antiviral, antitumor, analgesic, anti-inflammatory, anti-Alzheimer's, antiulcer, antidiabetic. Moreover, recent literature mentions the syntheses and antimicrobial properties of some benzimidazole-pyrazole hybrids, as well as other biological properties thereof. In this review, we aim to review the methods of synthesis of these hybrids, the antimicrobial activities of the compounds, their correlation with various groups present on the molecule, as well as their pharmaceutical properties.

Ionic liquid as an effective green media for the synthesis of (5Z, 8Z)-7H-pyrido[2,3-d]azepine derivatives and recycable Fe3O4/TiO2/multi-wall cabon nanotubes magnetic nanocomposites as high performance organometallic nanocatalyst

In this research we investigated the preparation of new (5Z, 8Z)-7H-pyrido[2,3-d]azepine derivatives in high yields via multicomponent reaction of isatins, alkyl bromides, activated acetylenic compounds and ammonium acetate using ionic liquid 1-octhyl-3-methyl imidazolium bromide ([OMIM]Br) as a stabilizer and soft template at room temperature in the presence of Fe₃O₄/TiO₂/Carbon nanotubes magnetic nanocomposites as a reusable and effective nanocatalyst that are synthesized using ionic liquid [OMIM]Br as a stabilizer, soft template, green media and moderate base. Because of having a NH group in the synthesized pyridine derivatives, we investigate antioxidant property of some synthesized compounds by diphenyl-picrylhydrazine (DPPH) radical trapping and power of ferric reduction experiment. Short time of reaction, high yields of product, easy separation of catalyst and products are some advantages of this procedure.

Green Synthesis of 4H-pyran Derivatives Using Fe3O4-MNPs as Efficient Nanocatalyst: Study of Antioxidant Activity

Aims & Objective:

In this work, pyran derivatives were synthesized via a multicomponent reaction of ninhydrin, α-haloketones, dialkyl acetylenedicarboxylate, and triphenylphosphine in the presence of iron oxide magnetic nanoparticles (Fe3O4-MNPs) as efficient nanocatalyst in ethanol at room temperature.

Materials & Methods:

The biosynthesis of Fe3O4-MNPs was performed by Clover Leaf water extract. In addition, antioxidant activity was examined for the prepared compounds employing DPPH radical scavenging and ferric reduction activity potential (FRAP) experiment and comparing results with synthetic antioxidants (TBHQ and BHT).

Results:

Compound 5b showed excellent radical trapping activity and good reducing activity relative to standards (BHT and TBHQ).

Conclusion:

Some advantages of this procedure are: the workup of reaction is easy and the products can be separated easily by filtration. Fe3O4-MNPs display a good improvement in the yield of the product and showed significant reusable activity.

Bio-Fe3O4-MNPs catalyzed green synthesis of pyrrolo[2,1-a]isoquinoline derivatives using isoquinolium bromide salts: study of antioxidant activity

In this research, a novel, one-pot, efficient procedure with high yield for the synthesis of pyrrolo[2,1-a]isoquinoline derivatives using multi-component reaction of isoquinoline, alkyl bromides, and triphenylphosphine in the presence of Fe3O4-MNPs as catalyst under solvent-free conditions at room temperature is investigated. This study highlights an easy, simple, rapid, and clean method for the preparation of pyrrolo[2,1-a]isoquinoline derivatives. The Fe3O4-MNPs in these reactions were produced employing a green procedure by reduction of ferric chloride solution with pomegranate peel water extract. Additionally, antioxidant activity was studied for the some newly synthesized compounds such as 5a–5d using the DPPH radical trapping and reducing potential of ferric ion experiments and comparing the results with the results of synthetic antioxidants (2-tert-butylhydroquinone, TBHQ; butylated hydroxytoluene, BHT). As a result, compounds 5a–5d show trace DPPH radical trapping and excellent reducing power of ferric ion.

Copper iodide and ZnO nanoparticles catalyzed multicomponent synthesis of 1,3-cyclopentadiene: study of antioxidant activity

Zinc oxide (ZnO) nanoparticles, as a simple and recyclable catalyst, were easily synthesized and used for the synthesis of 1,3-cyclopentadiene derivatives by a four-component reaction of terminal alkynes, sulfonyl azides, activated acetylenic compounds, and isocyanides in the presence of copper iodide in acetonitrile at room temperature. In these reactions, 1,3-cyclopentadiene derivatives were obtained in good yield and in a short reaction time. In this research, antioxidant activity was investigated for the some newly synthesized compounds such as 5a–5d using the DPPH radical trapping and reducing potential tests of ferric ion and comparing results with synthetic antioxidants (TBHQ and BHT). In this study, compounds 5a–5d show good DPPH radical trapping and excellent reducing power of ferric ion.

Four-component green synthesis of benzochromene derivatives using nano-KF/clinoptilolite as basic catalyst: study of antioxidant activity

An efficient procedure for the synthesis of benzochromene derivatives employing 1-(6-hydroxy-2-isopropenyl-1-benzofuran-yl)-1-ethanone (euparin), aldehydes, alkyl bromides, dialkyl acetylenedicarboxylate and triphenylphosphine in the presence of KF/CP NPs as a heterogeneous base nano-catalyst in water at 80 °C is investigated. Also, the antioxidant activity of some synthesized compounds was studied. The workup of mixture of reaction is simple, and the products can be separated easily by filtration. KF/CP NPs showed a good improvement in the yield of the product and displayed significant reusable activity.

Green synthesis and antioxidant activity of novel series of benzofurans from euparin extracted of Petasites hybridus

A novel class of benzofuran derivatives is prepared from the isocyanide-based MCR, euparin and aldehydes in the presence of ZnO-nanorods as a catalyst in excellent yields at room temperature under solvent-free conditions as a green reaction medium. Also, the antioxidant activities of some synthesised compounds such as 4a, 4b, 10a and 10b were evaluated by DPPH radical scavenging and ferric reduction activity potential (FRAP) assays. Compound 10b, was shown moderate radical scavenging activity and very good reducing activity compared to standards (BHT and TBHQ).

Design, synthesis, and antifungal evaluation of novel 1,4-disubstituted 1,2,3-triazoles containing indole framework

In order to find novel bioactive compounds with significant antifungal activities, a series of novel 1,4-disubstituted 1,2,3-triazoles containing an indole ring via CuCl2/Zn-catalyzed Huisgen cycloaddition were designed, synthesized, and characterized. Antifungal activity against colletotrichum capsici and cotton physalospora pathogens of all the prepared compounds was evaluated, and the test results indicated that these compounds, especially 4g and 4h, showed significant inhibitory effects for fungi. All the synthesized compounds have been characterized by IR, NMR, and high-resolution mass spectra experiments. The preliminary structure activity relationship is also discussed in this paper.

A highly enantioselective thiolation of sulfonyl indoles to access 3-sec-sulfur-substituted indoles in water

Highly enantioselective organocatalytic Michael addition of thiol to vinylogous imine intermediates generated in situ from sulfonylindoles in aqueous medium is presented.