Synthesis Of Organic Compounds Research Articles

Synthesis, spectroscopic analysis and electrochemical studies of novel organic compound based on N-alkylphthalazinone chemistry as corrosion inhibitor for carbon steel in 1M HCl

The adsorption affinity and corrosion protection of two synthesized N-alkylphthalazinone derivatives 2(a-b), namely: 2-(prop-2-yn-1-yl)-4-(p-tolyl)phthalazin-1(2H)-one (a) and 4-(4-chlorophenyl)-2-(prop-2-yn-1-yl)phthalazin-1(2H)-one (b) on carbon steel (CS) in an acidic environment using electrochemical and mass loss methods. The mass loss test at the highest inhibitor concentration produced a maximum corrosion efficiency of 93.4% for inhibitor (a). Thermodynamic parameters were determined while the inhibitors' adsorption process was investigated. The inhibitory molecules adsorption on the CS substrate accompanied the Langmuir isotherm. As a function of inhibitor concentration, the thermodynamic activation functions of the dissolution process were calculated. Surface examination such as scanning electron microscopy (SEM), fourier transfer infrared spectroscopy (FTIR), and atomic force microscopy (AFM) techniques were used to confirm the adsorption phenomenon. Also investigated were quantum chemical parameters to approve the donor-acceptor system of the synthesized N-alkylphthalazinone derivatives. The theoretical values are in good correlation with the experimental values.

Asymmetric Synthesis of Chiral Sulfimides through the O-Alkylation of Enantioenriched Sulfinamides and Addition of Carbon Nucleophiles.

Chiral sulfimides, the aza-analogues of sulfoxides, are valuable compounds in organic synthesis and medicinal chemistry. Herein, we report an efficient method for preparing chiral sulfimides from easily available enantioenriched sulfinamides. The key step of this method is a stereospecific oxygen-selective alkylation of enantioenriched sulfinamides, which is accomplished by using isopropyl iodide, K2 CO3 , and DMPU. The resulting chiral sulfinimidate esters are transformed to chiral sulfimides by the nucleophilic addition of the Grignard reagents under simple conditions. This transformation enables access to the enantioenriched diaryl or dialkyl sulfimides bearing two similar carbon substituents, which are difficult to synthesize by previous methods.

Asymmetric Synthesis of Chiral Sulfimides through the O‐Alkylation of Enantioenriched Sulfinamides and Addition of Carbon Nucleophiles

AbstractChiral sulfimides, the aza‐analogues of sulfoxides, are valuable compounds in organic synthesis and medicinal chemistry. Herein, we report an efficient method for preparing chiral sulfimides from easily available enantioenriched sulfinamides. The key step of this method is a stereospecific oxygen‐selective alkylation of enantioenriched sulfinamides, which is accomplished by using isopropyl iodide, K2CO3, and DMPU. The resulting chiral sulfinimidate esters are transformed to chiral sulfimides by the nucleophilic addition of the Grignard reagents under simple conditions. This transformation enables access to the enantioenriched diaryl or dialkyl sulfimides bearing two similar carbon substituents, which are difficult to synthesize by previous methods.

Towards Green Reductions in Bio‐Derived Solvents

AbstractThe hydrogenation processes, and all the reactions that formally add two hydrogen atoms to an unsaturated bond, are among the most used transformations in the manufacture of bulk and fine chemicals. Although their potential as powerful tool for the sustainable synthesis of organic compounds, hydrogenations, and more generally the reductions, have been typically carried out in volatile organic solvents deriving from petroleum; indeed, all studies and fascinating advances related to the catalysts’ activity or the reducing agents’ reactivity have been limited to such volatile and often toxic reaction media. In this review, recent advances in the reducing methodologies with an improved degree of sustainability have been described. In particular, a series of examples have been reported to highlight the chance to reduce an organic compound by using a benign solvent deriving from renewable sources, without waiving to the process efficiency and selectivity. Some important key points of green chemistry, such as the easiness of catalyst recovery or the simplicity of product isolation, have been considered in the choice of the described studies.

