Amine Derivatives Research Articles

Experimental and theoretical investigations of the effect of bis-phenylurea-based aliphatic amine derivative as an efficient green corrosion inhibitor for carbon steel in HCl solution

A novel bis-phenylurea-based aliphatic amine (BPUA) was prepared via a facile synthetic route, and evaluated as a potential green organic corrosion inhibitor for carbon steel in 1.0 M HCl solutions. NMR spectroscopy experiments confirmed the preparation of the targeted structure. The corrosion inhibitory behavior of the prospective green compound was explored experimentally by electrochemical methods and theoretically by DFT-based quantum chemical calculations. Obtained results revealed an outstanding performance of BPUA, with efficiency of 95.1% at the inhibitor concentration of 50 mg L−1 at 25 °C. The novel compound has improved the steel resistivity and noticeably reduced the corrosion rate from 33 to 1.7 mils per year. Furthermore, the adsorption study elucidates that the mechanism of the corrosion inhibition activity obeys Langmuir isotherm with mixed physisorption/chemisorption modes for BPUA derivatives on the steel surface. Calculated Gibb's free energy of the adsorption process ranges from −35 to −37 kJ mol−1.The SEM morphology analysis validates the electrochemical measurements and substantiates the corrosion-inhibiting properties of BPUA. Additionally, the eco-toxicity assessment on human epithelial MCF-10A cells proved the environmental friendliness of the BPUA derivatives. Density functional theory (DFT) calculations correlated the inhibitor's chemical structure with the corresponding inhibitory behavior. Quantum descriptors disclosed the potentiality of BPUA adsorption onto the surface through the heteroatom-based functional groups and aromatic rings.

Synthesis of novel nitrogen‐phosphorus flame retardants and their flameproof to flammable polymers

AbstractTo prepare the efficiently flame retardants (FR) for the highly flammable polymers, the novel nitrogen‐phosphorus based FRs (P‐N FR) (PN‐3, PN‐4, PN‐5, and PN‐6) were prepared via phosphorus halides and amine derivatives with 40‐90 % in yields. The appearances of P‐N FRs are lightly white solid. All P‐N FRs are water‐insoluble and show a melting point above 40 oC. The success of the synthesis was confirmed by NMR analysis. Both 1H and 31P NMR data show clearly the same as the predicted chemical shift signals. The thermal stability behavior of these FRs was studied via TGA analysis. Thermal decomposition occurs in the range of 220‐260oC under N2 gas. The 80% of a mass loss with one step decomposition and 5‐20% of the char residues at 700oC were obtained. The UL‐94 test with self‐extinguishing behavior on ABS and EVA was realized at 20‐25wt% loadings of P‐N FRs. It was observed that the addition of 18‐20 wt% of PN‐5 acquires UL‐94 V‐0 rating for the highly flammable resins (ABS and EVA) whereas to achieve the UL‐94 V‐0 rating, 20‐30 wt% of loadings of PN‐4 and PN‐6 are needed. It was concluded that the structure moieties of P‐N FR affect its FR behaviors.

The γ-Valerolactone (GVL) as Innoxious Reaction Media for the Synthesis of 2-Aryl-2H-Indazoles via C-N and N-N Bond Formation under Cu(I)-Catalyzed Ligand and Base Free Conditions

An efficient method for N-arylation and N-N bond formation has been developed using an innoxious reaction medium, γ-valerolactone (GVL), as both a solvent and a ligand. The strategy involves utilizing CuI as a catalyst under conditions free of external ligands and bases. Various aldehyde and amine derivatives with different functional groups were investigated, resulting in the production of 2-aryl-2H-indazole compounds with yields ranging from 75% to 93%. This study highlights the effectiveness of GVL, a solvent derived from biomass, as a reaction medium and ligand in a multicomponent reaction.

