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We have developed a short and highly efficient microwave-enhanced protocol for the synthesis of new Schiff bases, (E)-N-[(2-arylimidazo[1,2-a]pyridine-3-yl)methylidene]pyridin-2-amines, by the condensa-tion of 2-arylimidazo[1,2-a]pyridine-3-carbaldehydes with 2-aminopyridine in polyethylene glycol-400 as a green reaction medium in the presence of a catalytic amount of acetic acid. The essential features of this protocol are enhanced reaction rate, more eco-friendly reaction conditions, high yields, and green aspects such as avoiding toxic catalysts and hazardous organic solvents and reuse of the reaction medium. [ABSTRACT FROM AUTHOR]

In this work, by utilizing 6 mol% of 1,3‐bis(carboxymethyl)imidazolium chloride [BCMIM][Cl] ionic liquid as a catalyst, a highly effective diastereoselective one‐pot multicomponent Mannich reaction has been established. The three components, namely, cyclohexanone, substituted aromatic aldehydes, and substituted aromatic amines, underwent the Mannich reaction efficiently under the solvent‐free condition at room temperature in the presence of 6 mol% [BCMIM][Cl] catalyst to afford the desired β‐amino ketones. Excellent diastereoselectivity, rapid reaction times, high yields, and no purification by column chromatography are the key characteristics of this process. All synthesized derivatives were thoroughly characterized and confirmed using 1H NMR, 13C NMR, and Fourier‐transform infrared spectral methods. Moreover, the catalytic activity of the [BCMIM][Cl] ionic liquid catalyst was maintained after being reprocessed and used three times. [ABSTRACT FROM AUTHOR]

Background: Azo dyes are among the most widely used dyes in the textile industry, releasing a series of carcinogenic aromatic amines that can be absorbed through the skin. Objective: This work aims to show that 22 azo dye amines in a textile matrix can be quantified using a GC-MS method. Methods: Based on the notion of total error and b-content, c-confidence tolerance intervals (b, c-CCTI), a chemometric approach known as the "uncertainty profile" has been used to completely validate a GC-MS method for the simultaneous assay of 22 azo amines in fabrics. According to International Organization for Standardization (ISO) in ISO 17025 guidelines, analytical validation and measurement uncertainty estimates have evolved to be two main principles for ensuring the accuracy of analytical results and controlling the risk associated with their use. Results: The calculated tolerance intervals allowed for the determination of the uncertainty limits at each concentration level. These limits when compared to the acceptable limits show that a significant portion of the expected outcomes is in conformity. Additionally, the relative expanded uncertainty values, calculated with a proportion of 66.7% and a 10% risk, do not exceed 27.7, 12.2, and 10.9% for concentration levels 1, 15, and 30 mg/L, respectively. Conclusion: The capability and flexibility of the b-content, c-confidence intervals have been established through the use of this innovative approach to carrying out qualimetry of the GC-MS method depending on the behavior, required conformity proportion, and acceptable tolerance limits of each amine. Highlights: An efficient GC-MS technique for the simultaneous determination of 22 azo amines in a textile matrix has been developed. Analytical validation using a new strategy based on the uncertainty concept is reported, uncertainty associated to measurement results is estimated, and the applicability of our approach to the GC-MS method is investigated. [ABSTRACT FROM AUTHOR]

The catalyst Y(NO3)3, 6H2O exhibited remarkable activity in the aza-Michael addition of various aromatic and aliphatic amines with acrylonitrile at ambient temperature in a protic solvent. The method is selective for the monocyanoethylation of primary aromatic amines, aliphatic secondary amines, and sterically hindered aliphatic amines. Phenols and active methylene compounds do not undergo cyanoethylation. Thiophenol, in the presence of yttrium nitrate, promotes the polymerization of acrylonitrile. The water solubility and high catalyst stability make the process of removing the catalyst from the product easy. Direct aqueous workup of the reaction mixture could lead to the isolation of cyanoethylation products up to 99.9% purity. Selective mono-cyanoethylation at the primary aromatic amine, especially electron-rich aromatic amines Excellent regio-selectivity in the presence of Carbon and Oxygen nucleophiles The reported condition could be used to polymerize acrylonitrile in the presence of thiophenol. Reaction is facile for electron-rich aromatic amine. Highly sensitive to the steric effect at the nitrogen center [ABSTRACT FROM AUTHOR]

The study of azo dyes degradation products and their harmfulness is an important topic because their diffusion in the environment is still a serious problem. We investigated the reduction by pig liver microsomal fraction of four bis‐azo dyes, Acid Red 73, Acid Red 150, Direct Red 24, and Direct Red 28, in anaerobic condition. These complex molecules, different for position/nature of substituent groups and for the group interposed between the two azo bonds, allowed to investigate the correlation between substrate molecular structure and action of a subcellular fraction representative of the xenobiotic degradation by a living organism and the consequent possible appearance of harmful reaction products. Dyes were first carefully purified to eliminate interferences in the enzymatic assays. The reduction products were identified by gas chromatography/mass spectrometry. Acid Red 73 and Acid Red 150 were markedly reduced with production of harmful aromatic amines, while Direct Red 24 and Direct Red 28 were neither reduced to their synthesis amines nor to other amines. These results suggest that azo dyes with a benzidine derivative group are not degraded by microsomal fraction and therefore molecules with a similar structure could be classified with a lower risk index not producing any harmful catabolic product. [ABSTRACT FROM AUTHOR]

