Acetylenic Compounds Research Articles

Investigation of the Performances of TiO2 and Pd@TiO2 in Photocatalytic Hydrogen Evolution and Hydrogenation of Acetylenic Compounds for Application in Photocatalytic Transfer Hydrogenation

Investigation of the Performances of TiO2 and Pd@TiO2 in Photocatalytic Hydrogen Evolution and Hydrogenation of Acetylenic Compounds for Application in Photocatalytic Transfer Hydrogenation

Efficient generation of novel phosphorus ylides via chemoselective and chemospecific reactions utilizing 2-(arylamino)-2-thioxoacetamide and methyl benzoylglycinates as precursors with activated acetylenic compounds

A chemospecific and chemoselective procedure has been developed for the efficient synthesis of novel phosphorus compounds, achieving moderate to excellent yields. This method involves the reaction of 2-(arylamino)-2-thioxoacetamide and methyl benzoylglycinate precursors with PPh3 in the presence of activated acetylenic esters. Notably, the reaction exhibits superior selectivity toward the NH2 group in 2-(arylamino)-2-thioxoacetamide, rather than the NH group. Moreover, when methyl benzoylglycinates are employed as a precursor, the reaction yields two distinct families of ylides, each with its own unique percentage yield.

Employing Cu@Fe3O4/SiO2@MWCNTs as New Catalyst for the Green Synthesis of New Pyridopyrroloindoles Using Multicomponent Reactions of Isatins

ABSTRACTBy using a multicomponent reaction involving isatins, diamines or aminoalcohols, activated acetylenic compounds, haloketones, and ammonium acetate in aqueous media in the presence of Cu@Fe3O4/SiO2@MWCNTs as new catalyst, the novel pyridopyrroloindole was produced in high yields. This catalyst was produced by employing Petasites hybridus rhizome water extract as a green media and moderate base. The pyridopyrroloindole derivatives were newly synthesized compounds, and their antioxidant properties were assessed using the 2,2‐diphenyl‐1‐picrylhydrazyl (DPPH) radical trapping and ferric reducing ability of plasma (FRAP) experiments. The pyridopyrroloindole 6b showed higher performance than butylated hydroxytoluene (BHT) and tert‐butylhydroquinone (TBHQ) better results. This method is used to make pyridopyrroloindole derivatives, and it has the advantages of a quick reaction, high yields, and the ability to separate the products easily.

Cu@Fe3O4/SiO2@MWCNTs promoted green synthesis of novel bis‐1,4‐dihydropyridines and evaluation of biological activity

This study examined the investigation of one‐pot multicomponent reactions of actylacetone, 4‐hydroxy‐3‐methoxybenzaldehyde, primary amines, and activated acetylenic compounds in an aqueous medium at room temperature in the presence of catalytic amounts of Cu@Fe3O4/SiO2@MWCNTs. The responses that were employed As a result, high‐yielding bis‐1,4‐dihydropyridines and other novel compounds can be produced. Diphenyl‐picrylhydrazine (DPPH) radical trapping is being used in this field of study to examine the antioxidant characteristics of some bis‐1,4‐dihydropyridines that are produced. Scholarly research now underway has concentrated on examining the antibacterial characteristics of chemical substances that have been produced. The bis‐1,4‐dihydropyridines was synthesized by an experimental procedure that demonstrated several notable features, such as rapid reaction kinetics, substantial product yields, and effortless separation of the catalyst from the reaction mixture.

Influence of Phosphorus Modifier and Nature of the Support on the Properties of Palladium Catalysts in the Chemoselective Hydrogenation of Acetylenic Compounds

Efficient heterogeneous catalysts for the chemoselective hydrogenation of terminal and disubstituted alkynes and alkynols to monoenes based on Pd–P particles have been proposed. The influence of a zeolite support (Na-ZSM-5, MCM-41) and a phosphorus modifier on the properties of palladium catalysts in the semihydrogenation of acetylenic compounds is considered. It has been shown that promotion with phosphorus increases the activity of palladium catalysts in the hydrogenation of various acetylenic compounds from 2.5 to 30 times without reducing the selectivity for monoenes. High selectivity for monoenes is determined by both thermodynamic and kinetic factors. Using the example of the acetylenic alcohol hydrogenation the possibility of changing the ratio of hydrogenation rates of triple and double bonds as a result of varying the solvent nature and the structural order of the catalyst particles was demonstrated.