Synthesis of Ferrocenylimidazo[1,2-a]pyridine-3-amines Using Catalyst ZrO(NO3)2.2H2O and their Theoretical Studies

Abstract: In this study, synthesis of ferrocenylimidazo[1,2-a]pyridine-3-amines was reported from the condensation reaction of ferrocenecarboxaldehyde, 2-aminopyridine, and isocyanides using ZrO(NO3)2.2H2O as an efficient, new, and reusable catalyst under reflux conditions in ethanol. The structures of the products were confirmed by IR, 1H NMR, 13C NMR, and elemental analysis. Quantum theoretical calculations for the structure of compounds (4a, 4b, and 4c) were done using the Def2 with the TZVPPD basis set. Geometric parameters were obtained from the optimized structures, and experimental results were analyzed with the calculated data. The structures of the products were proved by IR, 1H NMR, 13C NMR, and elemental analysis. Computations were carried out for the IR spectra data and 1H NMR and 13C NMR chemical shifts of the ferrocenylimidazo[1,2-a]pyridine-3- amine derivatives in the ground state. Ultimately, a great agreement was found between experimental and theoretical results.

N-unsubstituted Imidazoles: Design, Synthesis, and Antimicrobial Evaluation.

All the current antifungal azoles have one substituted nitrogen atom in their imidazole or triazole rings. In this study, eleven imine and amine derivatives of imidazole, in which both nitrogen atoms of the imidazole ring are unsubstituted, were designed and synthesized. Imine derivatives were prepared by condensation of imidazole-4-carboxaldehyde with appropriate amines, and then in the next step, using sodium borohydride, the imines were reduced to amine derivatives. Docking studies reveal unsubstituted nitrogen atom of the imidazole ring coordinated well with the heme molecule of the receptor. In vitro, antimicrobial evaluation was tested on Candida albicans, E. coli, and Staphylococcus aureus. Based on the results of the antimicrobial study, compound 10, which contains 4-chlorobenzyl moiety, proved to be the most potent compound against Candida albicans, and it was more active than the reference drug fluconazole and showed comparable activity to amphotericin B. Compounds 10 and 11 and compounds 8, 10 and 11 showed significant responses against E. coli and Staphylococcus aureus respectively. It is concluded that compound 10 can be acted as a new lead compound to find new azoles antifungal.

Direct amination of benzene with ammonia by flow plasma chemistry.

Amine derivatives, including aniline and allylic amines, can be formed in a single-step process from benzene and an ammonia plasma in a micro-reactor. Different process parameters such as temperature, residence time, and plasma power were evaluated to improve the reaction yield and its selectivity toward aminated products and avoid hydrogenated or oligomerized products. In parallel, simulation studies of the process have been carried out to propose a global mechanism and gain a better understanding of the influence of the different process parameters. The exploration of diverse related alkenes showed that the double bonds, conjugation, and aromatization influenced the amination mechanism. Benzene was the best reactant for amination based on the lifetime of radical intermediates. Under optimized conditions, benzene was aminated in the absence of catalyst with a yield of 3.8% and a selectivity of 49% in various amino compounds.

Green decorated of gold nanoparticles on calcium lignosulfonate modified magnetic nanoparticles mediated by Cydonia oblonga extract: Investigation of its catalytic efficiency and its performance to treat the human esophageal cancer

This report documents an eco-friendly and sustainable protocol towards the in situ synthesized Au NPs adorned over calcium lignosulfonate (CLS) functionalized magnetite NPs, being templated by Cydonia oblonga plant extract (Fe3O4/CLS/Au NPs), followed by the evaluation of its chemical and biological properties. Physicochemical characteristics of the bio-synthesized material was assessed using an array of advanced techniques like FT-IR, SEM, TEM, EDX, elemental mapping, VSM and ICP-OES. The prepared Fe3O4/CLS/Au nanomaterial displayed an excellent catalytic performance in the formylation of amine derivatives to the related N-formyl amines. The prepared Fe3O4/CLS/Au was isolated magnetically from the reaction medium and recycled for 9 times without any significant decrease in catalytic activity. In the medicinal part, the anticancer properties of Fe3O4/CLS/Au against human esophageal cancer cell lines were determined. The IC50 of the Fe3O4/CLS/Au were 327, 228, 318, 289, 238, 208, 347, and 213μg/mL against human esophageal cancer (KYSE-30, KYSE-50, KYSE-70, KYSE-270, SK-GT-4, OE33, ESO26, and FLO-1) cell lines.

