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.

Carbon fixation of CO2 via cyclic reactions with borane in gaseous atmosphere leading to formic acid (and metaboric acid); A potential energy surface (PES) study.

Carbon dioxide (CO2), a stable gaseous species, occupies the troposphere layer of the atmosphere. Following it, the environment gets warmer, and the ecosystem changes as a consequence of disrupting the natural order of our life. Due to this, in the present reasearch, the possibility of carbon fixation of CO2 by using borane was investigated. To conduct this, each of the probable reaction channels between borane and CO2 was investigated to find the fate of this species. The results indicate that among all the channels, the least energetic path for the reaction is reactant complex (RC) to TS (A-1) to Int (A-1) to TS (A-D) to formic acid (and further meta boric acid production from the transformation of boric acid). It shows that use of gaseous borane might lead to controlling these dangerous greenhouse gases which are threatening the present form of life on Earth, our beautiful, fragile home.

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.

Green synthesis and investigation of antioxidant and antimicrobial activity of new schiff base of pyrimidoazepine derivatives: application of Fe3O4/CuO/ZnO@MWCNT MNCs as an efficient organometallic nanocatalyst.

In this study, we synthesized schiff base of pyrimidoazepine derivatives in high yields using multicomponent reactions of isatins, alkyl bromides, activated acetylenic compounds, guanidine and aldehydes in the presence of Fe3O4/CuO/ZnO@ Multi Walled Carbon Nanotubes (MWCNT) as a high performance catalyst in water at room temperature. The Fe3O4/CuO/ZnO@MWCNT synthesizes using Petasites hybridus rhizome water extract as a green media and moderate base. As well Fe3O4/CuO/ZnO@MWCNT magnetic nanocomposites show a good improvement in the yield of the product and displayed significant reusable activity. Investigation of antioxidant ability of synthesized compounds using radical trapping of diphenyl-picrylhydrazine and ferric reduction power experiment is another purpose in this research. Also, the antimicrobial activity of some synthesized compounds proved by employing the disk diffusion test on Gram-positive and Gram-negative bacteria. This procedure has some benefits such as short reaction time, product with excellent yields, simple catalyst and products separation.

Green novel multicomponent synthesis and biological evaluation of new oxazolopyrazoloazepines and reduction of nitrophenols in the presence of Ag/Fe3O4/ZnO@MWCNT MNCs.

In this research, new derivatives of oxazolopyrazoloazepines were synthesized in high yields using multicomponent reaction of anilines, oxalylchloride, alkyl bromides, activated acetylenic compounds, hydrazine and ethyl bromopyruvate in the presence of Ag/Fe3O4/ZnO@MWCNT magnetic nanocomposite (MNCs) as a high-performance magnetic catalyst in ionic liquid at room temperature. The Ag/Fe3O4/ZnO@MWCNT magnetic nanocomposites (MNCs) were synthesized using 1-octhyl-3-methyl imidazolium bromide ([OMIM]Br) as a stabilizer and soft template. Also, the catalytic activity of the Ag/Fe3O4/ZnO@MWCNT MNCs was evaluated in reduction of organic pollutants such as 4-nitrophenol (4-NP) in water at mild conditions. The results indicated that the biosynthesized nanocomposites (NCs) have high catalytic activity for organic pollutants within few seconds. Because of having benzazepine nucleus in the synthesized compounds, we investigate antioxidant property of some synthesized oxazolopyrazoloazepines by diphenyl-picrylhydrazine 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.

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.

PANI-Fe3O4@ZnO nanocomposite as magnetically recoverable organometallic nanocatalyst promoted synthesis of new Azo chromene dyes and evaluation of their antioxidant and antimicrobial activities.

A new series of azo chromene dyes were synthesized via a facile cyclocondensation reaction of (E)-1,2-diphenyl-1-diazene and 4-aminocoumarin with 1:2 molar ratio catalyzed by the polyaniline-Fe3O4@ZnO nanocomposite (PANI-Fe3O4@ZnO). The salient features of this protocol lie in simple experimental procedure, moderate reaction conditions, and uses PANI-Fe3O4@ZnO nanocomposite as a magnetically separable heterogeneous catalyst. Two well-known methods were employed for assessing the antioxidant abilities of the target compounds, including free radical trapping of 2,2-diphenyl-1-picrylhydrazyl (DPPH), as well as ferric reducing antioxidant power assay. Also, several synthesized compounds were screened for their in vitro antimicrobial activities by employing the disk diffusion test on Gram-negative as well as Gram-positive bacteria.