Polyfunctionalization of vicinal carbon centers and synthesis of unsymmetric 1,2,3,4-tetracarbonyl compounds

The synthesis and characterization of organic compounds with unusual atom or functional group connectivity is one of the main driving forces in the discovery of new synthetic methods that has raised the interest of chemists for many years. Polycarbonyl compounds are such compounds wherein multiple carbonyl groups are directly juxtaposed and influence each other’s chemical reactivity. While 1,2-dicarbonyl or 1,2,3-tricarbonyl compounds are well-known in organic chemistry, the 1,2,3,4-tetracarbonyl motif remains barely explored. Herein, we report on the synthesis of such 1,2,3,4-tetracarbonyl compounds employing a synthetic strategy that involves C-nitrosation of enoldiazoacetates, while the diazo functional group remains untouched. This strategy not only leverages the synthesis of 1,2,3,4-tetracarbonyl compounds to an unprecedented level, it also accomplishes the synthesis of 1,2,3,4-tetracarbonyl compounds, wherein each carbonyl group is orthogonally masked. Combined experimental and theoretical studies provide an understanding of the reaction mechanism and rationalize the formation of such 1,2,3,4-tetracarbonyl compounds.

Novel neodymium complex on MCM‐41 magnetic nanocomposite as a practical, selective, and returnable nanocatalyst in the synthesis of tetrazoles with antifungal properties in agricultural

This project reports a simple procedure for the synthesis and characterization of neodymium on MCM‐41 magnetic nanoparticles (MNPs) as a reusable nanocatalyst. First, magnetite (Fe3O4) MNPs were prepared by chemical co‐precipitation procedure from FeCl3 hexahydrate and FeCl2 tetrahydrate in basic NH3 solution. At the second step, MCM‐41 magnetic nanocomposite (MCM‐41 MNC) was prepared by Fe3O4 doping into mesoporous MCM‐41 channels. At the third step, a novel neodymium Schiff base complex was immobilized on MCM‐41 MNC. At the fourth step, this catalyst (Nd‐LArg‐5BrSalen@MNC) was used as practicable and magnetically recoverable nanocatalyst in the homoselective synthesis of tetrazoles. This nanocatalyst was characterized via several analysis, for example, TGA, TEM, UV, SEM, FT‐IR, SEM‐EDS, VSM, ICP, XRD, WDX, and BET. All tetrazole products were synthesized with high yield in a short time. Despite high catalytic activity of neodymium, it has rarely used as a catalyst in the synthesis of organic compounds. All synthesized organic compounds were identified by 1H NMR, FT‐IR, and physical properties. Nd‐LArg‐5BrSalen@MNC nanocatalyst displays high activity, good selectivity, stability, and more important facile magnetic separation. Nd‐LArg‐5BrSalen@MNC nanocatalyst can be isolated and used again for several times consecutively without considerable loss of its catalytic activity. The recycled catalyst was characterized by SEM, EDS, WDX, XRD, and FT‐IR techniques and showed a good match with the fresh catalyst. Also, the antifungal activity of the some tetrazole derivatives was studied against Fusarium oxysporum (rot disease of chickpea root) and Botrytis cinerea (gray mold of strawberry) using the paper disk method on PDA culture medium.

Thermo-neutrophilic cellulases and chitinases characterized from a novel putative antifungal biocontrol agent: Bacillus subtilis TD11.

Cellulose and chitin are the most abundant naturally occurring biopolymers synthesized in plants and animals and are used for synthesis of different organic compounds and acids in the industry. Therefore, cellulases and chitinases are important for their multiple uses in industry and biotechnology. Moreover, chitinases have a role in the biological control of phytopathogens. A bacterial strain Bacillus subtilis TD11 was previously isolated and characterized as a putative biocontrol agent owing to its significant antifungal potential. In this study, cellulase and chitinase produced by the strain B. subtilis TD11 were purified and characterized. The activity of the cellulases and chitinases were optimized at different pH (2 to 10) and temperatures (20 to 90°C). The substrate specificity of cellulases was evaluated using different substances including carboxymethyl cellulose (CMC), hydroxyethyl cellulose (HEC), and crystalline substrates. The cellulase produced by B. subtilis TD11 had a molecular mass of 45 kDa while that of chitinase was 55 kDa. The optimal activities of the enzymes were found at neutral pH (6.0 to 7.0). The optimum temperature for the purified cellulases was in the range of 50 to 70°C while, purified chitinases were optimally active at 50°C. The highest substrate specificity of the purified cellulase was found for CMC (100%) followed by HEC (>50% activity) while no hydrolysis was observed against the crystalline substrates. Moreover, it was observed that the purified chitinase was inhibitory against the fungi containing chitin in their hyphal walls i.e., Rhizoctonia, Colletotrichum, Aspergillus and Fusarium having a dose-effect relationship.