Synthesis of Schiff Bases and Secondary Amines with Indane Skeleton; Evaluation of Their Antioxidant, Antibiotic, and Antifungal Activities.

In this study, Schiff bases were synthesized by utilizing the reaction of 4- and 5-aminoindane with substituted benzaldehydes. After the reduction of isolated Schiff bases with NaBH4 , the corresponding secondary amine derivatives were obtained. The structures of all synthesized molecules were confirmed by 1 H-NMR, 13 C-NMR, FT-IR, and ESI-MS. Antioxidant activities of all synthesized molecules were investigated by DPPH method, and IC50 values were calculated. In addition, antibacterial activities of targets were investigated by the well diffusion method, and then MIC99 values were calculated. While only four of the sixteen synthesized molecules showed a high level of antioxidant activity, all of the molecules exhibited biological activity against Gram-positive and Gram-negative bacteria to varying degrees. In addition, all the synthesized molecules showed high antifungal activity. In antioxidant capacity studies, the IC50 values of 2-(((2,3-dihydro-1H-inden-5-yl)amino)methyl)-6-methoxyphenol (4 d) and 2-(((2,3-dihydro-1H-inden-4-yl)amino)methyl)-6-methoxyphenol (7 d) were determined to be 18.1 μg and 35.1 μg, respectively, and these values are much stronger than BHT (butylated hydroxytoluene) and BHA (butylated hydroxyanisole) used as positive controls. The fact that targets have the same core structure with different substituents has revealed a good structure-activity relationship.

Osteogenic induction of asiatic acid derivatives in human periodontal ligament stem cells

Asiatic acid (AA) and asiaticoside, pentacyclic triterpenoid compounds derived from Centella asiatica, are known for their biological effects in promoting type I collagen synthesis and inducing osteogenesis of stem cells. However, their applications in regenerative medicine are limited due to their low potency and poor aqueous solubility. This work aimed to evaluate the osteogenic induction activity of AA derivatives in human periodontal ligament stem cells (hPDLSCs) in vitro. Four compounds were synthesised, namely 501, 502, 503, and 506. AA was used as the control. The 502 exhibited low water solubility, while the 506 compound showed the highest. The cytotoxicity analysis demonstrated that 503 caused significant deterioration in cell viability, while other derivatives showed no harmful effect on hPDLSCs. The dimethyl aminopropyl amine derivative of AA, compound 506, demonstrated a relatively high potency in inducing osteogenic differentiation. An elevated mRNA expression of osteogenic-related genes, BMP2, WNT3A, ALP, OSX and IBSP was observed with 506. Additionally, the expression of BMP-2 protein was enhanced with increasing dose of 506, and the effect was pronounced when the Erk signalling molecule was inhibited. The 506 derivative was proposed for the promotion of osteogenic differentiation in hPDLSCs by upregulating BMP2 via the Erk signalling pathway. The 506 molecule showed promise in bone tissue regeneration.

Bacterial Metabolites and Inflammatory Skin Diseases.

The microbiome and gut-skin axis are popular areas of interest in recent years concerning inflammatory skin diseases. While many bacterial species have been associated with commensalism of both the skin and gastrointestinal tract in certain disease states, less is known about specific bacterial metabolites that regulate host pathways and contribute to inflammation. Some of these metabolites include short chain fatty acids, amine, and tryptophan derivatives, and more that when dysregulated, have deleterious effects on cutaneous disease burden. This review aims to summarize the knowledge of wealth surrounding bacterial metabolites of the skin and gut and their role in immune homeostasis in inflammatory skin diseases such as atopic dermatitis, psoriasis, and hidradenitis suppurativa.

