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N-Formylation of amines with CO2 as a cheap and non-toxic C1-feedstock and hydrosilane reducing agent is a practical and environment friendly method to synthesize formamides. This study describes an efficient and chemoselective mono-N-formylation of amines using CO2 and phenylsilane under mild conditions using a porous metal–organic framework (MOF)-supported single-site cobalt catalyst (pyrim-UiO-Co). The pyrim-UiO-Co MOF has a UiO-topology, and its organic linkers bear a pyridylimine ligated Co catalytic moiety. A wide range of aliphatic and aromatic amines are transformed into desired N-formamides in moderate to excellent yields under 1–5 bar CO2. Pyrim-UiO-Co is tolerant to various functional groups and could be recycled and reused at least 10 times. Mechanistic investigation using kinetic, spectroscopic and density functional theory studies suggests that the formylation of benzylamine proceeds sequentially via oxidative addition of PhSiH3 and CO2 insertion, followed by a turn-over limiting reaction with an amine. Our work highlights the importance of MOF-based Earth-abundant metal catalysts for the practical and eco-friendly synthesis of fine chemicals using cheap feedstocks. [ABSTRACT FROM AUTHOR]

N-Formylation of amines with CO2 as a cheap and non-toxic C1-feedstock and hydrosilane reducing agent is a practical and environment friendly method to synthesize formamides. This study describes an efficient and chemoselective mono-N-formylation of amines using CO2 and phenylsilane under mild conditions using a porous metal–organic framework (MOF)-supported single-site cobalt catalyst (pyrim-UiO-Co). The pyrim-UiO-Co MOF has a UiO-topology, and its organic linkers bear a pyridylimine ligated Co catalytic moiety. A wide range of aliphatic and aromatic amines are transformed into desired N-formamides in moderate to excellent yields under 1–5 bar CO2. Pyrim-UiO-Co is tolerant to various functional groups and could be recycled and reused at least 10 times. Mechanistic investigation using kinetic, spectroscopic and density functional theory studies suggests that the formylation of benzylamine proceeds sequentially via oxidative addition of PhSiH3 and CO2 insertion, followed by a turn-over limiting reaction with an amine. Our work highlights the importance of MOF-based Earth-abundant metal catalysts for the practical and eco-friendly synthesis of fine chemicals using cheap feedstocks. [ABSTRACT FROM AUTHOR]

Presence of heavy metals in wastewater is a critical environmental issue, and efficient extraction of the metals remains a challenging task. In this study, the adsorption behavior of Ce(III), Hg(II), and Cu(II) metal ions using MCM-48 material modified with acid and base functional groups was examined. The modified materials were characterized using various techniques, including XRD, BET, FT-IR, NMR, and SEM, which revealed that the materials' properties remained unchanged after modification. The adsorption capacity of the modified materials for metal ions was then evaluated and was found that the amine-modified MCM-48 material exhibited the highest adsorption efficiency. Precisely, the amine-modified material achieved an adsorption capacity of 97% for Ce(III), 98% for Hg(II), and 90% for Cu(II) after 180 min of adsorption. These results highlight the effectiveness of amine functionalization in enhancing the adsorption capacity of silica material for heavy metals. [ABSTRACT FROM AUTHOR]

The results of application of new catalytic reagents based on cerium dioxide nanoparticles and its composites with gold, hydroxyapatite, and polyvinylpyrrolidone to the reductive alkylation of heteroaromatic and heterocyclic amines with methyl 4formylbenzoate are presented. A highly efficient method for preparation of benzylated heterocyclic and aromatic amines is proposed. [ABSTRACT FROM AUTHOR]

Axially chiral N-arylindoles bearing a stereogenic C-N axis are unique important scaffolds in natural products, advance materials, pharmaceuticals and privileged chiral ligands or catalysts. Herein, we report the direct synthesis of C-N axially chiral N-arylindoles through a Pd-catalyzed free amine-directed atroposelective C-H olefination enabled by a spiro phosphoric acid (SPA) ligand. A wide range of enantioenriched N-aromatic amine indoles were obtained in high yields with good enantioselectivities (35 examples, up to 91% yield and up to 96% ee). The chiral products with free amine group offer an effective functional handle for down-stream diversity-oriented synthesis. [ABSTRACT FROM AUTHOR]

The World Health Organization (WHO) reports that tuberculosis (TB) is one of the top 10 leading causes of global mortality. The increasing incidence of multidrug-resistant TB highlights the urgent need for an intensified quest to discover innovative anti-TB medications In this study, we investigated four new derivatives from the quinoxaline-2-carboxylic acid 1,4-dioxide class. New 3-methylquinoxaline 1,4-dioxides with a variation in substituents at positions 2 and 6(7) were synthesized via nucleophilic aromatic substitution with amines and assessed against a Mycobacteria spp. Compound 4 showed high antimycobacterial activity (1.25 μg/mL against M. tuberculosis) and low toxicity in vivo in mice. Selection and whole-genomic sequencing of spontaneous drug-resistant M. smegmatis mutants revealed a high number of single-nucleotide polymorphisms, confirming the predicted mode of action of the quinoxaline-2-carboxylic acid 1,4-dioxide 4 as a DNA-damaging agent. Subsequent reverse genetics methods confirmed that mutations in the genes MSMEG_4646, MSMEG_5122, and MSMEG_1380 mediate resistance to these compounds. Overall, the derivatives of quinoxaline-2-carboxylic acid 1,4-dioxide present a promising scaffold for the development of innovative antimycobacterial drugs. [ABSTRACT FROM AUTHOR]