An efficient photoredox-catalyzed three-component coupling reaction of aryl amine, glyoxalate and alkyltrifluoroborates has been reported. A variety of N-arylated amino esters were constructed rapidly using an organic photocatalyst under mild conditions. Broad substrate scope and good functional group tolerance are the key features of this strategy. [ABSTRACT FROM AUTHOR]

Electrocatalytic C − N bond formation from inorganic nitrogen wastes is an emerging sustainable method for synthesizing organic amines but is limited in reaction scope. Integrating heterogeneous and homogeneous catalysis for one-pot reactions to construct C − N bonds is highly desirable. Herein, we report an aqueous pulsed electrochemistry-mediated transformation of nitrite and arylboronic acids to arylamines with high yields. The overall process involves nitrite electroreduction to ammonia over a Cu nanocoral cathode and subsequent coupling of NH3 with arylboronic acids catalyzed by in situ dissolved Cu(II) under a switched anodic potential. This pulsed protocol also promotes the migration of nucleophilic ArB(OH)3− and causes the consumption of OH− near the cathode surface, accelerating C − N formation and suppressing phenol byproducts. Cu(II) can be recycled via facile electroplating. The wide substrate scope, ready synthesis of 15N-labelled arylamines, and methodological expansion to cycloaddition and Click reactions highlight the great promise. Electrocatalytic C − N bond formation from inorganic nitrogen wastes is desirable. Here, a pulsed electrochemical method is reported to promote one-pot cascade C − N bond forming reaction between nitrite and arylboronic acids with water into arylamines. [ABSTRACT FROM AUTHOR]

In this study, we investigated the gas-sensing mechanism in bottom-gate organic field-effect transistors (OFETs) using poly(triarylamine) (PTAA). A comparison of different device architectures revealed that the top-contact structure exhibited superior gas-sensing performance in terms of field-effect mobility and sensitivity. The thickness of the active layer played a critical role in enhancing these parameters in the top-contact structure. Moreover, the distance and pathway for charge carriers to reach the active channel were found to significantly influence the gas response. Additionally, the surface treatment of the SiO2 dielectric with hydrophobic self-assembled mono-layers led to further improvement in the performance of the OFETs and gas sensors by effectively passivating the silanol groups. Under optimal conditions, our PTAA-based gas sensors achieved an exceptionally high response (>200%/ppm) towards NO2. These findings highlight the importance of device and interface engineering for optimizing gas-sensing properties in amorphous polymer semiconductors, offering valuable insights for the design of advanced gas sensors. [ABSTRACT FROM AUTHOR]

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Surface engineering is a promising strategy to improve the catalytic activities of heterogeneous catalysts. Nevertheless, few studies have been devoted to investigate the catalytic behavior differences of the multiple metal active sites triggered by the surface imperfections on catalysis. Herein, oxygen vacancies induced Fe2O3 catalyst are demonstrated with different Fe sites around one oxygen vacancy and exhibited significant catalytic performance for the carbonylation of various aryl halides and amines/alcohols with CO. The developed catalytic system displays excellent activity, selectivity, and reusability for the synthesis of carbonylated chemicals, including drugs and chiral molecules, via aminocarbonylation and alkoxycarbonylation. Combined characterizations disclose the formation of oxygen vacancies. Control experiments and density functional theory calculations demonstrate the selective combination of the three Fe sites is vital to improve the catalytic performance by catalyzing the elemental steps of PhI activation, CO insertion and C-N/C-O coupling respectively, endowing combinatorial sites catalyst for multistep reactions. Surface engineering of Fe sites was used to improve the carbonylation reaction of aryl halides and amines/alcohols with CO. The elementary steps of phenyl iodide activation, CO insertion and C-N/C-O coupling were catalyzed respectively, leading to improved catalytic activity. [ABSTRACT FROM AUTHOR]

Globally, bladder cancer has been identified as one of the most frequent occupational cancers, but our understanding of occupational bladder cancer risk in Iran is less advanced. This study aimed to assess the risk of bladder cancer in relation to occupation in Iran. We used the IROPICAN case‐control study data including 717 incident cases and 3477 controls. We assessed the risk of bladder cancer in relation to ever working in major groups of the International Standard Classification of Occupations (ISCO‐68) while controlling for cigarette smoking, opium consumption. Logistic regression models were used to estimate odds ratios (ORs) and 95% confidence intervals (CI). In men, decreased ORs for bladder cancer were observed in administrative and managerial workers (OR 0.4; CI: 0.2, 0.9), and clerks (OR 0.6; CI: 0.4, 0.9). Elevated ORs were observed in metal processors (OR 5.4; CI: 1.3, 23.4), and workers in occupations with likely exposure to aromatic amines (OR 2.2; CI: 1.2, 4.0). There was no evidence of interactions between working in aromatic amines‐exposed occupations and tobacco smoking or opium use. Elevated risk of bladder cancer in men in metal processors and workers likely exposed to aromatic amines aligns with associations observed outside Iran. Other previously confirmed associations between high‐risk occupations and bladder cancer were not observed, possibly due to small numbers or lack of details on exposure. Future epidemiological studies in Iran would benefit from the development of exposure assessment tools such as job exposure matrices, generally applicable for retrospective exposure assessment in epidemiological studies. [ABSTRACT FROM AUTHOR]