Interrogating the configurational stability of atropisomers.

Atropisomers are molecules whose stereogenicity arises from restricted rotation about a single bond. They are of current importance because of their applications in catalysis, medicine and materials science. The defining feature of atropisomeric molecules is that their stereoisomers are related to one another by bond rotation: as a result, evaluating their configurational stability (i.e., the rate at which their stereoisomers interconvert) is central to any work in this area. Important atropisomeric scaffolds include C-C linked biaryls, such as the ligand BINAP and the drug vancomycin, and C-N linked amine derivatives such as the drug telenzepine. This article focuses on the three most widely used experimental methods that are available to measure the rate of racemization in atropisomers, namely: (i) kinetic analysis of the racemization of an enantioenriched sample, (ii) dynamic HPLC and (iii) variable-temperature NMR. For each technique, an explanation of the theory is set out, followed by a detailed experimental procedure. A discussion is also included of which technique to try when confronted with a new molecular structure whose properties are not yet known. None of the three procedures require complex experimental techniques, and all can be performed by using standard analytical equipment (NMR and HPLC). The time taken to determine a racemization rate depends on which experimental method is required, but for a new compound it is generally possible to measure a racemization rate in <1 d.

Tert‐Butylnitrite Mediated Regioselective C(sp2)−3 Nitration of Substituted 4‐Quinolones and Its Late‐stage Manipulations

AbstractA novel and eco‐friendly technique for the synthesis of C‐3 nitro derivatives of 4‐quinolones via the regioselective C(sp2)−H bond functionalization employing tert‐butyl nitrite as nitrating agent in presence of TEMPO [(2,2,6,6‐tetramethylpiperidin‐1‐yl)oxyl] as an oxidant is unfolded herein. The protocol is scalable as well as high yielding with wide substrate scope and broad functional group tolerance. In‐depth mechanistic investigations revealed that the reaction occurred through a free radical pathway. The nitro derivatives of 4‐quinlones were selectively reduced to corresponding aminated 4‐quinolones. Finally, the photophysical properties of synthesized amine derivatives were also investigated, and some of them showed good fluorescence properties.

A Domino Radical Amidation/Semipinacol Approach to All-Carbon Quaternary Centers Bearing an Aminomethyl Group.

A photoredox-mediated radical amidation ring-expansion sequence that enables the generation of all-carbon quaternary centers bearing a protected aminomethyl substituent is described. The methodology can be applied to both styrene and unactivated alkene substrates generating structurally diverse sp3 -rich amine derivatives in a concise manner.

Solubility in supercritical carbon dioxide of two novel amine derivatives of 2,3-dichloronaphthalene-1,4-dione (dichlone)

Dichlone (2,3-dichloronaphthalene-1,4-dione) is an important antimicrobial agent for agriculture, which effectiveness could be improved by modifying its structure, while the recovery of high-purity synthesized derivatives from a reaction mixture could be accomplished by extracting them with supercritical carbon dioxide. Two new amine derivatives, 2-chloro-3-((4-chlorobenzyl)amino)naphthalene-1,4-dione (dCl-2B-Cl) and 2-chloro-3-((4-chlorophenethyl)amino)naphthalene-1,4-dione (dCl‐3P‐Cl), were synthesized from dichlone, and their solubility in supercritical carbon dioxide was measured afterwards at (313, 323 and 333) K and a pressure range from (8−33) MPa. Experimental solubilities spanned from (10.3·10-6 to 22.1·10-6) mol·mol-1 for dCl-2B-Cl, and from (32.7·10-6 to 131·10-6) mol·mol-1 for dCl‐3P‐Cl. The solubility data of the dichlone family (dichlone, dCl-2B-Cl, dCl‐3P‐Cl, 2‐(benzylamino)‐3‐chloronaphthalene‐1,4‐dione (dCl-2B) and 2-chloro-3-(phenethylamino)naphthalene-1,4-dione (dCl‐3P)) was compared using three models, i.e., the Chrastil equation, the Molecular Connectivity Indices model, and the Statistical Associating Fluid Theory of Variable Range and Mie Potential equation of state, to identify the quantitative structure-property relationship between them. Solubility had an inverse relation with solute size and polarity, but there were some exceptions that could be explained by performing a stereochemical analysis, which showed that steric effects involved in the folding of dCl‐3P and dCl‐3P‐Cl provided them a better geometry for solvation than dCl-2B and dCl-2B-Cl, respectively, making them more soluble. This demonstrates that the solute geometry is an important factor in the solvation process, and it must be represented accurately to develop better predictive models.

