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Semicarbazide-sensitive amine oxidase (SSAO) is both a soluble- and membrane-bound transmembrane protein expressed in the vascular endothelial and in smooth muscle cells. In vascular endothelial cells, SSAO contributes to the development of atherosclerosis by mediating a leukocyte adhesion cascade; however, its contributory role in the development of atherosclerosis in VSMCs has not yet been fully explored. This study investigates SSAO enzymatic activity in VSMCs using methylamine and aminoacetone as model substrates. The study also addresses the mechanism by which SSAO catalytic activity causes vascular damage, and further evaluates the contribution of SSAO in oxidative stress formation in the vascular wall. SSAO demonstrated higher affinity for aminoacetone when compared to methylamine (Km = 12.08 µM vs. 65.35 µM). Aminoacetone- and methylamine-induced VSMCs death at concentrations of 50 & 1000 µM, and their cytotoxic effect, was reversed with 100 µM of the irreversible SSAO inhibitor MDL72527, which completely abolished cell death. Cytotoxic effects were also observed after 24 h of exposure to formaldehyde, methylglyoxal and H2O2. Enhanced cytotoxicity was detected after the simultaneous addition of formaldehyde and H2O2, as well as methylglyoxal and H2O2. The highest ROS production was observed in aminoacetone- and benzylamine-treated cells. MDL72527 abolished ROS in benzylamine-, methylamine- and aminoacetone-treated cells (**** p < 0.0001), while βAPN demonstrated inhibitory potential only in benzylamine-treated cells (* p < 0.05). Treatment with benzylamine, methylamine and aminoacetone reduced the total GSH levels (**** p < 0.0001); the addition of MDL72527 and βAPN failed to reverse this effect. Overall, a cytotoxic consequence of SSAO catalytic activity was observed in cultured VSMCs where SSAO was identified as a key mediator in ROS formation. These findings could potentially associate SSAO activity with the early developing stages of atherosclerosis through oxidative stress formation and vascular damage.

L-amino acids (L-AAs) play different important roles in the physiology of all living organisms. Their chiral counterparts, D-amino acids (D-AAs) are increasingly being recognized as essential molecules in many biological systems. Secondary amino acids with cyclic structures, such as prolines, exhibit conformational rigidity and thus unique properties in the structural and protein folding. Despite their widespread occurrence, much less attention was paid to their chiral analysis, particularly when the minor, typically D-enantiomer, is present in low amounts in a complex biological matrix. In this paper, a cost-effective, chiral GC-MS method is described for capillary Chirasil-L-Val separation of nine cyclic secondary amino acid enantiomers with four-, five-, and six-membered rings, involving azetidine-2-carboxylic acid, pipecolic acid, nipecotic acid, proline, isomeric cis/trans 3-hydroxy, 4-hydroxyproline, and cis/trans-5-hydroxy-L-pipecolic acid in the excess of its enantiomeric antipode. The sample preparation involves in-situ derivatization with heptafluorobutyl chloroformate, simultaneous liquid-liquid micro-extraction into isooctane followed by amidation of the arising low-polar derivatives with methylamine, an evaporation step, re-dissolution, and final GC-MS analysis. The developed method was used for analyses of human biofluids, biologically active peptides containing chiral proline constituents, and collagen.

By measuring the hydrodynamic characteristics (viscosity, density of extraction mixture, and interfacial tension) and determining the composition of degradation products by the IR, CMS, and nuclear magnetic resonance methods, the efficiency of using solutions of methylamine and guanidine carbonates at the stage of intracycle regeneration was evaluated. It has been experimentally proven that, when using these solutions, the same efficiency is achieved as when using a sodium bicarbonate solution. The main products of radiation destruction of the 30% Tri-n-butyl-phosphate in Isopar-M extraction mixture irradiated after saturation with nitric acid are determined: dibutyl phosphoric and monobutyl phosphoric acids, carboxylic acids, ketones, carbonyl compounds, and hydrocarbons.