We herein describe the preparation, assembly, recognition characteristics, and biocompatibility of novel covalent basket cage CBC‐11, composed of four molecular baskets linked to four trivalent aromatic amines through amide groups. The cage is tetrahedral in shape and similar in size to small proteins (Mw=8637 g/mol) with a spacious nonpolar interior for accommodating multiple guests. While 24 carboxylates at the outer surface of CBC‐11 render it soluble in aqueous phosphate buffer (PBS) at pH=7.0, the amphiphilic nature prompts its assembly into nanoparticles (d=250 nm, DLS). Cryo‐TEM examination of nanoparticles revealed their crystalline nature with wafer‐like shapes and hexagonally arranged cages. Nanoparticulate CBC‐11 traps anticancer drugs irinotecan and doxorubicin, with each cage binding up to four drug molecules in a non‐cooperative manner. The inclusion complexation resulted in nanoparticles growing in size and precipitating. In media containing mammalian cells (HCT 116, human colon carcinoma), the IC50 value of CBC‐11 was above 100 μM. While this work presents the first example of a large covalent organic cage operating in water at the physiological pH and forming crystalline nanoparticles, it also demonstrates its biocompatibility and potential to act as a polyvalent binder of drugs for their sequestration or delivery. [ABSTRACT FROM AUTHOR]

Acid catalyzed multicomponent reaction (MCR) for the synthesis of N‐benzhydryl amide derivatives from aldehydes, N,N‐disubstituted arylamines and nitriles is reported. The reaction is compatible with electronically differentiating aryl/heteroaryl aldehydes/acetals, different nucleophiles (cyclic and acyclic N,N‐disubstituted arylamines,β‐naphthols, 1,3 dicarbonyl, 1,3,5‐trimethoxy benzene), alkyl nitriles, aryl/heteroaryl nitriles in catalytic TFA/TfOH through tandem Ritter reaction. The one‐pot MCR with broad substrate scope generated a wide variety of sterically hindered N‐substituted amides and is successfully applied for the synthesis of isoindolinone. [ABSTRACT FROM AUTHOR]

In this work, we present a rapid, metal‐free and efficient method for thiocyanation of aromatic amines under microwave irradiation for the synthesis of aryl thiocyanates using inexpensive and nontoxic NH4SCN as thiocyanato source and K2S2O8 as an oxidant. This protocol tolerates a wide range of substituted anilines to provide the corresponding thiocyanated products in good to excellent yields. The features of this strategy include a broad substrate scope, high functional group tolerance, mild reaction conditions, and short reaction time. [ABSTRACT FROM AUTHOR]

Understanding of metabolic processes is a key factor to evaluate biological effects of carcinogen and mutagens. Applicability of fused-grid Template* systems of CYP enzymes (Drug Metab Pharmacokinet 2019, 2020, 2021, and 2022) was tested for three phenomena. (1) Possible causal relationships between CYP-mediated metabolisms of β-naphthoflavone and 3-methylcholanthrene and the high inducibility of CYP enzymes were examined. Selective involvement of non-constitutive CYP1A1, but not constitutive CYP1A2, was suggested on the oxidative metabolisms of efficient inducers, β-naphthoflavone and 3-methylcholanthrene. These results supported the view of the causal link of their high inducibility with their inefficient metabolisms due to the lack of CYP1A1 in livers at early periods after the administration of both inducers. (2) Clear differences exist between human and rodent CYP1A1 enzymes on their catalyses with heterocyclic amines, dioxins and polyaromatic hydrocarbons (PAHs). Reciprocal comparison of simulation results with experimental data suggested the rodent specific site and distinct sitting-preferences of ligands on Template for human and rodent CYP1A1 enzymes. (3) Enhancement of metabolic activation and co-mutagenicity have been known as phenomena associated with Salmonella mutagenesis assay. Both the phenomena were examined on CYP-Templates in ways of simultaneous bi-molecule bindings of distinct ligands as trigger and pro-metabolized molecules. α-Naphthoflavone and norharman served consistently as trigger-molecules to support the oxidations of PAHs and arylamines sitting simultaneously as pro-metabolized molecules on Templates of CYP1A1, CYP1A2 and CYP3A4. These CYP-Template simulation systems with deciphering capabilities are promising tools to understand the mechanism basis of metabolic activations and to support confident judgements in safety assessments. [ABSTRACT FROM AUTHOR]

A scalable and operationally simple on water seleno‐mediated reduction of nitroarenes to the respective aryl amines with NaBH4 is described. The reaction proceeds under transition metal‐free conditions and is promoted by the formation of Na2Se, which is the effective reducing agent involved in the mechanism. This mechanistic information enabled the development of a mild NaBH4‐free protocol for the selective reduction of nitro derivatives bearing labile moieties, including nitrocarbonyl compounds. The selenium‐containing aqueous phase can be successfully reused up to four reduction cycles, thus further improving the efficiency of the protocol disclosed. [ABSTRACT FROM AUTHOR]

Chiral amines are broadly used compounds in pharmaceutical industry and organic synthesis, and reductive amination reactions have been the most appreciated methods for their syntheses. However, one‐step transfer hydrogenative direct asymmetric reductive amination (THDARA) that could expand the scope, simplify the operation and eliminate the use of additives has been challenging. In this work, based on the Xiao's racemic transfer hydrogenative reductive amination in 2010 and our recent work in novel chiral pyridine ligands, chiral half‐sandwich iridium catalysts were rationally designed and synthesized. Using the optimized catalyst and azeotropic mixture of formic acid and triethylamine as the hydrogen source, a broad range of α‐chiral (hetero)aryl amines, including various polar functional groups and heterocycles, were prepared in generally high yield and enantioselectivity under mild and operationally simple conditions. Density functional theory (DFT) calculation of the catalytically active Ir−H species and the key hydride transfer step supported the chiral pyridine‐induced stereospecific generation of the iridium center, and the enantioselection by taming the highly flexible key transition structure with multiple attractive non‐covalent interactions. This work introduced a type of effective chiral catalysts for simplified approach to medicinally important chiral amines, as well as a rare example of robust enantioselective transition‐metal catalysis. [ABSTRACT FROM AUTHOR]