Synthesis, Spectral and Electrochemical Properties, and Theoretical Studies of Highly Functionalized Fused Triazole-Isoindoline Derivatives as a Donor-Acceptor System

Triazole and propargyl group functionalities are frequently utilized in the construction of efficient blue-emitting materials, serving as acceptors and donors, respectively. Leveraging the synergistic effect of donor-acceptor coupling between these moieties, three new compounds, namely CB-But-I2, Ph-But-I2, and DP-But-I2, were synthesized. Given the advantageous strategy of combining electron donors and acceptors to optimize carrier injection and transport, CB-But-I2, Ph-But-I2, and DP-But-I2 demonstrate remarkable capabilities in both hole and electron transportation. A metal-free synthesis approach was employed to produce highly functionalized 1,2,3-triazole cores incorporating electronic donor and acceptor functionalities. This synthesis method involved the “Click reaction” ring formation between acetylene and azide compounds of 2-(4-bromobutyl) isoindoline-1,3-dione, catalyzed by copper sulfate pentahydrate and assisted by ascorbic acid as a base. The process boasts several advantages, including mild reaction conditions, accessibility of precursors, metal-free synthesis, straightforward setup, and the generation of various substituted regioselective triazole compounds in satisfactory yields. All synthesized compounds were found to possess thermal stability and exhibited fluorescence within the 292–355 nm range. Moreover, a significant positive solvato-chromic behavior was noted across different solvents with varying polarities, and the theoretical values were compared against experimental data for validation.

A highly effective method for the environmentally friendly production of novel chromene derivatives using electron deficient compounds

AbstractNew, high‐yield derivatives of oxepino[3,2‐c]chromene were synthesized through a multicomponent reaction. This reaction involved 2‐hydroxyacetophenone, dimethyl carbonate, activated acetylenic compounds, and alkyl bromide. The reaction took place at room temperature in an aqueous environment, resulting in the formation of these innovative compounds. Oxathiepines were synthesized using multicomponent reactions of 2‐hydroxyacetophenone, dimethyl carbonate, isothiocyanate, and alkyl bromide in water at room temperature. This technology offers several benefits, including quick response times, high product yields, and easy product separation using straightforward techniques.

Green synthesis of novel cyclopentapyridines: One‐pot multicomponent reactions of vinilydene Meldrum's acid

AbstractThis study focused on the investigation of synthesizing new derivatives of cyclopentapyridines with high yields employing multicomponent reaction that involved vinilydene Meldrum's acid, ethyl 2‐amino‐4‐dioxo‐4‐arylbutanoates, hydrazonoyl chlorides, and activated acetylenic compounds. The reaction was conducted in water at room temperature, resulting in the synthesis of new compounds. Also, the reaction of synthesized cyclopentapyridines with dimethyl acetylenedicarboxylate was performed in water at room temperature which produced other cyclopentapyridine derivatives by elimination of N2. The advantages of this technology encompass rapid response times, high product yields, and facile product separation via uncomplicated procedures.

WITHDRAWN: Green Synthesis and Evaluation of the Biological Activity of New Dihydropyridine Derivatives

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Investigation of the Biological Activity of Pyrrolo[1,2-a]imidazole Derivatives Produced by a Green One-Pot Multicomponent Synthesis of Ninhydrins