Selective indirect electrochemical oxidation of sulfides and thiols using DDQ as an efficient and cost-effective electrocatalyst

The efficient oxidation of sulfides to sulfoxides and the oxidative coupling of thiols to disulfides was performed electrochemically in the presence of DDQ as an electrocatalyst. The electrochemical reactions were conducted in a mixture of water and acetonitrile as solvent under constant potential (0.6 V vs Ag/AgCl) for regeneration of DDQ at room temperature and the products were selectively produced in good to high yields. The electrocatalytic properties of the applied electrocatalyst for the oxidation of substrates and the proposed electrocatalytic mechanism were investigated by the cyclic voltammetry (CV) technique. The proposed electrochemical regeneration of DDQ can be developed for the synthesis of different organic compounds in a single operation under mild conditions

Poly(Glycerol)-Based Biomedical Nanodevices Constructed by Functional Programming on Inorganic Nanoparticles for Cancer Nanomedicine

Nanomedicine is promising to improve conventional cancer medicine by making diagnosis and therapy more accurate and more effective in a more personalized manner. A key of the cancer nanomedicine is construction of medical nanodevices by programming various requisite functions to nanoparticles (NPs). As compared to that of soft NPs, including organic micelles and polymers, fabrication of an inorganic NP based nanodevice is still challenging; the approved nanoformulations have been confined to the limited number of superparamagnetic iron oxide NPs (SPIONs). The major challenges lie in how to program the requisite functions to inorganic NPs. In spite the much denser and less hydrophilic properties of inorganic NPs, most of the following functions have to be programmed for their in vivo applications: (A) high dispersibility in a physiological environment, (B) high stealth efficiency to slip through the trap by liver and spleen, (C) high targeting efficiency to cancer tissue, (D) clear visualization of cancer for diagnosis, and (E) high anticancer activity for treatment.In our approach, poly(glycerol) (PG), containing a hydroxy group at every monomer unit, was found as a better alternative to poly(ethylene glycol) (PEG), the most commonly used hydrophilic polymer, giving (A) high dispersibility to inorganic NPs. Although most of the inorganic NPs are not dense in functional groups, the hyperbranched structure with many hydroxy groups in PG turns the less functional surface into highly functional one, imparting not only good hydrophilicity but also (B) high stealth efficiency as we reported recently. In addition, a number of hydroxy groups in PG afford the structural or functional extensibility to introduce the additional layer or function. This enables us to design and construct a three-layer architecture consisting of a core inorganic NP, a hydrophilic and stealthy PG layer, and a functional molecule layer, where their interfaces are connected firmly by covalent bonds. The three-layered nanodevice is very flexible in its design for the following reasons: The PG coating can be applied to a wide variety of inorganic NPs with various functions, and various functional moieties can be introduced on the PG layer as a functional molecule layer. Owing to the versatility of the three-layer model, the rest of the above functions (C)-(E) can be programed in the NP core and/or the outmost layer in nanodevices.In this Account, the author described first the methodology for precise construction and quantitative characterization of various biomedical nanodevices. This fundamental aspect of this research has been achieved by "applying organic chemistry to nanomaterials" which is the concept of our research. That is, the rich chemistry in synthesis and characterization of organic compounds has been applied to the nanodevice fabrication and characterization. Second, evaluation of the functions programmed in the nanodevices is described in terms of stealth and targeting efficiencies, cancer diagnosis and therapy, and biomedical sensing. This stage in our research made us more interdisciplinary from chemistry and nanoscience to biology and medicine. The following research spiral has been established in our group to strongly promote the improvement of our biomedical nanodevices; nanodevice design → precise construction → quantitative characterization → functional evaluation.