Understanding and managing the generation of odour nuisances throughout the raw rubber processing industry are vital to reduce the impact on the community. This paper aims to review literature on odour studies and management in the raw rubber processing industry. The generation of odour is typically associated with microbial reactions occurring in non-rubber components. The most offensive compound groups commonly discussed in the literature are sulfur derivatives and volatile fatty acids due to their unpleasant characteristics and low-odour threshold. Major sources of these odorants are from effluent treatment of the latex processing plant and exhaust gas from the drying process at the block rubber processing plant, respectively. However, studies performed on the composition of rubber emissions also reported the presence of other compound groups such as aldehyde, ester, amine and aromatic, which could potentially contribute to the odour emissions. Single or multiple odour assessment methods can be applied based on the objective of the odour assessment. Olfactory and chemical testings were generally applied to evaluate the odour concentration, offensiveness and identification of potential odorants, while odour wheel and dispersion modelling were employed to assess the impact on the community. Odour legislations mainly used olfactory techniques and dispersion modelling to control the odour emissions by limiting the odour release at a tolerable limit. Numerous mitigation measures have been studied and performed upstream and downstream of rubber processing, such as utilising biological methods and aerated effluent treatment that produces less odour, chemical substitution and installation of wet scrubber to reduce the odour emissions from drying process. Nevertheless, the literature is lacking studies conducted at the industrial scale on odour generation and mitigation where knowledge can be applied to develop an appropriate odour management strategy in the current industrial scenario to mitigate the odour effectively. [ABSTRACT FROM AUTHOR]

5-Amino-substituted 3-bromo-1-(1,1-dioxothietan-3-yl)-4-nitro-1H-pyrazoles were synthesized via the reactions of 3,5-dibromo-1-(1,1-dioxothietan-3-yl)-4-nitro-1H-pyrazole with aliphatic, aromatic, and heterocyclic amines. The structures of the synthesized compounds were confirmed by IR, PMR, and 13C NMR spectroscopy and mass spectrometry. According to in silico calculations, they were predicted to have no toxic risks (mutagenicity, tumorigenicity, reproductive effects, irritating effects), low toxicity (class IV-V), and acceptable oral bioavailability (based on the topological polar surface area indicator). All synthesized compounds, regardless of the amine structure, showed significant antidepressant activity after a single intraperitoneal injection to male mice in the forced swimming test that was comparable to that of amitriptyline, while 1-[3-bromo-1-(1,1-dioxothietan-3-yl)-4-nitro-1H-pyrazol-5-yl]-4-methylpiperazine (compound IIi) had a significant sedative effect in the open field test. The results of a comprehensive assessment of the biological activity of the synthesized compounds in vivo/in silico indicated that the class of 5-amino-substituted pyrazole derivatives was promising for further research. [ABSTRACT FROM AUTHOR]

The diazotization reaction of p-fluoroaniline from aromatic amines with 5,5-dimethylcyclohexane-1,3-dione was studied, as a result 2-(2-(p-fluorophenyl)hydrazone)-5,5-dimethylcyclohexane-1,3-dione (FHDCD) was synthesized and its structure was confirmed by single crystal X-ray diffraction (XRD) technique. The crystal packing was governed by various intermolecular interactions which was inspected by Hirshfeld surface analysis. 2D fingerprint plots were formed to find the contact that has most significant contribution in crystal packing. Enrichment ratio was calculated in order to find the contact that has highest propensity to form crystal packing interaction. Void analysis was carried out to predict the mechanical response of the crystal. Moreover, interaction energy calculations were performed at HF/3-21G electron density model to further inspect the supramolecular assembly of the crystal. [ABSTRACT FROM AUTHOR]

Lambertianic acid was selectively transformed at the carboxylic group. Synthetic methods for natural labdanoids, i.e., lambertianic acid methyl ester and lambertianol, were proposed. New N-containing diterpenoid derivatives with alkyl(aryl)amide, dialkylamide, hydrazide, N-hydroxycarbamoyl, and nitrile groups in the C-4 position of the labdane skeleton were synthesized via reactions of lambertianic acid chloride with aliphatic and aromatic amines, amino acids, hydrazine, and hydroxylamine. Compounds with higher cytotoxicity than lambertianic acid against MCF-7, HeLa, and HepG2 (MTT assay) human tumor cell lines were obtained. The IC50 value of the most active lambertianic acid N-hydroxycarbamoyl derivative was 15 μM (selectivity index >7). [ABSTRACT FROM AUTHOR]

We have developed a visible‐light‐mediated synthesis of 3‐arylsulfonylated thioflavones using an in situ‐activation strategy. The reaction proceeds through a one‐pot, three‐component pathway, without the need for sensitive or harsh reaction conditions. Organic photocatalysts were employed to generate aryl radicals more efficiently from aryl diazonium salts generated in situ. This method enables the synthesis of 3‐arylsulfonylated thioflavones from aryl amines and methylthiolated alkynones, utilizing potassium metabisulfite as an inexpensive source of sulfur dioxide. The resulting products were obtained under mild reaction conditions. This approach provides an efficient alternative pathway for synthesizing thioflavone derivatives, which are prevalent among various bioactive compounds. [ABSTRACT FROM AUTHOR]