Aims & Objective: This study entailed the creation of a new variation of pyrroloimidazoles with exceptional efficacy through chemical synthesis. The synthesis was accomplished by tricomponent reactions utilizing ninhydrins, diamines, and activated acetylenic compounds in an aqueous setting, leading to significant yields. The antioxidant properties of recently synthesized Pyrroloimidazoles derivatives have been ascribed to the existence of NH and OH groups, which were evaluated using two techniques. The antimicrobial effectiveness of recently developed pyrroloimidazoles was evaluated using a disk diffusion technique against both Gram-negative and Gram-positive bacteria. Materials and Methods: The study team utilized high-quality starting chemicals, solvents, and reagents with consistent chemical and physical properties. The Shimadzu IR-460 spectrometer was used in a KBr medium to get the Ft-IR spectra of the synthesized nanocatalyst. Furthermore, we employed a Bruker DRX-400 AVANCE spectrometer to acquire 1H-NMR and 13C-NMR spectra of the synthesized compounds. The spectrometer utilized in this investigation functions at a frequency of 400 MHz. The solvent employed for the spectra of produced compounds was CDCl3, with TMS serving as the internal standard. The mass spectra of the produced compounds, which have an ionization potential of 70 eV, were obtained using the Finnigan MAT 8430 spectrometer. Elements of produced compounds were subjected to elemental analysis using the Heraeus CHN-O-Rapid analyzer. Results: This work investigated the three-component reaction involving ninhydrins 1, diamines 2, and electron-deficient acetylenic compounds 3 for the eco-friendly production of pyrroloimidazoles derivatives 4 in water-based solutions at normal temperature. The results indicated that these molecules displayed noteworthy efficacy, similar to that of conventional antioxidants. Also, the results indicated that the synthesized pyrroloimidazoles have bacteriostatic properties. Conclusion: In summary, this study aimed to examine the environmentally friendly characteristics of ninhydrins, diamines, and electron-deficient acetylenic compounds when dissolved in water at normal room temperature. The research resulted in the successful production of new pyrroloimidazole derivatives with a high rate of success. This study conducted a more in-depth analysis of the antioxidant properties of the synthesized pyrroloimidazoles 4a-4d by the utilization of two techniques: DPPH radical scavenging and FRAP assays. The results indicated that these molecules displayed noteworthy efficacy, similar to that of conventional antioxidants. Furthermore, we utilized both Gram-positive and Gram-negative bacteria to showcase the antibacterial effectiveness of the synthesized pyrroloimidazoles by the disk diffusion technique. The results indicated that the synthesized pyrroloimidazoles have bacteriostatic properties. These reactions provide benefits, such as efficient utilization of atoms, generation of large quantities of products, and straightforwardness of the reaction.

UPLC-ESI-MS/MS Profiling of Secondary Metabolites from Methanol Extracts of In Vivo and In Vitro Tissues of Daucus capillifolius Gilli (A Comparative Study).

Daucus capillifolius Gilli is a rare annual wild herb grown in Libya. It belongs to the Apiaceae family, which is one of the largest flowering plant families. Plants of this family are outstanding sources of various secondary metabolites with various biological activities. A UPLC-ESI-MS/MS analysis of different extracts of in vivo and in vitro tissues of Daucus capillifolius together with the fruit extract of the cultivated plant in both ionization modes was carried out for the first time in the current study. Our results reveal the tentative identification of eighty-seven compounds in the tested extracts, including thirty-two phenolic acids and their derivatives; thirty-seven flavonoid glycosides and aglycones of apigenin, luteolin, diosmetin, myricetin and quercetin, containing glucose, rhamnose, pentose and/or glucuronic acid molecules; seven anthocyanins; six tannins; three acetylenic compounds; and three nitrogenous compounds. The tentative identification of the above compounds was based on the comparison of their retention times and ESI-MS/MS fragmentation patterns with those previously reported in the literature. For this Apiaceae plant, our results confirm the presence of a wide array of secondary metabolites with reported biological activities. This study is among the first ones to shed light on the phytoconstituents of this rare plant.

Effects of Phosphorus Modifier and Support on the Properties of Palladium Catalysts in the Chemoselective Hydrogenation of Acetylenic Compounds

Effects of Phosphorus Modifier and Support on the Properties of Palladium Catalysts in the Chemoselective Hydrogenation of Acetylenic Compounds

Synthesis and biological evaluation of natural Lachnophyllum methyl ester, Lachnophyllum lactone and their synthetic analogs.