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, CF3SO3D, 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. [ABSTRACT FROM AUTHOR]

In the current study, the impacts of using cumin (0.5% and 1%, w/w) in beef meatballs on heterocyclic aromatic amines (HAAs) formation and some quality characteristics when cooked at 150 and 250 °C were investigated. It was found that using of cumin at different ratios in beef meatballs showed a significant (p < 0.01) effect on pH, thiobarbituric acid reactive (TBARS) value, and total HAA. The cooking process significantly (p < 0.01) affected the meatballs' water content, pH, and TBARS values, while the cooking loss and total HAA content of meatballs were significantly (p < 0.01) affected by cooking temperature. It was found that the cumin usage rate in meatballs increased the pH value, while it was found to decrease the TBARS value. As expected, the cooking process was associated with a reduction in water, while it was found to result in an increase in the pH and TBARS values. On the other hand, both cooking temperature and cumin addition to meatballs led to an increase in their total HAA content. Diverse samples exhibited detectable levels of IQx, MeIQx, MeIQ, and PhIP compounds. The presence of MeIQx compound was found in all samples, except for the control group cooked at 150 °C. Additionally, the use of 0.5% and 1% cumin in meatballs cooked at temperature of 250 °C had an inhibitory effect on MeIQx compound. Our results revealed that the incorporation of cumin in the meatballs resulted in an increase in the total HAA content, likely due to its prooxidant effect. However, it was found that the use of cumin at certain rates could reduce the formation of MeIQx compound with an antioxidant effect. However, in this study found that even if 100 g of meatballs with the highest concentration of total HAA were consumed, the maximum HAA exposure limit value (0–15 µg/day) was not exceeded. [ABSTRACT FROM AUTHOR]

Natural rubber (NR) powder wastes contribute to the pollution of the environment and pose a risk to human health. Therefore, Escherichia coli AY1 and Aspergillus oryzae were used to degrade NR in the present investigation. The biodegradation was further confirmed using E. coli AY1 and A. oryzae's ability to create biofilm, which grew on the surface of the NR. Additionally, the biodegraded NR was examined by scanning electron microscopy (SEM), attenuated total reflection–Fourier transform infrared (ATR–FTIR) spectroscopy, and gas chromatography–mass spectrometry (GC–MS). The highest weight loss (69%) of NR was detected (p < 0.05) after 210 d of incubation with the mixed microbial culture (E. coli AY1 + A. oryzae). In the SEM, the surface of the control treatment appeared uniform and normal, whereas the surface of the microbial treatment displayed an irregular shape, with apparent particle deformation and surface erosion. After biodegradation by E. coli AY1 and A. oryzae, the particle size range of the untreated NR dropped from (5.367–9.623 µm) to (2.55–6.549 µm). After treating NR with E. coli AY1 and A. oryzae, new bands appeared in the ATR–FTIR technique; others shifted down in the range of 3910–450 cm−1, suggesting the existence of active groups belonging to alcohol, secondary amine, aromatic amine, conjugated anhydride, aldehyde, alkene, and halo compounds. On the other hand, the GC–MS profile reports a significant decline (p < 0.05) in the amount of hydrocarbons while simultaneously reporting a significant increase (p < 0.05) in the proportion of oxygenated, sulfurous, and nitrogenous compounds. These active groups are attributed to the antioxidant and antibacterial properties of biodegraded NR by a mixture of E. coli AY1 and A. oryzae, which rose 9-fold (p < 0.05) compared to untreated NR. Through the use of this research, we will be able to transform NR waste into a valuable product that possesses both antioxidant and antibacterial properties. [ABSTRACT FROM AUTHOR]

It should be mentioned that so far electrocarboxylation has been mainly explored for the carboxylation of olefins and imines, and only a few reports have been published on direct electrocatalytic C(sp SP 3 sp )-H bond carboxylation reactions. In previous studies, transition-metal or transition-metal-free methodologies proceeded through C(sp SP 3 sp )-H bond carboxylation reactions via enolate chemistry to trap a CO SB 2 sb molecule in order to give carboxylation products. Recent Advances on the Carboxylations of C(sp3)-H Bonds Using CO2 as the Carbon Source Keywords: carbon dioxide; transition-metal; transition-metal-free; thermochemical strategy; visible-light-induced photocatalysis; electrocatalysis; reductive C-H carboxylations; carboxylic acids EN carbon dioxide transition-metal transition-metal-free thermochemical strategy visible-light-induced photocatalysis electrocatalysis reductive C-H carboxylations carboxylic acids 1327 1342 16 07/11/23 20230725 NES 230725 Graph 1 Introduction The carboxylic acid unit is omnipresent in bioactive drug molecules, pharmaceuticals, natural products, and agrochemicals. [Extracted from the article]

A facile multicomponent, catalyst‐free oxazolidinone synthesis from primary aliphatic or aromatic amines, dibromoethane (DBE), and the usage of either cesium carbonate or cesium hydrogencarbonate as the simultaneous base and C1 source is reported. The applicability of this technically simple reaction was demonstrated by a broad scope with generally high yields, enabling concise late‐stage functionalization of amino groups into N‐substituted oxazolidinones. The proposed operating reaction mechanism consists of a first‐step nucleophilic substitution reaction between DBE and the primary amine, followed by the formation of a carbamate or carbonate intermediate and subsequent cyclization. Additional versatility of the herein‐developed protocol has been showcased in a medicinal chemistry approach by the generation of an oxazolidinone‐modified dipeptidyl peptidase 8 (DPP8) inhibitor. [ABSTRACT FROM AUTHOR]