Batch adsorption tests were conducted to assess the potential of a novel clay-biomass composite, namely kaolinite clay-pumpkin seed cake composite in removing an anionic (acid orange-7, AO-7) and a cationic (methylene blue, MB) dye. Physico-chemical characterization of the composite was performed by scanning electron microscopy, Fourier transform infrared (FTIR), X-ray diffraction and thermogravimetric analysis. After adsorption, FTIR results of the composite showed presence of carboxylic acid, aromatic amine, and O–H functional groups due to adsorption of MB and AO-7 onto the composite surface. Kinetic tests showed that the removal process followed pseudo-second-order model for both the dyes. Adsorption capacity of the composite for AO-7 and MB was found to be 268.8 mg/g and 119.7 mg/g, respectively, by Langmuir isotherm model. Reusability study of the composite showed a removal in the range of 82–86% in three adsorption–desorption cycles for both the dyes. For optimization study, response surface methodology based on the central composite design was applied to evaluate the effect of four independent variables, namely solution pH, contact time, adsorbent dose and initial dye concentration with dye removal as the response variable. The models predicted removals of 91.2% and 85.7% for AO-7 and MB at optimum conditions. Results of the study show the potential of kaolinite-pumpkin seed cake composite as an adsorbent for removal of cationic and anionic dyes. [ABSTRACT FROM AUTHOR]

Heterogenous BPDC−RuO2−CeO2 catalyst derived from Ce−BPDC MOFs can successfully enable the oxidation of amines to nitriles under mild conditions (1 atm O2, H2O as a solvent, room temperature). The catalytic system has the good compatibility with benzylic and aliphatic amines. Lewis acid‐base pairs [Ru−O−Ce−Vö] formed by the combination of acidic oxygen vacancy and basic oxygen pair Ru−O−Ce on the surface of the catalyst is the key factor for the catalytic activity. The mechanical experiments indicate that amines adopt the step‐by‐step dehydrogenation process to nitriles in this transformation. Moreover, the catalyst could be recycled up to six times without the evident loss of catalytic activity and the change of morphology. [ABSTRACT FROM AUTHOR]

The number of cigarette capsule users is increasing; however, a comprehensive epidemiological investigation comparing the harmfulness of capsule and non-capsule cigarettes, particularly concerning the composition of flavor components and mainstream smoke, is lacking. The present study aimed to investigate the effect of capsule burst on the compound composition of mainstream smoke by quantifying the Hoffmann list and flavor (geraniol, eugenol, menthofuran, and pulegone) in mainstream smoke with and without crushing the capsules. The findings indicate that while tar values tended to increase when the capsules were burst, there was no significant change observed in the other Hoffmann list components, such as nicotine, benzo[α]pyrene, tobacco-specific nitrosamines, aromatic amines, and phenolics. However, when the capsules burst, menthofuran and pulegone, which were present in the capsule and could cause toxicity, were found in the mainstream smoke via the International Standard Organization (1.5–4.0 μg/cig and 5.13–6.00 μg/cig smoking regime) and Health Canada Intense (12.8–18.2 μg/cig and 22.77–24.67 μg/cig smoking regime). Therefore, understanding the capsule composition is important, as the toxic components of the capsules can be inhaled as smoke, posing a potential health risk. [ABSTRACT FROM AUTHOR]

Non‐canonical amino acids (ncAAs) are useful synthons for the development of new medicines, materials, and probes for bioactivity. Recently, enzyme engineering has been leveraged to produce a suite of highly active enzymes for the synthesis of β‐substituted amino acids. However, there are few examples of biocatalytic N‐substitution reactions to make α,β‐diamino acids. In this study, we used directed evolution to engineer the β‐subunit of tryptophan synthase, TrpB, for improved activity with diverse amine nucleophiles. Mechanistic analysis shows that high yields are hindered by product re‐entry into the catalytic cycle and subsequent decomposition. Additional equivalents of l‐serine can inhibit product reentry through kinetic competition, facilitating preparative scale synthesis. We show β‐substitution with a dozen aryl amine nucleophiles, including demonstration on a gram scale. These transformations yield an underexplored class of amino acids that can serve as unique building blocks for chemical biology and medicinal chemistry. [ABSTRACT FROM AUTHOR]

The global demand for intelligent sensing of aromatic amines has consistently increased due to concerns about health and the environment. Efforts to improve material design and understand mechanisms have been made, but highly efficient non‐contact sensing with host–guest structures remains a challenge. Herein, we report the first example of non‐contact, high‐contrast sensing of aromatic amines in a hydrogen‐bonded organic framework (HOF) based on a nitro‐modified stereo building block. Direct observation of binding interactions of trapped amines is achieved, leading to charge separation‐induced emission quenching between host and guests. Non‐contact sensing of aniline and diphenylamine is realized with quenching efficiencies up to 91.7 % and 97.0 %, which shows potential for versatile applications. This work provides an inspiring avenue to engineer multifunctional HOFs via co‐crystal preparations, thus enriching applications of porous materials with explicit mechanisms. [ABSTRACT FROM AUTHOR]

Moreover, 2-aminobenzoic acids having electron-delocalization substituents, such as phenyl, acetyl, carbamate, and urea gave no yield of the corresponding products (entries 5-7). [35][36][37] We found that the nucleophilicity of nitrogen of 2-(benzylamino)benzoic acids was crucial to result in good yields of products from 2-(benzylamino)benzoic acids bearing electron-donating substituents on benzene ring. Keywords: quinazolinediones; cylic ureas; organocatalysis; intramolecular C-N amide bond formation; Tiemann rearrangement EN quinazolinediones cylic ureas organocatalysis intramolecular C-N amide bond formation Tiemann rearrangement 2052 2058 7 10/09/23 20231024 NES 231024 Graph Quinazolinediones are one of the most important nitrogen-containing heterocyclic compounds due to their common occurrence in natural products. Another key factor of the reaction was the electrophilicity of -chloroaldoxime I O i -methanesulfonates resulting in good yields with electron-withdrawing substituents and moderate yields from aliphatic -chloroaldoxime I O i -methanesulfonates. [Extracted from the article]