Ultrasound-promoted Green Synthesis of pyrido[2,1-a]isoquinoline Derivatives and Studies on their Antioxidant Activity.

Aims & Objective: An efficient procedure for the synthesis of pyrido[2,1-a]isoquinoline derivatives in excellent yields was investigated using catalyst-free multicomponent reaction of phthaladehyde, methylamine, activated acetylenic compounds, alkyl bromides and triphenylphosphine in water under ultrasonic irradiation at room temperature. In addition, Diels- Alder reactions of pyrido[2,1-a]isoquinoline derivatives with activated acetylenic compounds under ultrasonic irradiation are investigated in two procedures. The advantages of this procedure compared to report methods are short time of reaction, high yields of product, easy separation of product, clean mixture of reaction and green media for performing reaction. In addition, because of having isoquinoline core in synthesized compounds, in this research antioxidant activity of some synthesized compounds was studied. MATERIALS AND METHODS: To a stirred mixture of phthalaldehyde 1 (2 mmol) and methylamine 2 (2 mmol) in water (3 mL) under ultrasonic irradiation was added to activated acetylenic compounds 4 after 20 min. Alkyl bromide 3 and triphenylphosphine 5 react in another pot in water (3 mL) under ultrasonic irradiation for 15 min. After this time, this mixture was added to the first pot. After completion of the reaction, the solid residue was separated by filtration and washed with Et2O to afforded pure title compound 6. RESULTS: In this work, generation of pyrido[2,1-a]isoquinoline derivatives 6 are performed using phthalaldehyde 1, methylamine 2, α-halo substituted carbonyls 3, activated acetylenic compounds 4 and triphenylphosphine 5 in water under ultrasonic irradiation condition at room temperature in excellent yield at short time. CONCLUSION: In summary, multicomponent reaction of phthaladehyde, methylamine, activated acetylenic compounds, alkyl bromides and triphenylphosphine in water under ultrasonic irradiation at room temperature produced pyrido[2,1-a]isoquinoline derivatives in excellent yields. Also, Diels-Alder reaction of pyrido[2,1-a]isoquinoline derivatives with activated acetylenic compounds and triphenylphosphine under ultrasonic irradiation is investigated in two procedures. Also, the antioxidant activities of 6a, 6c, 6g and 6i were evaluated by DPPH radical scavenging and ferric reducing power analyzes. The compounds 6a exhibit excellent DPPH radical scavenging activity and FRAP compared to synthetic antioxidants BHT and TBHQ. The chief benefits of our method are high atom economy, green reaction conditions, higher yield, shorter reaction times, and easy work-up, which agree with some principles of green chemistry.

Production of benzazepine derivatives via four-component reaction of isatins: study of antioxidant activity.

In current research, benzazepine derivative is synthesized via a new process of four-component reaction of isatin or its derivatives, α-haloketones, activated acetylenic compounds, isoquinoline and potassium fluoride/clinoptilolite nanoparticles (KF/CP NPs) in acidic solution of H2O2 in water at room temperature. Also, antioxidation property of some prepared benzazepines is investigated by employing trapping diphenyl-picrylhydrazine (DPPH) radical and ability of ferric reduction experiment. Among investigated compounds, compounds 5c have good results relative to BHT and TBHQ as standard antioxidant. Also, the Gram-positive and Gram-negative bacteria disk diffusion research is used for the confirmation of antimicrobial power of some prepared benzazepines. The achieved outcomes of disk diffusion experiment showed that these compounds avoided the growth of bacteria. Our procedure has a few benefits relative to reported method such as good rate of reaction, product with high efficiency, simple removal of catalyst from mixture of reaction. In the yield of the product, KF/clinoptilolite nanoparticles show a satisfactory recyclable activity.

Synthesis, computational study and cytotoxicity of 4-hydroxycoumarin-derived imines/enamines.