The use of organoelement compounds of some elements of groups III, V and peroxides in the synthesis of organic compounds and polymers. In memory of professor V.A. Dodonov

The use of organoelement compounds of some elements of groups III, V and peroxides in the synthesis of organic compounds and polymers. In memory of professor V.A. Dodonov

Research Progress in the Synthesis of Cyclic Organic Compounds Using Bimetallic Relay Catalytic Strategies

Research Progress in the Synthesis of Cyclic Organic Compounds Using Bimetallic Relay Catalytic Strategies

Unleashing the solar revolution: harnessing the power of an ultra-strong tensile strength PGTPP nanocomposite photocatalyst for artificial photosynthesis

Indeed, natural photocatalysis is a highly promising approach for renewable energy production and the synthesis of cost-effective organic compounds.

A post-sulfonated one-pot synthesized magnetic cellulose nanocomposite for Knoevenagel and Thorpe-Ziegler reactions.

The development of biodegradable and active cellulosic-based heterogeneous catalysts for the synthesis of different organic compounds would be attractive in pharmaceutical and petrochemical-related industries. Herein, a post-sulfonated composite of one-pot synthesized magnetite (Fe3O4) and cellulose nanocrystals (CNCs) was used as an effective and easily separable heterogeneous catalyst for activating the Knoevenagel and Thorpe-Ziegler reactions. The composite was developed hydrothermally from microcrystalline cellulose (MCC), iron chlorides, urea, and hydrochloric acid at 180 °C for 20 h in a one-pot reaction. After collecting the magnetic CNCs (MCNCs), post-sulfonation was performed using chlorosulfonic acid (ClSO3H) in DMF at room temperature producing sulfonated MCNCs (SMCNCs). The results confirmed the presence of sulfonated Fe3O4 and CNCs with a hydrodynamic size of 391 nm (±25). The presence of cellulose was beneficial for preventing Fe3O4 oxidation or the formation of agglomerations without requiring the presence of capping agents, organic solvents, or an inert environment. The SMCNC catalyst was applied to activate the Knoevenagel condensation and the Thorpe-Ziegler reaction with determining the optimal reaction conditions. The presence of the SMCNC catalyst facilitated these transformations under green procedures, which enabled us to synthesize a new series of olefins and thienopyridines, and the yields of some isolated olefins and thienopyridines were up to 99% and 95%, respectively. Besides, the catalyst was stable for five cycles without a significant decrease in its reactivity, and the mechanistic routes of both reactions on the SMCNCs were postulated.

Design, Synthesis and Evaluation of Some Substituted Triazole Phenyl Methanones from Substituted Anilines

Triazoles, a five-membered ring structure and three nitrogen atoms, are regarded as important building blocks for the synthesis of numerous organic compounds. Triazoles and their derivatives have received considerable attention over the past decade due to their chemotherapeutic value. It’s been thought to be a functional core that exhibits most varieties of biological activity mainly antibiotics, antimicrobials and antifungals. In present work, a series of novel substituted triazole phenylmethanones were synthesized using Claisen-Schmidt condensation reaction of 1-(5-methyl-1-(substituted phenyl)-1H- 1,2,3-triazol-4-yl)-ethan-1-one (3a-d) and some aromatic aldehydes. Final compounds (5a-f) were synthesized from compounds 4a-d, hydrazine hydrate and benzoic acid by sequential reactions having intermolecular conjugate addition and formation of hydrazone. All the intermediate and final compounds were characterized from the mass, elemental and 1H NMR spectral data.

Exploring the role of solvent polarity in mechanochemical Knoevenagel condensation: in situ investigation and isolation of reaction intermediates.