DABCO promoted one‐pot three‐component reaction of aromatic amines, dialkyl but‐2‐ynedioates and MBH nitriles of isatins selectively afforded two diastereomeric spiro[indoline‐3,4′‐pyridines] in comparable yields. On the other hand, DABCO promoted cyclization of dialkyl but‐2‐ynedioates and MBH carbonates of isatins in DCM at room temperature gave spiro[cyclopentane‐1,3′‐indoline] derivatives, while the reaction of dialkyl but‐2‐ynedioates and MBH nitriles of isatins in chloroform at 70 °C resulted in unique cyclopenta[c]quinolone derivatives with ring‐opening of isatin moiety. A plausible reaction mechanism was rationally proposed to explain formation of the different products. [ABSTRACT FROM AUTHOR]

However, for this endeavor we would directly use aniline B 22 b [21] to conclude our MCR procedure, because necessity required it; condensation of aniline B 22 b with either propionaldehyde or isobutyraldehyde had failed to afford a sufficiently pure imine to proceed. Keywords: ortho -quinone methides; marilines; imines; dihydrooxazoles; anilines; isoindolin-1-ones; phthalimidines; salicylaldehydes EN ortho -quinone methides marilines imines dihydrooxazoles anilines isoindolin-1-ones phthalimidines salicylaldehydes 3297 3302 6 09/29/23 20231018 NES 231018 Graph Numerous phthalimidines found in nature display a wide range of biological activities. The solution was quenched with saturated NaHCO SB 3 sb solution (3 mL) and extracted with Et SB 2 sb O (3 × 3 mL). Specifically, we have shown that various I o i -QM intermediates can be engaged by anilines, dihydrooxazoles, and imines to arrive at N-arylated, N-hydroxy ethylated, and free-N amines, respectively. [Extracted from the article]

Notably, instead of using ( I E i )-3-bromoprop-1-ene-1-sulfonyl fluoride ( B 2a b ), the use of ( I E i )-3-chloroprop-1-ene-1-sulfonyl fluoride ( B 2b b ) for the nucleophilic substitution reaction with aniline ( B 1a b ) was also examined. [60] Herein, we report an efficient protocol for constructing , -unsaturated -amino sulfonyl fluorides via chemo- and stereoselective nucleophilic substitution reactions of ( I E i )-3-bromoprop-1-ene-1-sulfonyl fluoride with aromatic amines in the presence of a base (Scheme 2). Keywords: , -unsaturated -amino sulfonyl fluorides; allylic amines; vinyl sulfonyl fluorides; click chemistry; covalent inhibitors EN , -unsaturated -amino sulfonyl fluorides allylic amines vinyl sulfonyl fluorides click chemistry covalent inhibitors 3373 3381 9 09/29/23 20231018 NES 231018 Graph As highly important building blocks for various bioactive compounds, allylamines are found widely in natural products and pharmaceutical molecules [1] such as colchicine, [8] dehydroabietylamine, [9] and terbinafine [4] (Figure 1a). [59] (2) The primary amine firstly undergoes a nucleophilic substitution reaction with ( I E i )-3-bromopropen-1-ene-1-sulfonyl fluoride to produce the desired product which then transforms into a sulfonyl amide via a SuFEx reaction. [Extracted from the article]

Organic amines are important compounds present in a wide variety of products, which makes the development of new systems for their detection an interesting field of study. New organometallic complexes of group 9 [MCp*X(2′-R-2-py-SBF)] (M = Ir, Rh; R = H, X = Cl (6), R = H, X = OAc (7), R = CHO, X = Cl (8)), and [IrCp*Cl(2′, 7-diCHO-2-py-SBF)] (9) (Cp* pentamethylcyclopentadienyl, SBF = 9,9'-spirobifluorene) bearing bidentate C–N ligands based on 9,9′-spirobifluorene were obtained and characterized by NMR spectroscopy, mass spectrometry, IR spectroscopy, and X-ray diffraction analysis when possible. The formation of a Schiff base to give complexes with the formula [MCp*Cl(2′-CH=NR-2-py-SBF)] (M = Ir, Rh; R = alkyl or aryl (10–12)), through condensation of an amine, and the aldehyde group present in these new complexes was studied leading to a selective reactivity depending on the nature of the amine and the metal center. While the iridium complexes only react with aromatic amines, the rhodium derivative requires heat for those but can react at room temperature with aliphatic amines. [ABSTRACT FROM AUTHOR]