In this study, we applied a direct condensation between 3-acetyl-4-hydroxy-2H-chromen-2-one and different amines (anilines and benzyl amines) in order to synthesize some coumarin-based imines/enamines (3a-o) as cytotoxic agents. All the compounds were characterized by means of FT-IR, NMR, mass spectroscopy and elemental analyses. Since the title compounds can exist as different forms including (s-cis)-imine and (s-trans)-imine or (E and Z)-enamines, their conformational and geometrical aspects were investigated computationally by DFT method. The optimized geometry parameters, ΔE, ΔG, ΔH, Mulliken atomic charge, HOMO and LUMO energy, and NBO analysis suggested that these compounds can exist predominantly in (E)-enamine form. All the synthesized compounds (3a-o) were evaluated in vitro for their cytotoxic activities against cancer cell lines (MCF-7 and A549) and normal cell line (BEAS-2B) using the MTT assay. The 4-hydroxybenzyl derivative 3k was found to be the most potent cytotoxic agent with no selectivity, similar to doxorubicin. However, the 4-chlorobenzyl analog 3o could be considered as an equipotent compound respect to doxorubicin with higher selectivity.

Intermolecular difunctionalization of alkenes: synthesis of ß-hydroxy sulfides.

Direct difunctionalization of carbon-carbon double bonds is one of the most powerful tools available for concomitant introduction of two functional groups into olefinic substrates. In this context, vicinal hydroxysulfenylation of unactivated alkenes has emerged as a novel and straightforward strategy for the fabrication of ß-hydroxy sulfides, which are extremely valuable starting materials in constructing various natural products, pharmaceuticals, and fine chemicals. The aim of this review is to summarize the most representative and important reports on the preparation of ß-hydroxy sulfides through intermolecular hydroxysulfenylation of the corresponding alkenes with special emphasis on the mechanistic features of the reactions.

Hydroxysulfonylation of alkenes: an update.

The direct difunctionalization of inexpensive and widely available alkenes has been recognized as a strong and straightforward tool for the rapid fabrication of complex molecules and pharmaceutical targets by introducing two different functional groups on adjacent carbon atoms of common alkene moieties in a single operation. This synthetic strategy avoids the purification and isolation of the intermediates and thus makes synthetic schemes shorter, simpler and cleaner. In this family of reactions, the hydroxysulfonylation of alkenes has emerged as an increasingly promising strategy for the synthesis of ß-hydroxysulfones, which are found in many biologically important molecules and widespread applications in organic synthesis. The objective of this review is to illustrate the advancements in the field of hydroxysulfonylation of alkenes with special emphasis on the mechanistic details of the reaction pathways.

3,5-Bis(trifluoromethyl) Phenylammonium triflate(BFPAT) as a Novel Organocatalyst for the Efficient Synthesis of 2,3-dihydroquinazolin-4(1H)-one Derivatives.

AIMS AND OBJECTIVES: A one-pot synthesis of 2,3-dihydroquinazolin-4(1H)-one derivatives by threecomponent cyclo-condensation of isatoic anhydride, aldehydes and amine or ammonium acetate has been developed using 3,5-Bis(trifluoromethyl) phenylammonium triflate (BFPAT) as a new organocatalyst. MATERIALS AND METHODS: All of the obtained products are known compounds and identified by IR, 1HNMR, 13CNMR and melting points. RESULTS: A wide variety of structurally different aldehydes reacted easily and rapidly to result in the relating 2,3-dihydroquinazolin-4(1H)-ones in good to excellent yield. CONCLUSION: We have demonstrated an extremely effective and new process for synthesizing 2,3- dihydroquinazolin-4(1H)-ones employing BFPAT as a novel organocatalyst in one-pot fashion.

ZnO-nanorods Promoted Synthesis of α-amino Nitrile Benzofuran Derivatives using One-pot Multicomponent Reaction of Isocyanides.