Mechanochemistry has proven to be a highly effective method for the synthesis of organic compounds. We studied the kinetics of the catalyst-free Knoevenagel reaction between 4-nitrobenzaldehyde and malononitrile, activated and driven by ball milling. The reaction was investigated in the absence of solvents (neat grinding) and in the presence of solvents with different polarities (liquid-assisted grinding). The reaction was monitored using time-resolved in situ Raman spectroscopy and powder X-ray diffraction (PXRD). Our results indicate a direct relationship between solvent polarity and reaction kinetics, with higher solvent polarity leading to faster product (2-(4-nitrobenzylidone)malononitrile) formation. For the first time, we were able to isolate and determine the structure of an intermediate 2-(hydroxy(4-nitrophenyl)methyl)malononitrile based on PXRD data.

Синтез и исследование строения 2-алкенилсульфанил-1-метилимидазолов

Derivatives of 1-methylimidazole-2-thiol (1) bearing substituents of various kinds are prom-ising ligands for modeling various enzymatic systems and structures with pharmacological activity. They are widely used as intermediates in the synthesis of organic compounds possessing biological activity (antitumor, antimicrobial, antidiabetic, antithyroid, antihistamine, antiprotozoal, and antiviral) as well as agrochemicals, dyes, photochemicals, corrosion inhibitors, epoxy hardeners, adhesives, and plastic modifiers. In the present paper we have studied the interaction between 1-methylimidazole-2-thiol 1 and prenyl bromide (2a), trans-cinnamyl chloride (2b), and butenyl bromide under various conditions for the first time. It has been found that selectivity of the alkylation reactions of compound 1 depends on the reaction conditions (alkylating agent, solvent, and base). Synthesis of individual 1-methyl-2-prenylsulfanylimidazole (3a) (yielding 78–86 %), 1-methyl-2-cinnamylsulfanylimidazole (3b) (yielding 94–97 %), and 2-(3-butenyl)sulfanyl-1-methyl-imidazole (4) (yielding 33–75 %) has been carried out by alkylation of 1-methylimidazole-2-thiol 1 with prenyl bromide 2a, trans-cinnamyl chloride 2b, and butenyl bromide, respectively, in the following systems: i-PrOH–i-PrONa, K2CO3–Me2CO (for 3а), MeOH–MeONa, i-PrOH–i PrONa, K2CO3–Me2CO, K2CO3–MeCN and i-PrOH–i-PrOК (for 3b), MeOH–MeONa, i PrOH–i-PrONa, K2CO3–Me2CO, K2CO3–MeCN, i-PrOH–i-PrOК and КОН–H2O–BTEAC (for 4). The structure of the synthesized compounds 3a,b and 4 has been studied and proved by mass spectrometry (GC–MS), as well as ¹H, ¹³C NMR spectroscopy. General predictable directions for fragmentation of the molecular ions of S-derivatives 3a,b and 4, which are accompanied by elimination of methyl/phenyl and thiol radicals, have been revealed. The evidence that alkylation reactions occur at the sulfur atom is the presence of signals for the –SCH2– protons in the region of 3.12–3.84 ppm in the 1Н NMR spectra of compounds 3a,b and 4. According to the 1Н NMR data, it has been found that alkylation of 1-methylmimidazole-2-thiol 1 at other conditions leads to formation of small quantities of by-products, such as N-alkenyl and S,N-dialkenyl derivatives, due to its thione-thiol tautomerism.

Di- and polyazides. Synthesis, chemical transformations and practical applications

The chemistry of organic di- and polyazides has been extensively developed in recent years. Methods for the synthesis of 1,1- and 1,2-diazides are diverse and include stoichiometric, catalytic, photochemical and electrochemical approaches. These organic compounds are highly reactive and are involved in a wide range of reactions, from thermal transformations to click chemistry. Of particular attention are transformations, in which one azido group undergoes intramolecular cyclization, while another azido group remains intact and can participate in further chemical transformations. Tri- and polyazides are investigated as precursors for the production of high-energy materials and the synthesis of high-molecular-weight compounds. This review addresses the methods for the synthesis of organic compounds containing two or more azido groups and their chemical transformations. Aliphatic, aromatic and heteroaromatic diazides are considered. Specific transformations characteristic of geminal and vicinal diazides, which differ from the reactions of monoazides, are described. Examples of the practical application of di-, tri- and polyazides are highlighted.<br> The bibliography includes 355 references

Electrochemical oxidation of styrene to benzaldehyde by discrimination of spin-paired π electrons.