Calixarenes are known as fascinated macromolecules due to their flexible structure that can be cast into different fields of application. These macromolecules have been used as quick and highly selective functional material for the extraction and separation of metal ions. This study explores metal ion removal efficiency of new calixarene coated silica resin from aqueous environment through solid phase extraction. The calixarene-coated silica resin (CCS resin) was synthesized and characterized by FTIR, SEM, XRD, EDS and BET. Static and dynamic adsorption experiments were followed to check the removal efficiency of CCS resin. Adsorption experiment shows that, CCS resin has strong potential for the removal of divalent and trivalent metal ions as compare to monovalent metal ions. Adsorption data have been evaluated by applying Langmuir, Freundlich, D-R models and Thomas dynamic adsorption models. The adsorption isotherm of the CCS resin agreed well with the Langmuir adsorption equation with regression coefficient of 0.99 and good monolayer adsorption capacities such as 3.22, 2.95, 3.04, 3.11, 2.81 and 2.82 (mol.g−1) for Hg2+ Pb2+ La3+ Cr3+ Al3+ and Fe3+ respectively. The D-R isotherm model suggests that the adsorption process follow ion exchange mechanism with mean sorption energy falls in the range of 9.0–16 KJ.mol−1. Moreover, the exhaustion capacity of column was calculated by using the Thomas model, which shows very small qo value with good fit to data (R2 =0.99). The thermodynamic and kinetic studies have also been performed, which reveals that the reaction is spontaneous and exothermic in nature and follows pseudo second-order kinetics. [ABSTRACT FROM AUTHOR]

Aryl amines are of constant interest in organic synthesis owing to their ubiquity in natural products, pharmaceuticals, and organic materials. However, C−H amination or pre‐functionalization frequently results in uncontrollable site selectivity, over activation and the generation of inseparable mixtures of regio‐isomers. Here we present a novel metal free Dötz‐type aminobenzannulation reaction that circumvents the selectivity issues inherent in aromatic chemistry, as well as the use of stoichiometric unstable organolithium reagents and toxic chromium complexes. The concept of utilizing readily available isocyanides and Morita–Baylis–Hillman (MBH) carbonates to achieve 1,1‐dipoles cross‐coupling to construct ketenimine is the key to success, which has been experimentally and computationally verified. The tandem 6π‐electrocyclization/aromatization process offers a versatile method for synthesizing functionalized anilines, fused aryl amines and fused heteroaryl amines. [ABSTRACT FROM AUTHOR]

5,6-Dihydrophenanthridines are prepared from aryl amines via intramolecular addition to N-tethered arynes under mild conditions. A new o-silylaryl triflate precursor was developed to increase reactivity and enable electron-rich and electron-poor aryl amines to undergo cyclisation. A complete switch in product selectivity occurs when the reaction is conducted in air, affording the corresponding phenanthridin-6(5H)-one as the sole product under otherwise identical reaction conditions. [ABSTRACT FROM AUTHOR]

We describe continuous-flow N-methylation with formaldehyde and H2 using heterogeneous Pd catalysts as a green synthetic method to access N-methyl amines. The catalyst exhibited excellent activity for aliphatic and aromatic amines. The developed method was also applied to sequential hydrogenation reactions to access challenging N-monomethyl amines. [ABSTRACT FROM AUTHOR]

Keywords: heterogeneous catalyst; 3-aminoalkylated indoles; solvent-free protocol; microwave-assisted; multicomponent reaction; one-pot synthesis EN heterogeneous catalyst 3-aminoalkylated indoles solvent-free protocol microwave-assisted multicomponent reaction one-pot synthesis 3153 3158 6 09/11/23 20231004 NES 231004 Graph Multicomponent reactions (MCRs), [1] primarily focusing on concepts such as atom economy and green chemistry have achieved considerable attention of scientific community globally. To the best of our knowledge no report has been published for the synthesis of 3-alkylaminoalkylated indoles with primary amines under microwave irradiation treated over heterogeneous catalyst in one-pot three-component reaction conditions. Heterogeneous catalyst, 3-aminoalkylated indoles, solvent-free protocol, microwave-assisted, multicomponent reaction, one-pot synthesis. [Extracted from the article]

Alternating current (AC) electrolysis is an emerging field in synthetic chemistry, however its mechanistic studies are challenged by the effective characterization of the elusive intermediate processes. Herein, we develop an operando electrochemical mass spectrometry platform that allows time‐resolved mapping of stepwise electrosynthetic reactive intermediates in both direct current and alternating current modes. By dissecting the key intermediate processes of electrochemical functionalization of arylamines, the unique reactivities of AC electrosynthesis, including minimizing the over‐oxidation/reduction through the inverse process, and enabling effective reaction of short‐lived intermediates generated by oxidation and reduction in paired electrolysis, were evidenced and verified. Notably, the controlled kinetics of reactive N‐centered radical intermediates in multistep sequential AC electrosynthesis to minimize the competing reactions was discovered. Overall, this work provides direct evidence for the mechanism of AC electrolysis, and clarifies the underlying reasons for its high efficiency, which will benefit the rational design of AC electrosynthetic reactions. [ABSTRACT FROM AUTHOR]

A one-pot protocol was developed to prepare new thiazol-2(3H)-imines in efficient yields. Therefore, the reaction of the appropriate aromatic amine, phenyl isothiocyanate and chloroacetone (ratio 1:1:1) was mediated using different solvents and bases. The optimized protocol was to conduct the reaction in ethanol at reflux in the presence of 1.2 equivalents of sodium acetate. The reaction produced the regioisomeric (Z)-N-aryl-3-phenylthiazol-2(3H)-imine, as detected by 1D and 2D NMR spectral data. Using a similar protocol, new arene- or chromene-linked thiazol-2(3H)-imines were prepared by the use of the respective α-bromoketones. The new products were screened against six different bacterial strains. In general, chromene-linked thiazol-2(3H)-imines displayed superior antibacterial activity over other products. Thiazol-2(3H)-imines linked to 6-methyl and 6-methoxy-2-oxo-2H-chromene units had the most effective antibacterial activity with MIC/MBC values of 2.0/4.0 and 1.9/3.9 µM, respectively, against Staphylococcus aureus, Streptococcus mutans, and Escherichia coli strains. [ABSTRACT FROM AUTHOR]