(2Z)-Lachnophyllum methyl ester and (4Z)-Lachnophyllum lactone were recently identified as major components in essential oils and extracts of Conyza bonariensis from Togo. Extended biological evaluation of these acetylenic compounds was however hampered by the reduced amounts isolated. A synthetic route was designed providing access to larger quantities of these two natural products as well as to original non-natural analogs with the prospect of exploring for the first time the structure-activity relationships in this series. Using LC/MS analysis, synthetic samples allowed confirming the presence of the two previously isolated natural products in plant extracts obtained by the accelerated solvent extraction technique. The nematocidal activity of the synthesized compounds confirmed the potency of the natural products, which remain the most active among all analogs tested. The synthesized compounds were also assessed against Leishmania infantum axenic amastigotes and the Mycobacterium tuberculosis H37Rv pathogenic strain. (2Z)-Lachnophyllum methyl ester, (4Z)-Lachnophyllum lactone and lactone analogs exhibited the strongest antileishmanial potency. As expected, a longer alkyl chain was necessary to observe significant antimycobacterial activity. The lactone analog bearing a C10 lipophilic appendage displayed the highest antimycobacterial potency. The notable activities of lactones, naturally occurring or analogs, either nematicidal, antileishmanial or antimycobacterial, were compared to their cytotoxicity for mammalian cells and revealed moderate selectivity index values. In this regard, the innocuous (2Z)-Lachnophyllum methyl ester and its analogs open up more promising perspectives for the discovery of bioactive agents to protect both agricultural crops and human health.

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.

Green Synthesis and Theoretical Study of New Imidazopyrimidine Derivatives via One‐Pot Multicomponent Reactions

AbstractAg/Fe3O4/SiO2@MWCNTs MNCs magnetic nanocomposites as an effective catalyst was employed for generating of imidazopyrimidine derivatives in high yields. The structure of synthesized nanoatalyst was confirmed by SEM, XRD, TEM, VSM, EDX and XPS analysis. These new compounds were synthesized by using multicomponent reaction of cyclic guanidine derivatives, electron deficient acetylenic compounds, tert‐butyl isocyanide, ethyl bromopyruvate and synthesized nanocatalyst in aqueous media at room temperature. It should be mentioned that the high performance of nanocatalyat was synthesized by using water extract of Petasits hybridus leaves, which was utilized in these reactions for many times to confirm the reusability of nanocatalyst. The antioxidant property of new synthesized imidazopyrimidine was evaluated by two procedures and compound 5 b have the high property relative to other compounds. Also, the antimicrobial activity of new generated imidazopyrimidine was evaluated by disk distribution process utilizing two kinds of Gram‐negative bacteria and Gram‐positive bacteria; proving bacterial growth was stopped by using of these compounds. Also, to better understanding reaction mechanism density functional theory (DFT) based quantum chemical methods have been applied. Applied to the preparation of imidazopyrimidine derivatives, this method has short reaction times, high product yields, and the ability to separate catalyst and product using simple procedures.

New MCRs: Preparation of Novel Derivatives of Pyrazoloazepines in Ionic Liquid and Study of Biological Activity

In the present investigation, we have effectively synthesized innovative pyrazoloazepine derivatives with notable yields. The synthesis was successfully accomplished by means of a multicomponent reaction that was carried out in an ionic liquid at ambient temperature conditions. The constituents implicated in this procedure consisted of NH-acids such as isatins, α-halo ketones, electron deficient acetylenic compounds, hydrazine, and hydrazonoyl chlorides. Significantly, the inclusion of an NH group appeared as a crucial characteristic in the resultant compounds. Our investigation encompassed the examination of the antioxidant capabilities exhibited by these substances. The study utilized various assays, including ferric reduction capacity and diphenyl-picrylhydrazine (DPPH) radical trapping, to investigate the possible antioxidant benefits of the substances. The antioxidative capacity of the produced pyrazoloazepine compounds was evaluated by various evaluations. The synthetic approach we employ offers numerous advantages. To begin with, the prompt response time enables the expedited generation of complex compounds. Furthermore, the significant outputs of the specific items highlight the effectiveness of our approach. The ease with which the catalyst and products can be separated enhances the efficiency of the purification procedure.