A one‐pot synthesis of 2,3,4‐unprotected β‐N‐glycopyranosides from glycals and amines with exclusive β‐stereoselectivity under room temperature conditions is reported. This method was achieved via palladium‐catalyzed Tsuji‐Trost amination followed by dihydroxylation directly, tolerating anilines, heterocyclic aromatic amines, and N,O‐dimethylhydroxylamine, especially the reaction of primary amines and glycals has not been reported before. Furthermore, the protocol was applied to modify clinical drugs (prazosin, imiquimod) and construct the analogue of the natural product amphimedoside A. [ABSTRACT FROM AUTHOR]

A highly efficient, one-pot, three-component Strecker reaction for the synthesis of α-aminonitriles from carbonyl compounds, amines, and potassium hexacyanoferrate (II) (K4[Fe(CN)6]) in the presence of a catalytic amount of humic acid catalyst in water at room temperature has been developed. Advantages of this methodology are use of inexpensive, commercially available, environmentally friendly and reusable organocatalyst, environmentally benign and inexpensive cyanide source, simple experimental and work-up procedure, high yields, room temperature reaction, water as a green solvent and scaled-up synthesis. Environmentally friendly, commercially available, inexpensive and reusable catalyst Environmentally friendly and inexpensive cyanide source High yields Simple operations and mild conditions Water as a green solvent Green synthesis [ABSTRACT FROM AUTHOR]

Some aromatic amines (AA) have been classified as carcinogens to humans. After entering the body, mainly through tobacco smoke, they can be detected in urine. Thus, their trace analysis as biomarkers in biofluids is of high relevance and can be achieved with gas chromatography (GC–MS), usually after derivatization. This study compares three gas chromatographic methods for the analysis of ten iodinated derivatives of AA: GC–MS in single-ion monitoring (SIM) mode with (1) electron ionization (GC-EI-MS) and (2) negative chemical ionization (GC-NCI-MS), and (3) GC-EI-MS/MS in multiple reaction monitoring (MRM) mode using electron ionization. All methods and most analytes showed good coefficients of determination (R2 > 0.99) for broad linear ranges covering three to five orders of magnitude in the picogram-per-liter to nanogram-per-liter range, with one and two exceptions for (1) and (2) respectively. Excellent limits of detection (LODs) of 9–50, 3.0–7.3, and 0.9–3.9 pg/L were observed for (1), (2), and (3) respectively, and good precision was achieved (intra-day repeatability < 15% and inter-day repeatability < 20% for most techniques and concentration levels). On average, recoveries between 80 and 104% were observed for all techniques. Urine samples of smokers and non-smokers were successfully analyzed, and p-toluidine and 2-chloroaniline could be found at significantly (α = 0.05) higher concentrations among smokers. [ABSTRACT FROM AUTHOR]

The 1,4‐conjugated addition of nitrogen centered nucleophiles to electron‐deficient alkenes, historically called the aza‐Michael addition, is one of the most significant and widely used reactions in modern synthetic organic chemistry. In the last decade, great progress has been made in this field namely in the development of various catalytic systems. Fundamental advances involve the use of transition metal catalysts, organocatalysts, enzymes, ionic liquids, Brønsted and Lewis acids and bases. This Review aims to critically analyze the results of research into the reactions of aliphatic and aromatic amines with Michael acceptors. [ABSTRACT FROM AUTHOR]

An efficient protocol for the C−N cross‐coupling of aryl chlorides with (hetero)aryl‐ and alkyl amines under nickel catalysis has been developed. The main advantage of the protocol is the use of a self‐activated Ni/NHC catalytic system generated in situ from readily available bench‐stable air‐tolerant precursors: NiCl2Py2, IPr ⋅ HCl, and sodium tert‐butoxide. A mass spectrometry mechanistic study of the reaction system revealed the dynamics of competitive processes of Ni/NHC active species formation and degradation involving NHC reductive elimination reactions and tert‐butoxide base. Optimization of the NiCl2Py2/IPr ⋅ HCl/tBuONa ratio and the reaction temperature allowed efficient catalysis to be achieved. The developed simple protocol represents an alternative for methods relying on the use of air‐sensitive and unstable Ni(cod)2 or expensive well‐defined Ni/NHC precatalysts. [ABSTRACT FROM AUTHOR]

The production of N,N-dialkyl arylamines is relevant for a range of high-value materials such as pharmaceuticals, agrochemicals and organic materials. In general, these molecules are assembled via multiple pre-functionalization steps of the aromatic compound and a subsequent cross-coupling with the arylamine under harsh conditions. In this manuscript, we develop a more sustainable and efficient method for the direct C–H amination of arenes and alkylamines using Ru(bipy)32+ entrapped in the supercages of a faujasite support (CBV-100). This creates a heterogeneous photocatalyst that can be used under visible light irradiation. Furthermore, the mesomeric and/or inductive effects of the substituent groups on the arene coupling partner are thoroughly investigated using Hammett plots, leading to a rationally guided solvent selection (HFIP or CH3CN). Using reduced reaction temperatures (<0 °C) drastically improves the product yield, while suppressing the generation of side products. [ABSTRACT FROM AUTHOR]