A mild, efficient one-pot three-component reaction of primary and secondary amines with carbon disulphide and a,b-unsaturated compounds providing dithiocarbamates has been developed employing in situ generated tetraethylammonium superoxide in aprotic solvent at room temperature. [ABSTRACT FROM AUTHOR]

As for the importance of 1-indanone derivatives in this project, 5,6-dimethoxy-2-methylene-2,3-dihydro-1H-inden-1-one has been synthesized by evaluating the old methods and examination of new methods. α-β unsaturated derivatives of 5,6-dimethoxy-1-indanone and diverse nucleophiles containing piperidine, N-methyl piperazine, morpholine, sodium azide, imidazole, benzimidazole, and pyrazole were reacted under Michael addition reaction condition and resulted in a variety of compounds with different stability. The possibility of retro-Michael reaction has been examined on the obtained products. The progress of this reaction depends on the stability of the synthesized 1-indanone derivatives. The results show compounds with aliphatic amines (piperidine, N-methyl piperazine, morpholine) have more appetency for participation in retro-Michael reaction vs compounds with aromatic amines (Imidazole, benzimidazole, pyrazole, except indole). The derivatives of aromatic amines usually show acceptable stability to the extent that they can be purified through column chromatography in contact with silica gel. Nevertheless, indole as an aromatic nucleophile is an exception; it has not completed the Michael addition reaction, and the final product in contact with silica gel under purification conditions using column chromatography performs the retro-Michael reaction. FT-IR, 1H, and 13C NMR spectroscopy as well as elemental analysis supported the predicted structure of the product. [ABSTRACT FROM AUTHOR]

Effectively inhibiting the formation of heterocyclic amines (HAs) and advanced glycation end products (AGEs) is crucial to human health. In the present study, chemical model systems were used to evaluate the inhibitory effects of seven hydrocolloids on HA and AGE formation. The results showed that hydrocolloids effectively inhibited the formation of two major AGEs. However, their inhibitory action against HA formation showed unexpected results, wherein alginic acid, carrageenan and konjac glucomannan promoted the formation of 2-Amino-1-methyl-6-phenylimidazo [4,5-b]pyridine (PhIP), harmane, norharmane and 2-amino-3,8-dimethyl-imidazo [4,5-f]-quinoline (MeIQx). Only chitosan and pectin showed significant inhibitory effects on HAs, reducing HA levels by 34.5–56.3% and 30.1–56.6%, respectively. In grilled beef patties, the addition of 1.5% chitosan and pectin significantly decreased AGE and HA content by 53.8–67.0% and 46.9–68.1%, respectively. Moreover, it had a limited impact on quality and sensory properties. Further mechanism studies conducted in model systems revealed that chitosan and pectin decreased the formation of key intermediates of AGEs and HAs. These findings suggest that chitosan and pectin are powerful inhibitors against AGE and HA formation with minimal impact on food quality. Therefore, their application in meat preparation and processing could effectively decrease human dietary exposure to HAs and AGEs. [ABSTRACT FROM AUTHOR]

A series of new N-(1,3-dioxoisoindolin-4-yl)acetamide derivatives were designed and synthesized via a condensation reaction between N-(1,3-dioxo1,3-dihydro isobenzofuran-4-yl)acetamide and various aliphatic and aromatic amines in water as an environmentally friendly solvent. All synthesized compounds (NPD 1--14) molecular structure was confirmed by their FTIR, ¹H NMR, 13C NMR, and mass spectroscopy. The final target compounds were screened for their in vitro antiproliferative activity by taking 5-Fluorouracil (5-FU) as a reference drug. Among 14 newly synthesized compounds, five compounds were shown to be effectively cytotoxic against the MCF7 cells. In comparison to the standard medication drug 5-FU (CC50 = 11.219 ± 0.847), the synthesized compounds NPD-8 (CC50 = 16.14 ± 2.08 μM) and NPD-12 (CC50 = 11.26 ± 1.158 μM) demonstrated the most active against the MCF7 cells. Furthermore, in silico study was performed to find molecular level interaction of active compounds with anticancer drug target enzyme NUDT5 inhibitors block hormone signaling in breast cancer cells. The compound NPD-12 showed the highest molecular binding energy -8.3 kcal/mol which interacted more effectively than the reference drug 5-FU binding energy -4.6 kcal/mol. These synthesized N-(1,3-dioxoisoindolin-4-yl) acetamide derivatives have been identified as a potential class of chemicals for further research as plausible new anticancer entities. [ABSTRACT FROM AUTHOR]

Compounds with a 3-oxabicyclo[3.3.1]nonane core were prepared from limonene and aromatic aldehydes containing methoxy groups and phthalaldehydes in the presence of montmorillonite K10 and were converted to aromatic amines containing this heterocycle. Some of the products were found to exhibit inhibitory activity in the reaction catalyzed by human tyrosyl-DNA phosphodiesterase 1 in the micromolar range. Bromo derivatives of amines, compounds 6b and 7b, which combine high inhibitory activity and low cytotoxicity, are promising for further studies in order to create new agents for the use in combined anticancer therapy. [ABSTRACT FROM AUTHOR]