Electrocatalytic Access to Azetidines via Intramolecular Allylic Hydroamination: Scrutinizing Key Oxidation Steps through Electrochemical Kinetic Analysis.

Azetidines are prominent structural scaffolds in bioactive molecules, medicinal chemistry, and ligand design for transition metals. However, state-of-the-art methods cannot be applied to intramolecular hydroamination of allylic amine derivatives despite their underlying potential as one of the most prevalent synthetic precursors to azetidines. Herein, we report an electrocatalytic method for intramolecular hydroamination of allylic sulfonamides to access azetidines for the first time. The merger of cobalt catalysis and electricity enables the regioselective generation of key carbocationic intermediates, which could directly undergo intramolecular C-N bond formation. The mechanistic investigations including electrochemical kinetic analysis suggest that either the catalyst regeneration by nucleophilic cyclization or the second electrochemical oxidation to access the carbocationic intermediate is involved in the rate-determining step (RDS) of our electrochemical protocol and highlight the ability of electrochemistry in providing ideal means to mediate catalyst oxidation.

Discovery of 3-(1H-benzo[d]imidazole-2-yl)-1H-pyrazol-4 -amine derivatives as novel and potent syk inhibitors for the treatment of hematological malignancies

Spleen tyrosine kinase (Syk) is an important oncogene and signal transduction mediator that is mainly expressed in hematopoietic cells. Syk plays a key role in the B cell receptor (BCR) signaling pathway. Abnormal activation of Syk is closely related to the occurrence and development of hematological malignancies. Therefore, Syk is a potential target for the treatment of various hematologic cancers. Starting from compound 6(Syk, IC50 = 15.8 μM), we performed fragment-based rational drug design for structural optimization based on the specific solvent-accessible region, hydrophobic region, and ribose region of Syk. This resulted in the discovery of a series of novel 3-(1H-benzo [d]imidazole-2-yl)-1H-pyrazol-4-amine Syk inhibitors, which led to the identification of 19q, a highly potent Syk inhibitor that exhibited excellent inhibitory activity on Syk enzyme (IC50 = 0.52 nM) and showed potency against several other kinases. In addition, compound 19q effectively reduced phosphorylation of downstream PLCγ2 level in Romos cells. And it also exhibited antiproliferative activity in multiple hematological tumour cells. More gratifyingly, 19q showed impressive efficacy at a low dosage (1 mg/kg/day) in the MV4-11 mouse xenograft model without affecting the body weight of the mice. These findings suggest that 19q is a promising new Syk inhibitor for treating blood cancers.

Synthesis of Novel Porphyrin Derivatives and Investigate their Application in Sensitized Solar Cells

Solar energy has significant advantages compared to conventional sources such as coal and natural gas, including no emissions, no need for fuel, and the potential for installation in a wide range of locations with access to sunlight. In this investigation, heterocyclic derivatives were synthesized from several porphyrin derivatives (4,4',4",4"'-(porphyrin-5,10,15,20-tetrayl) tetra benzoic acid) compound (3), obtained by reaction Pyrrole with 4-formyl benzoic acid. Subsequently, porphyrin derivative-component amides 5a, 5b, and 5c were produced by reacting compound (3) with amine derivatives at a 1:4 molar ratio. These derivatives exhibited varying sensitivities for utilization in solar cells, with compound 5a displaying the highest power conversion efficiency (PCE) at 1.37%, as determined by measuring the short circuit current (Jsc), open-circuit voltage (Voc), and fill factor (FF) (Jsc = 2.24 mA cm-2, Voc = 0.80 mV, FF = 76.5%). Meanwhile, compound 5c exhibited the lowest PCE at 0.94% (Jsc = 1.55 mA cm-2, Voc = 0.750 mV, FF = 76.4%).