The oxidation of styrene to benzaldehyde has been a considerable challenge in the electrochemical synthesis of organic compounds because styrene is more easily oxidized to benzoic acid. In this work, MnO2 with an asymmetric electronic configuration is designed to discriminate the spin-paired π electrons of styrene. One of these discriminated π electrons combined with reactive oxygen species (ROS), ˙OH, ˙OOH, etc., produced simultaneously on a MnO2/(Ru0.3Ti0.7)O2/Ti bifunctional anode, to form benzaldehyde via Grob fragmentation, rather than benzoic acid. However, only benzoic acid is obtained from the oxidation of styrene on the anodes MOs/(Ru0.3Ti0.7)O2/Ti, where MOs are other metal oxides with symmetric electronic configurations.

Ca(IO3)2 nanoparticles: fabrication and application as an eco-friendly and recyclable catalyst for the green synthesis of quinoxalines, pyridopyrazines, and 2,3-dicyano pyrazines

In this paper, calcium iodate nanoparticles were first synthesized by the modified reaction of Ca(NO3)2 and KIO3 in an aqueous medium under ultrasonic irradiation. The structure of nanocatalyst was then characterized by FT-IR, FESEM, EDX, XRD, and BET techniques. Afterward, the fabricated Ca(IO3)2 was applied as a nanocatalyst in the facile synthesis of heterocycles including quinoxalines, 5,6-dicyano pyrazines, and pyrido[2,3-b]pyrazines. For this purpose, the feasibility of the reaction in the presence of different catalyst amounts, solvents, and temperatures was first investigated. Next, the target compounds were obtained by the condensation reaction of aryl-1,2-diamines or 2,3-diaminomaleonitrile with 1,2-diketones in the presence of a catalytic amount of Ca(IO3)2 in ethanol or acetic acid solvents at ambient temperature in good to excellent yields. One of the salient advantages of this work is the synthesis of calcium iodate nanoparticles by chemical precipitation method and its application as a heterogeneous nanocatalyst for the first time in the synthesis of organic compounds. The other important benefits of this process are the use of an inexpensive, safe, stable and recyclable catalyst, high product yields, short reaction times, and easy isolation of the product in pure form.

Two faces of TEMPO (2,2,6,6-tetramethylpiperidinyl-1-oxyl) – An antioxidant or a toxin?

2,2,6,6-Tetramethylpiperidine-1-oxyl, commonly known as TEMPO, is one of the compounds called nitroxides that are used in the chemical industry for synthesis of many organic compounds as well as for electrodes in all-organic radical batteries. Additionally, TEMPO is a widely used antioxidant in scientific studies. Technological progress and simultaneous care for the environment leads to resorting to new industrial methods which require the use of compounds that have not been fully tested for their impact on living organisms. Therefore, TEMPO may be an environmental pollutant and its effect on living organisms is not fully understood. The aim of our study was to determine the influence of TEMPO on the physiology, chronological lifespan and wide transcription changes of a eukaryotic model organism, namely the Saccharomyces cerevisiae yeast. For this purpose, we used the BY4741 wild-type and isogenic mutants with a disorder in the response to oxidative stress (sod1Δ, sod2Δ, yap1Δ) and repair of DNA damage (rad52Δ). We showed that supplementation with TEMPO inhibited the cell growth rate of all analyzed strains while simultaneously slowing down the aging of post-mitotic cells in the yeast population. In addition, TEMPO-treated yeast cells manifested a significantly increased level of metabolism in the wild-type and sod2Δ strains. TEMPO also displayed genoprotective effect by reducing the number of DNA double-strand breaks in cells. Here, we are the first to show the widespread effect of TEMPO on yeast. In conclusion, we have shown that, contrary to the commonly accepted notion, TEMPO has also a toxic effect, especially on active mitotic cells. We hypothesize that translation impairment or ribosome biogenesis disorder is likely to be considered secondary effects of TEMPO toxicity related to cell cycle arrest. Therefore, despite the growing interest in the use of this compound in the chemical industry, its toxic effect on the environment, especially biosphere, should be taken into account.