We have developed a novel visible‐light‐catalyzed bioconjugation reaction, PhotoCLIC, that enables chemoselective attachment of diverse aromatic amine reagents onto a site‐specifically installed 5‐hydroxytryptophan residue (5HTP) on full‐length proteins of varied complexity. The reaction uses catalytic amounts of methylene blue and blue/red light‐emitting diodes (455/650 nm) for rapid site‐specific protein bioconjugation. Characterization of the PhotoCLIC product reveals a unique structure formed likely through a singlet oxygen‐dependent modification of 5HTP. PhotoCLIC has a wide substrate scope and its compatibility with strain‐promoted azide‐alkyne click reaction, enables site‐specific dual‐labeling of a target protein. [ABSTRACT FROM AUTHOR]

We have developed an efficient modular asymmetric synthesis of azahelicenes through an organocatalyzed asymmetric multicomponent reaction from readily available polycyclic aromatic amines, aldehydes, and (di)enamides, by employing a central‐to‐helical chirality conversion strategy. A series of aza[5]‐ and aza[4]helicenes bearing various substituents were readily afforded through this one‐pot sequential enantioselective Povarov reaction/oxidative aromatization process, with good yields and high enantioselectivities. The fruitful and diverse derivatizations of the chiral azahelicene products demonstrated the potential of this method, and a preliminary application of the azahelicene derivative as a chiral organocatalyst was showcased. The photophysical and chiroptical properties of these azahelicenes, particularly the acid/base‐triggered switching of these properties, were also well studied, which may find potential applications in the development of novel organic optoelectronic materials. [ABSTRACT FROM AUTHOR]

A method was developed for the synthesis of previously unknown triamides of fumaropimaric acid by the reaction of anilide and 1-(piperidin-1-ylcarbonyl) derivative of fumaropimaric acid with aromatic and heterocyclic amines [4-toluidine, 4-pentylaniline, 4-biphenylamine, 4-methoxy-, ethoxy-, phenoxy-, bromoaniline, 2-picolylamine, 2-(aminomethyl)furan, 2-(aminomethyl)thiophene] under the action of propanephosphonic acid anhydride. [ABSTRACT FROM AUTHOR]

The thermal decomposition path of synthetically and pharmacologically useful hybrid materials was analyzed in inert and oxidizing conditions for the first time and presented in this article. All the imidazoline/dimethyl succinate hybrids (1–5) were studied using the simultaneous thermogravimetry (TG) coupled with Fourier transform infrared spectroscopy (FTIR) and quadrupole mass spectrometry (QMS). It was found that the tested compounds were thermally stable up to 200–208 °C (inert conditions) and up to 191–197 °C (oxidizing conditions). In both furnace atmospheres, their decomposition paths were multi-step processes. At least two major stages (inert conditions) and three major stages (oxidizing conditions) of their decomposition were observed. The first decomposition stage occurred between T5% and 230–237 °C. It was connected with the breaking of one ester bond. This led to the emission of one methanol molecule and the formation of radicals capable of further radical reactions in both used atmospheres. At the second decomposition stage (Tmax2) between 230–237 °C and 370 °C (inert conditions), or at about 360 °C (oxidizing conditions), the cleavage of the second ester bond and N-N and C-C bonds led to the emission of CH3OH, HCN, N2, and CO2 and other radical fragments that reacted with each other to form clusters and large clusters. Heating the tested compounds to a temperature of about 490 °C resulted in the emission of NH3, HCN, HNCO, aromatic amines, carbonyl fragments, and the residue (Tmax2a) in both atmospheres. In oxidizing conditions, the oxidation of the formed residues (Tmax3) was related to the production of CO2, CO, and H2O. These studies confirmed the same radical decomposition mechanism of the tested compounds both in inert and oxidizing conditions. The antitumor activities and toxicities to normal cells of the imidazoline/dimethyl succinate hybrids were also evaluated. As a result, the two hybrid materials (3 and 5) proved to be the most selective in biological studies, and therefore, they should be utilized in further, more extended in vivo investigations. [ABSTRACT FROM AUTHOR]

6,6-Dimethyl-5,6-dihydrobenzo[f]pyrrolo[2,1-a]isoquinoline-8,9-dione and its 1-(morpholine-4-carbonyl)-substituted analog reacted with ammonia, morpholine, aniline, and naphthalen-1-amine via opening of the dioxopyrrole ring to produce enamino keto amides. The reaction conditions depended on the nucleophile nature. Ammonia and morpholine readily reacted at 20°C, whereas the reaction with aromatic amines required heating in boiling glacial acetic acid. [ABSTRACT FROM AUTHOR]

Seven novel syringaldehyde α-aminophosphonate derivatives (1–7) were synthesized based on syringaldehyde together with different aryl amines and diethyl phosphite in a one-pot, solvent free, and catalyst free reaction. All of the obtained compounds were characterized by analysis of their 1H NMR and 13C NMR, IR spectra, and FT mass spectra. The UV and fluorescence emission spectra of 1–7 were investigated in the concentration range of 0.1–250 μM. As the results, the maximum emission wavelength of 1–7 was observed between 600 and 700 nm under the exciting wavelength of 250 nm for 1–5 and 300 nm for 6 and 7. The emission intensity is the strongest at a concentration of 60 μM for 2, 3, and 5–7, 30 μM for 1, and 0.1 μM for 4. [ABSTRACT FROM AUTHOR]