The reactions of saturated monobasic carboxylic acids with functionally substituted primary aromatic amines (3-amino-2-naphthol, benzo[d]thiazol-2-amine, and 4,4′-oxydianiline) with TaCl5 (0.2 equiv.) were found to be accompanied by the selective formation of carboxylic acid amides of various structures. A mechanism for the amidation of carboxylic acids in the presence of TaCl5 was proposed. [ABSTRACT FROM AUTHOR]

Tattooing has been an enduring form of body art since ancient times, but it carries inherent health risks, primarily due to the complex composition of tattoo inks. These inks consist of complex mixtures of various ingredients, including pigments, solvents, impurities and contaminants. This literature review aims to shed light on the organic and inorganic contaminants present in tattoo inks prior to the implementation of the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH) regulation in 2022. This review shows that the most common contaminants are polycyclic aromatic hydrocarbons (PAHs), with a concentration range of 0.005–201 mg/kg, mainly detected in black tattoo inks, and primary aromatic amines (PAAs), with a concentration range of 0.5–1100 mg/kg, and heavy metals such as lead (0.01–14.0 mg/kg) and chromium(VI) (0.16–4.09 mg/kg) which are detected in almost all tattoo inks. When compared to the new concentration limits outlined in REACH, it is clear that a significant part of these contaminants would be considered non-compliant. However, the results of the review are limited due to the lack of quantitative data on contaminants in tattoo inks. In addition, the future implementation of REACH is expected to lead to changes in the composition of tattoo inks, which will affect the presence of contaminants. [ABSTRACT FROM AUTHOR]

Chiral amino-group compounds are of significance for human health, such as biogenic amino acids (AAs), dipeptides, and even various drugs. Enantiospecific discrimination of these chiral compounds is vital in diagnosing diseases, identifying pathological biomarkers and enhancing pharmaceutical chemistry research. Here, we report a simple and rapid 19F NMR-based strategy to differentiate chiral AAs, dipeptides, and amines, that were derivatized with (R)-2-(2-fluorophenyl)-2-hydroxyacetic acid ((R)-2FHA). As a result, 19 proteinogenic AAs (37 isomers) as well as Gly could be concurrently resolved. Moreover, various mirror-image dipeptides, such as Ser–His, Leu–Leu, and Ala–Ala, were commendably recognized. Intriguingly, we found that the absolute configuration of AAs in the N-terminus of dipeptides decided the relative 19F chemical shifts between two enantiomers. Besides, the ability of this method for enantiodiscrimination was further demonstrated by non-AA amines, including aromatic and aliphatic amines, and even amines having chiral centers several carbons away from the amino-group. The structurally similar antibiotics, amoxicillin and ampicillin, were well discriminated. Furthermore, this method accurately determines the de or dr values of non-racemic mixtures. Therefore, our strategy provides an effective approach for 19F NMR-based enantiodiscrimination and diastereomeric purity determination of amino-group compounds. [ABSTRACT FROM AUTHOR]

Intriguing luminescent properties of boranil complexes have gained a prominence. Here, we report the synthesis and optical properties of star‐shaped boranil complexes. The strategy involves one‐step synthesis by a simple mixing triformylphloroglucinol with various aromatic amines in the presence of diisopropylethyl amine (DIPEA), and the complexing reagent of BF3⋅Et2O in chloroform at 80 °C for 24 hours. The complexes are obtained in good yields (60–85 %). These boranil complexes have strong fluorescence in both solution (λmax=466–605 nm) and solid (λmax=612–659 nm) states, with the fluorescence quantum yields varying from 1.5–57 % in chloroform. The emission color of the complexes has been tuned from blue to red by varying the aryl‐substituents in the complexes. Further understanding of the optical and electronic properties is obtained theoretically using DFT computations. [ABSTRACT FROM AUTHOR]

Two blue emitting materials, 4,4'-(chrysene-6,12-diyl)bis(N,N-diphenylaniline) (TPA-C-TPA) and 12-(4-(diphenylamino)phenyl)-N,N- Diphenylchrysen-6-amine (TPA-C-DPA) were prepared with the composition of chrysene core moiety and dipenylamine (DPA) and triphenylamine (TPA) moieties as the side group. Two compounds were used to emitting layer as the dopants (EMLs) in doped device. The doped device using TPA-C-TPA showed current efficiency of 2.49 cd/A and external quantum efficiency of 4.26% at a current density of 10 mA/cm2. The doped device using TPA-C-DPA exhibited CE of 2.28 cd/A and EQE of 3.52% at a current density of 10 mA/cm2. TPA-C-TPA and TPA-C-DPA show the Commission Internationale de L'Eclairage (CIE) coordinates of (0.15, 0.06) and (0.14, 0.06) corresponding to the electroluminescence peak at 439 and 444 nm. [ABSTRACT FROM AUTHOR]

Excited State Intramolecular Proton Transfer (ESIPT), originally discovered and explored in depth in a number of extensive photophysical studies, is more recently rediscovered as a powerful synthetic tool, offering rapid access to complex polyheterocycles. In our prior work we have employed ESIPT in aromatic o-keto amines and amides, leading to diverse primary photoproducts—complex quinolinols or azacanes possessing a fused lactam moiety—which could additionally be modified in short, high-yielding postphotochemical reactions to further grow complexity of the heterocyclic core scaffold and/or to decorate it with additional functional groups. Given that sulfonamides are generally known as privileged substructures, in this study we pursued two goals: (i) To explore whether sulfonamides could behave as proton donors in the context of ESIPT-initiated photoinduced reactions; (ii) To assess the scope of subsequent complexity-building photochemical and postphotochemical steps, which give access to polyheterocyclic molecular cores with fused cyclic sulfonamide moieties. In this work we show that this is indeed the case. Simple sulfonamide-containing photoprecursors produced the sought-after heterocyclic products in experimentally simple photochemical reactions accompanied by significant step-normalized complexity increases as corroborated by the Böttcher complexity scores. [ABSTRACT FROM AUTHOR]