Green Synthesis and Biological Study of New Imidazothiazines Using New MCRs: A Combined Experimental and Theoretical Investigation

For the performing this research multicomponent reaction of isatin, electron-deficient acetylenic compounds, α-haloketones, ammonium acetate, isothiocyanates and methyl aziridine in aqueous at room temperature was investigated for the production of novel derivatives of azepinothiazine in excellent yields. The synthesized azepinothiazines have OH, NH2 and NH functional groups that have acidic hydrogen and show high antioxidant activity. These synthesized compounds also displayed antimicrobial activity by using the disk diffusion procedure and two Gram-positive and Gram-negative bacteria. Also, to better understanding reaction mechanism density functional theory-based quantum chemical methods have been applied. The employed process for the production of azepinothiazine has some benefits such as short time of reactions, excellent efficiency of the product, easy separation of products.

Green Synthesis of Five-Membered Hetarene N-Oxides: A Designed Approach to the Synthesis of Substituted Chromeno[3,4-c]pyrrole-2-oxides

AbstractAn efficient and chemoselective synthesis of biologically valuable chromeno[3,4-c]pyrrole 2-oxides containing one chiral stereocenter is described. In this method, by using a sequential nucleophilic addition reaction involving coumarins (α,β-unsaturated coumarins or 3-acetylcoumarins), activated acetylenic compounds, triphenylphosphine as a catalyst, and hydroxylammonium chloride (HAC) as an NO source, substituted chromeno[3,4-c]pyrrole 2-oxides were prepared with excellent efficiency. Readily available starting materials, absence of a metal catalyst, green and mild conditions, chemoselectivity, easy purification (the products can be purified by simple filtration and washing with EtOH), and synthetically useful yields are some highlighted advantages of this unprecedented transformation.

Green Synthesis of New Derivatives of Pyrrolopyrimidine by Employing Cu@KF/Clinoptilolite NPs: Study of Antioxidant Activity

In order to create Pyrrolo pyrimidine derivatives, multicomponent reactions involving butanoates, aldehydes, guanidine, activated acetylenic compounds, and ethyl bromopyruvate were carried out in water at room temperature with catalytic amounts of Cu@KF/CP NPs as a high-performance catalyst. Additionally, experiments involving the reducing power of ferric ions and radical trapping by DPPH were conducted to investigate the antioxidant capacity. As a result, the produced compounds exhibit excellent DPPH radical trapping and good ferric ion reduction capacity. The current method offers advantages including good reaction yield, green media, and simple product and catalyst separation.

Green Synthesis and Theoretical Study of New Azepinodiazepine Derivatives with Biological Activity: Application of Fe3O4/ZnO@MWCNT

In this study, we synthesized azepinodiazepine derivatives in high yields using multicomponent reactions of isatins, activated acetylenic compounds, alkyl bromides, methyl aziridine and ammonium acetate in the presence of Fe3O4/ZnO@MWCNT as a high-performance catalyst and teiethyl amine in water at room temperature. The Fe3O4/ZnO@MWCNT synthesizes using Petasites hybridus rhizome water extract as a green media and moderate base. Also, the catalytic activity of the green synthesized Fe3O4/ZnO@MWCNT MNCs was evaluated in the reduction of organic pollutants such as 4-nitrophenol (4-NP) in water at mild conditions. The results indicated that the biosynthesized NCs have very high and effective catalytic activity for organic pollutants within a few seconds. Investigation of the antioxidant ability of synthesized compounds using radical trapping of diphenyl-picrylhydrazine (DPPH) and ferric reduction power experiment is another purpose of this research. Also, the antimicrobial activity of some synthesized compounds was proved by employing the disk diffusion test on Gram-positive and Gram-negative bacteria. Also, to better understanding reaction mechanism density functional theory (DFT) based quantum chemical methods have been applied. This procedure has some benefits such as short reaction time, products with excellent yields, simple catalyst and product separation. Highlights Green chemistry is the use of a set of principles to reduce or eliminate the use or generation of unsafe materials in the design, fabrication and applications of chemical products. Among solvents, water is a green solvents and very suitable for performing organic reaction. The present procedure avoids the use of toxic solvent. Some representatives of this class of azaheterocycles are known as antiviral agents, glycosidase inhibitors, anticancer agents or antidiabetics. Therefore, in view of their medicinal relevance, an increasing number of synthetic methods have been described in recent years for the construction of highly substituted azepine derivatives.