Pharmacological studies of the new fatty-aromatic amides, structural analogs of chlorobenzoylaminoadamantane (chlodantane), and non-covalent water-soluble complexes of chlodantane, adamantylbromophenylamine (bromantane) and ADC-918 were carried out. It was shown that complexation neutralized the actoprotective properties of the last three substances. The resulting complexes of arabinogalactan were inclusion compounds where the adaptogen molecule played the role of a guest; the arabinogalactan molecule, a host. Salt-like coordination complexes formed with glycyrrhizic acid. The new derivatives belonged to the third class of moderately toxic compounds. N-[(1R, 2RS)-Camphan-2-yl]-4-chlorobenzamide turned out to be the most promising compound in terms of the pharmacological profile and increased physical performance in the treadmill test by 23.22 – 25.20% 14 d after administration of the studied agent to mice. [ABSTRACT FROM AUTHOR]

This is the first work to report the removal of an aromatic amine (o-tolidine) from aqueous solutions using a carbon black (Vulcan XC 72 R) as adsorbent. The adsorbent material was characterized using Raman spectroscopy, scanning electron microscopy, energy dispersive spectroscopy, thermogravimetric analysis, and pH at the point of zero charge. The effects of contact time, pH, and initial concentration on o-tolidine adsorption were evaluated. Avrami kinetic model best described the adsorption process. Weber-Morris model showed that the aromatic amine adsorption mechanism is controlled by intraparticle and film diffusion on Vulcan XC 72 R. Temkin isotherm model described equilibrium results, with a maximum adsorption capacity of 64.00 mg g−1 at 25 °C. Thus, the results highlight the applicability of Vulcan XC 72 R as an effective and low-cost adsorbent to decontaminate effluents containing o-tolidine. [ABSTRACT FROM AUTHOR]

In order to determine optimum and ecologically acceptable conditions for aromatic amines (benzidine was chosen as an example) elimination by chara algae Nitella sp. a multi-factor experiment has been undertaken. The benzidine elimination process by chara algae was studied by variation of four factors, such as benzidine initial concentration in water solution, algae biomass, temperature, time and at the interaction of these factors as well. A mathematical model adequately describing the benzidine elimination process by chara algae at the optimal conditions has been obtained by means of design of experiments method. Suggested model might be useful for obtaining the data important for hydro botanical treatment facilities design and self-cleaning processes understanding. [ABSTRACT FROM AUTHOR]

A novel adsorbent, triazine core-containing resin (ODA-TRIAZ) was successfully, synthesized and employed for ultrahigh adsorptive removal of malachite green dye (MG) from water. The ODA-TRIAZ was found to be mesoporous in nature possessing abundant aromatic and amine functional groups that favors effective aqueous phase adsorption. Rapid equilibrium attainment for MG uptake was achieved that resulted in high maximum adsorption capacity (qmax) of 784.789 mg g−1 for MG at pH 8–10 and 25 °C, a significant improvement compared with similar reported resin-based adsorbents. Pseudo-second-order model well described the MG uptake kinetics while both Freundlich and Langmuir models describe the MG equilibrium behaviors. The mechanism of MG uptake was predominantly via multilayered adsorption mechanism with involvement of π–π stacking or hydrophobic interaction and hydrogen bonding that increases with increases in temperature and initial pH. The ODA-TRIAZ high reusability potentials with up to 95% performance after 5 consecutive adsorption–desorption cycles, an indication of been promising adsorbent for real water and wastewater treatment. [ABSTRACT FROM AUTHOR]

Heterocyclic amines (HCAs) are mutagenic compounds found in cooked meat. Recent epidemiological studies reported significant associations between dietary HCA exposure and insulin resistance and type II diabetes, and we recently reported that HCAs induce insulin resistance and glucose production in human hepatocytes. It is well known that HCAs require hepatic bioactivation by cytochrome P450 1A2 (CYP1A2) and N -acetyltransferase 2 (NAT2). NAT2 expresses a well-defined genetic polymorphism in humans that, depending on the combination of NAT2 alleles, correlates to rapid, intermediate, or slow acetylator phenotype that exhibits differential metabolism of aromatic amines and HCAs. No previous studies have examined the role of NAT2 genetic polymorphism in the context of HCA-mediated induction of glucose production. In the present study, we assessed the effect of three HCAs commonly found in cooked meat (2-amino-3,4-dimethylimidazo[4,5- f ]quinoline [MeIQ], 2-amino-3,8-dimethylimidazo[4,5- f ]quinoxaline [MeIQx], and 2-amino-1-methyl-6-phenylimidazo[4,5- b ]pyridine [PhIP]) on glucose production in cryopreserved human hepatocytes with slow, intermediate, or rapid NAT2 acetylator phenotype. HCA treatment did not affect glucose production in slow NAT2 acetylator hepatocytes, while a slight increase in glucose production was observed in intermediate NAT2 acetylators treated with MeIQ or MeIQx. However, significant increases in glucose production were observed in rapid NAT2 acetylators following each HCA. The current findings suggest that individuals who are rapid NAT2 acetylators may be at a greater risk of developing hyperglycemia and insulin resistance following dietary exposure to HCAs. [Display omitted] • HCAs promote insulin resistance and glucose production in human hepatocytes. • HCA-induced glucose production required N -acetyltransferase 2 (NAT2) metabolism. • Rapid NAT2 acetylators may be more susceptible to the metabolic effect of HCAs. [ABSTRACT FROM AUTHOR]

Various pyrimidine derivatives were synthesized via one-pot three-component condensation of aromatic aldehydes, malononitrile, and multiple amines using 1,1'-(butane-1,4-diyl)bis(1,4-diazabicyclo[2.2.2]octan-1-ium) hydroxide as a basic ionic liquid catalyst under solvent-free conditions. The advantages of this method are the simplicity of the procedure, short reaction times, high yields, no-column chromatographic separation, commercial availability of the preliminary materials, and reusability of the catalyst. [ABSTRACT FROM AUTHOR]