Mild and selective hydrogen-deuterium exchange for aromatic hydrogen of amines.

The direct electrophilic deuteration of the aromatic moiety in aromatic and aralkyl amines is reported. The acid-catalyzed deuteration is facilitated by deuterated trifluoromethanesulfonic acid, [D]triflic acid, CF3 SO3 D, TfOD, which acts as both the reaction solvent and the source of the deuterium label. The mild conditions enable room temperature hydrogen/deuterium exchange for most of the para-substituted aromatic amine derivatives studied. In addition, short reaction times and a high degree of aromatic deuteration are achieved and isolation of the product is simple. The optical activity of the chiral aralkyl amines studied was preserved.

Synthesis and Characterization of Inorganic-Organic Derivatives of Layered Perovskite-like Niobate HSr2Nb3O10 with n-Amines and n-Alcohols.

A protonated and hydrated Dion-Jacobson-phase HSr2Nb3O10∙yH2O was used to prepare two series of inorganic-organic derivatives containing non-covalently intercalated n-alkylamines and covalently grafted n-alkoxy groups of different lengths, as they are promising hybrid materials for photocatalytic applications. Preparation of the derivatives was carried out both under the conditions of standard laboratory synthesis and by solvothermal methods. For all the hybrid compounds synthesized structure, quantitative composition, a type of bonding between inorganic and organic parts as well as light absorption range were discussed using powder XRD, Raman, IR and NMR spectroscopy, TG, elemental CHN analysis, and DRS. It was shown that the inorganic-organic samples obtained contain approximately one interlayer organic molecule or group per proton of the initial niobate, as well as some amount of intercalated water. In addition, the thermal stability of the hybrid compounds strongly depends on the nature of the organic component anchoring to the niobate matrix. Although non-covalent amine derivatives are stable only at low temperatures, covalent alkoxy ones can withstand heat up to 250 °C without perceptible decomposition. The fundamental absorption edge of both the initial niobate and the products of its organic modification lies in the near-ultraviolet region (370-385 nm).

Three amine derivative/graphene oxide van der Waals heterostructures for the photocatalytic detoxification of As(III)

Although van der Waals heterostructures (vdWHs) have suggested the considerable advantages in engineering photoelectronic properties, it remains the limited understanding for the roles of typical nitrogen configurations in vdWHs. Herein, pyrrolic N, pyridinic N, and graphitic N, are introduced into the vdWHs via assembling indole, quinoline, and indolizine with graphene oxide (GO). Pyrrolic N prefers to adhere to the hydroxyls on GO surface, pyridinic N is apt to be immobilized by the carboxyls, and graphitic N shows poor affinitive selectivity. Both pyrrolic and pyridinic N introduce new π→π* orbitals into the resulted vdWHs, while, graphitic N leads to an obvious decay of n→π* transition. All amine derivatives in the vdWHs inject electrons into the conduction band of GO to provide n-type doping, which leads to decreased bandgaps. The decreasing conductivities are observed in all vdWHs, which is temporarily ascribed to the unfavorable electronic correlations at the van der Waals interfaces. By contrast, pyrrolic N contributes more electrons to GO, which enables In-GO to exhibit stronger photocurrent response (almost 7 times as much as the other heterostructures and GO) and higher photocatalytic activity for oxidating As(III) (6.8, 3.6, and 2.0 times than Qu-GO, GO and Iz-GO, respectively).