AIMS AND OBJECTIVE: In this work ZnO-nanorod (ZnO-NR) as reusable catalyst promoted Strecker-type reaction of 2,4-dihydroxyacetophenone, isopropenylacetylene, trimethylsilyl cyanide (TMSCN), primary amines and isocyanides at ambient temperature under solvent-free conditions and produced α-amino nitriles benzofuran derivatives in high yields. These synthesized compounds may have antioxidant ability. MATERIALS AND METHODS: ZnO-NRs in these reactions were prepared according to reported article. 2,4-dihydroxyacetophenone 1 (2 mmol) and isopropenylacetylene 2 (2 mmol) were mixed and stirred for 30 min in the presence of ZnO-NR (10 mol%) under solvent-free conditions at room temperature. After 30 min, primary amine 3 (2 mmol) was added to the mixture gently and the mixture was stirred for 15 min. After this time TMSCN 4 (2 mmol) was added to the mixture and stirred for 15 min. After completion of the reaction, as indicated by TLC, isocyanides 5 was added to mixture in the presence of catalyst. RESULTS: In the first step of this research, the reaction of 2,4-dihydroxyacetophenone 1, isopropenylacetylene 2, methyl amine 3a, trimethylsilyle cyanide 4 and tert-butyl isocyanides 5a was used as a sample reaction to attain the best reaction conditions. The results showed this reaction performed with catalyst and did not have any product without catalyst after 12 h. CONCLUSION: In conclusion, we investigate multicomponent reaction of 2,4-dihydroxyacetophenone 1, isopropenylacetylene 2, primary amines 3, trimethylsilyl cyanide 4 and isocyanides along with ZnO-NRs as reusable catalyst at room temperature under solvent-free conditions which generates α-amino nitrile benzofuran derivatives in high yields. The advantages of our method are high atom economy, green reaction conditions, higher yield, shorter reaction times, and easy work-up, which are in good agreement with some principles of green chemistry. The compounds 8c exhibit excellent DPPH radical scavenging activity and FRAP compared to synthetic antioxidants BHT and TBHQ.

Ionic Liquid-assisted Preparation of Two-dimensional ZnO/Fe3O4 Nano-composites and their Application in Polysubstituted Pyrroles Synthesis.

AIMS AND OBJECTIVE: Ionic liquids are a suitable medium for stabilization and preparation of catalytic systems. MATERIALS AND METHODS: The two-dimensional (2D) ZnO/Fe3O4 nanocomposites were synthesized using ionic liquid [OMIM]Br as a stabilizer and soft template. The nanocomposites were characterized via FTIR, XRD, VSM and SEM analysis. RESULT: The catalytic activity of these composites was evaluated using a multicomponent reaction of primary amines, acetylacetone, and 2-bromoacetophenone. CONCLUSION: 2D ZnO/Fe3O4 as a recyclable and green catalyst showed excellent catalytic performance for the preparation of poly-substituted pyrroles.

A novel one-pot three-component synthesis of benzofuran derivatives via Strecker reaction: Study of antioxidant activity.

A three-component Strecker-type reactions was applied for the synthesis of benzofuran derivatives through the reaction of 1-(6-hydroxy-2-isopropenyl-1-benzofuran-yl)-1-ethanone (euparin), primary amines and trimethylsilyl cyanide (TMSCN) in the presence of catalytic amount of ZnO-nanorods (ZnO-NR) and piperidine in acetonitrile at room temperature. The method has proved to be synthetically simple, and effective with high atom economy and yield. The catalyst also revealed significant reusability. Moreover, the antioxidant activity and free radical scavenging capacity of the newly synthesized such as 4a, 4c, 6a and 6c was screened using free radical scavenging 2,2-diphenyl-1-picrylhydrazyl (DPPH) and ferric reducing antioxidant power (FRAP) assays and compared with hydroxytoluene (BHT) and tert-butylhydroquinone (TBHQ). These compounds exhibit good DPPH radical scavenging and ferric reducing antioxidant power (FRAP) assays.

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.

Fe3O4 MNPs as a green catalyst for syntheses of functionalized [1,3]-oxazole and 1H-pyrrolo-[1,3]-oxazole derivatives and evaluation of their antioxidant activity.

In the present study, iron oxide magnetic nanoparticles (Fe3O4 MNPs) were synthesized in a green biosynthetic manner using aqueous extract of clover leaves. Fe3O4 MNPs were applied as a magnetically separable nanocatalyst for the green syntheses of functionalized [1,3]-oxazoles 1(a-e) and 1H-pyrrolo-[1,3]-oxazoles 4(a-i) as promising antioxidant compounds in excellent yields at 50 °C and room temperature, respectively. The antioxidant activities of the most stable compounds (1a, 1b, 4a, and 4b) were evaluated by both 2,2-diphenyl-1-picrylhydrazyl radical scavenging and ferric reduction activity potential assays. Compound 1b was shown a remarkable radical scavenging activity, and 4a was shown very good reducing activity relative to standards (BHT and TBHQ).