Amines are abundant in natural product chemistry and are readily available chemical raw materials. The C-N bonds of amines are difficult to break due to the large C-N bond energy. In recent years, chemists have developed a variety of activation methods for amino groups of amines. Among these reported methods, to convert amines into quaternary ammonium salts is preferred, for quaternary ammonium salts are readily available and stable. In recent years, great progress has been achieved in the study of transition metal-catalyzed construction of various C-X bonds involving aromatic amines and benzyl amines-derived quaternary ammonium salts by cleavage of C-N bonds. This review describes the transition metal-catalyzed reaction of quaternary ammonium salts to construct C-X bonds by cleavage of C-N bond. Moreover, if chiral benzylamines-derived quaternary ammonium salts are used, a variety of highly enantiomeric pure chiral organic compounds can also be obtained. The chirality of quaternary ammonium salts remained good in the products and all reactions underwent SN2-type configuration inversion. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) graphene is a promising active component for various engineering fields, but its performance is limited by the hidebound electrical conductivity levels and hindered electrical transport. Here we present a novel approach based on interlayer engineering, in which graphene oxide (GO) nanosheets are covalently functionalized with varied molecular lengths of diamine molecules. This has led to the creation of an unprecedented class of 3D graphene with highly adjustable electronic properties. Theoretical calculations and experimental results demonstrate that ethylenediamine, with its small diameter acting as a molecular bridge for facilitating electron transport, has the potential to significantly improve the electrical conductivity of 3D graphene. In contrast, butylene diamine, with its larger diameter, has a reverse effect due to the enlarged spacing of the graphene interlayers, resulting in conductive degradation. More importantly, the moderate conductive level of 3D graphene can be achieved by combining the interlayer spacing expansion effect and the π-electronic donor ability of aromatic amines. The resulting 3D graphene exhibits highly tunable electronic properties, which can be easily adjusted in a wide range of 2.56–6.61 S·cm−1 compared to pristine GO foam (4.20 S·cm−1). This opens up new possibilities for its use as an active material in a piezoresistive sensor, as it offers remarkable monitoring abilities. [ABSTRACT FROM AUTHOR]

In recent years, N-Myristoyltransferase (NMT) has been identified as a new target for the treatment of fungal infections. It is observed that at present, there are increased rates of morbidity and mortality due to fungal infections. Hence, a series of novel myristic acid derivatives were designed via molecular docking studies and ADMET studies by targeting NMT (N-Myristoyltransferase). The designed myristic acid derivatives were synthesized by converting myristic acid into myristoyl chloride and coupling it with aryl amines to yield corresponding myristic acid derivatives. The compounds were purified and characterized via FTIR, NMR and HRMS spectral analyses. In this study, we carried out a target NMT inhibition assay. In the NMT screening assay results, the compounds 3u, 3m and 3t showed better inhibition compared to the other myristic acid derivatives. In an in vitro antifungal evaluation, the myristic acid derivatives were assessed against Candida albicans and Aspergillus niger strains by determining their minimal inhibitory concentrations (MIC50). The compounds 3u, 3k, 3r and 3t displayed superior antifungal capabilities against Candida albicans, and the compounds 3u, 3m and 3r displayed superior antifungal capabilities against Aspergillus niger compared to the standard drug FLZ (fluconazole). Altogether, we identified a new series of antifungal agents. [ABSTRACT FROM AUTHOR]

Background: Search for the better anti-cancer agents become central part for many research teams as the current drugs in use suffer lack of specificity to the cancer targets. Design and development of target specific anti-cancer agents increase the potency and safety of the drugs. Materials and Methods: Current research intends to develop a novel series of the pyrimidine derivatives owing to the anti-cancer potential of the pyrimidine scaffold. In a multicomponent reaction approach, 4,5-disubstituted pyrimidines (4) were synthesized from three component coupling reaction of substituted enamine (1), an orthoester (triethoxy methane) (2) and ammonium acetate (3). 4,5-disubstituted pyrimidines (4) were oxidized to corresponding aldehyde derivative (5) via Stephen aldehyde synthetic process. Then the pyrimidine aldehyde coupled with various aromatic amines to produce final pyrimidine imine derivatives (6a-6j). By using IR, 1 H-NMR, and mass spectral studies, all the prepared derivatives were characterized and subjected to anti-cancer activity evaluation by MTT Assay. Four cancer cells (A 549 (lung), B16F10 (mouse skin melanoma), SiHA (cervical), MCF-7 (breast), and one normal fibroblast (L929)] were employed to study the anti-cancer potential of the synthesized pyrimidine derivatives. Results: The synthesized compounds produced in moderate to good yields with proposed scheme of synthesis. All the synthesized derivatives displayed noticeable cytotoxicity against the tested cancer cell lines. Conclusion: All of the evaluated cell lines were susceptible to the potential cytotoxicity of the newly synthesized novel pyrimidine derivative. These brand-new pyrimidine compounds may be transformed into potent anti-cancer lead molecules. [ABSTRACT FROM AUTHOR]

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[Display omitted] Reaction between tetracyanoethylene and N,N -dimethyl-or N -(2-pyridyl)hydrazines affords 5-amino-3,4-dicyano-pyrazoles. In cases of aromatic amines, replacement of one cyano group by amino one occurs thus giving N -(tricyano-vinyl)anilines. [ABSTRACT FROM AUTHOR]