Absorption in amine solutions is a well-established advanced technology for CO2 capture. However, the fundamental aspects of the chemical reactions occurring in solution still appear to be unclear. Our previous investigation of aqueous monoethanolamine (MEA) and 2-amino-2-methyl-1,3-propanediol (AMPD), based on ab initio molecular dynamics simulations aided with metadynamics, provided new insights into the reaction mechanisms leading to CO2 capture and release with carbamate formation and dissociation. In particular, the role of water—strongly underestimated in previous computational studies—was established as essential in determining the development of all relevant reactions. In this article, we apply the same simulation protocol to other relevant primary amines, namely, a sterically hindered amine (2-amino-2-methyl-1-propanol (AMP)) and an aromatic amine (benzylamine (BZA)). We also discuss the case of CO2 capture with the formation of bicarbonate. New information is thus obtained that extends our understanding. However, quantitative predictions obtained using molecular simulations suffer from several methodological problems, and comparison among different chemical species is especially demanding. We clarify these problems further with a discussion of previous attempts to explain the different behaviors of AMP and MEA using other types of models and computations. [ABSTRACT FROM AUTHOR]

Toxic compounds such as heterocyclic amines (HAs) and polycyclic aromatic hydrocarbons (PAHs) can be produced during food processing, especially meat products. This study aims to monitor the formation of HAs and PAHs in fried pork fiber, a common meat product in Taiwan, at different processing conditions. A total of six experimental groups, including raw pork tenderloin, dried pork filaments, sesame oil-stir-fried pork at 160 °C for 15 min, sesame oil-stir-fried pork at 200 °C for 6 min, lard-stir-fried pork at 160 °C for 15 min, and lard-stir-fried pork at 200 °C for 6 min, were prepared and analyzed for formation of HAs via UPLC-MS/MS and PAHs via GC-MS/MS in triplicate. Frying in sesame oil or lard showed a greater content of total HAs in fried pork fiber processed at 160 °C for 15 min than at 200 °C for 6 min. However, in the same heating conditions, pork fiber fried in sesame oil produced a higher level of total HAs than that fried in lard. Of the various HAs in fried pork fiber, both Harman and Norharman were generated in the highest amount. The precursors, including reducing sugar, amino acid, and creatine/creatinine, played a vital role in HAs formation in fried pork fiber. For total PAHs, the highest level was shown for pork fiber fried in lard at 200 °C/6 min, followed by frying in sesame oil at 200 °C/6 min and 160 °C/15 min, and in lard at 160 °C/15 min. Like HAs, at the same heating condition, a greater content of total PAHs was produced in pork fiber fried in sesame oil than in lard. Notably, the highly toxic benzo[a]pyrene was undetected in fried pork fiber. The PAH precursor benzaldehyde was shown to generate at a much higher level than 2-cyclohexene-1-one and trans,trans-2,4-decadienal in fried pork fiber, and it should play a more important role in PAH formation. Principal component analysis (PCA) also revealed that the formation mechanism of HAs and PAHs in fried pork fiber was different. [ABSTRACT FROM AUTHOR]

Five new Betti base copper(II) complexes (C1–C5) are successfully synthesized and characterized spectroscopically. X-ray diffraction analysis confirmed the square planar geometry of complex C4. Their catalytic application in the C–H functionalization of aromatic amines for azidation was successfully demonstrated under ultrasonication. Complex C5 showed better catalytic activity and produced 2-azidoaniline with a yield of 85%, which is higher than the existing methods; it also performed better than commercial catalysts, with a higher efficiency. The reaction involves a lower catalytic loading and a short reaction time. Control experiments were carried out to predict the reaction pathway. Based on the results, a plausible mechanism involving a free radical pathway accompanied by a single electron transfer mechanism is proposed. The substrate scope was also studied with different aromatic amines, and the corresponding azides were obtained successfully. All the synthesized azides were employed in click reactions to obtain the respective triazoles. The biological relevance of the triazoles was also explored successfully using molecular docking studies against SARS-CoV-2 main protease Omicron P132H. [ABSTRACT FROM AUTHOR]

Four types of reactions (azo coupling, protolytic and oxidative condensation, ion association), accompanied by the formation of hydrophobic colored analytical forms of corresponding organic analytes, are proposed on an example of biologically active substances (aromatic amines, α-amino acids, antibiotics of aminoglycoside and β-lactam series, anionic surfactants). It is shown that, in these systems, the hydrophobicity of both the initial reactants, e.g., tetrafluoroborates of diazonium salts, and analytical forms (azo compounds, Schiff bases, Ruemann's purpura, ion associates with surfactants) can be increased. Possibilities of various methods for the derivatization of organic analytes with the formation of colored analytical forms with increased hydrophobicity for the best fixation on solid matrices and the development of test systems on their basis, which can be used to control the quality of various samples with rather good performance characteristics, are considered. [ABSTRACT FROM AUTHOR]