The reaction of 4-X-substituted 1-[(difluoromethyl)sulfinyl]-2,3,5,6-tetrafluorobenzenes (X = CF3, H, OMe) with methylamine and ammonia in MeCN, Et2O, and hydrocarbons occurs involves nucleophilic substitution in position 2 of the substrate. The reaction time increases with increasing donor ability of substituent X in the series X = CF3 < H < OMe, as well as with decreasing solvent polarity. Further substitution of fluorine in position 6 of the substrate by methylamine is also possible, but requires a higher reaction temperature. The reaction of ammonia with 1-[(difluoromethyl)sulfinyl]-4-methoxy-2,3,5,6-tetrafluorobenzene is accompanied by partial demethylation to form 2-[(difluoromethyl)sulfinyl]-3,4,6-trifluoro-5-methoxy-N-methylaniline and 4-[(difluoromethyl)sulfinyl]-2,3,5,6-tetrafluorophenol.

A model for the survival of the amino acid content in micrometeorites and its possible transformations upon atmospheric entry is described. Since any organic species released in the atmosphere at high altitudes would exhibit a limited lifetime with respect to the typical timescale for atmospheric mixing (due to the substantial radiation field of the early Sun), only the organic content inside the meteorites could have contributed to prebiotic chemistry. It is thus important to determine both the amino acid loss from meteorites, due to both degassing and chemical degradation, and the extent of the chemical transformation of amino acids subjected to the increased temperature due to friction with the atmosphere. According to the interplay between the potential energy barrier and the pre-exponential factor in rate coefficients, either diffusion or chemical processing might be the dominant process following the rising temperature upon atmospheric entry. The possibility of the elimination of water from glycine to form aminoketene, or CO2 to form methylamine, ultimately driven by gravitational energy, was examined along with the more conventional formation of a peptide bond between two glycine units to afford Gly&ndash, Gly. While retention, degassing, and decarboxylation are the fastest processes, each dominating in different ranges of the initial velocity and radius, the formation of either Gly&ndash, Gly from bimolecular water elimination or aminoketene from unimolecular water elimination appears to be negligible.

The first continuous flow process was developed to synthesize N-methyl secondary amines from alkyl mesylates and epoxides via a nucleophilic substitution using aqueous methylamine. A variety of N-m...

BACKGROUND: Persimmon tannin, extracted from young astringent persimmons, is a cheap waste biomass material. The abundant phenolic hydroxyl groups in persimmon tannin are known to display excellent affinity to Mo(VI). In addition, ligands containing N donor atoms, as brilliant adsorption groups, can strongly interact with Mo(VI) when the groups are protonated under acidic conditions. Therefore, the introduction of nitrogen‐containing groups in persimmon tannin may be an effective method to improve the recovery capacity of biosorbent for Mo(VI) in aqueous solution. In this work, a series of adsorbents were prepared by immobilizing ethylenediamine or methylamine on the surface of persimmon tannin. RESULTS: Due to the abundant nitrogen‐containing groups and hydroxyl groups, the ethylenediamine modified persimmon tannin exhibited excellent maximum uptake capacity to Mo(VI) (478.02 mg·g⁻¹), which was superior to that of methylamine modified persimmon tannin. Further, the results of XPS and FT‐IR confirmed that Mo(VI) was adsorbed on the hydroxyl‐assisted nitrogen‐containing group modified persimmon tannin via coordination and electrostatic interaction. CONCLUSION: Furthermore, 99% of Mo(VI) was selectively recovered from coexisting ions by en‐CPT under appropriate acidic conditions (pH 1). Pseudo‐second‐order kinetic model best represented the adsorption process of Mo(VI) onto the en‐CPT. The adsorption equilibrium was achieved in a relatively short time (no more than 1 h). High recovery efficiency and excellent selective adsorption made the en‐CPT an ideal candidate for Mo(VI) recovery in practical applications. © 2020 Society of Chemical Industry (SCI)

A detailed chemical kinetic model has been developed for supercritical water oxidation (SCWO) of methylamine, CH3NH2, providing insight into the intermediates and final products formed in this process as well as the dominant reaction pathways. The model was adapted from previous mechanisms, with a revision of the peroxyl radical chemistry to include imine formation, which has recently been identified as the dominant gas‐phase pathway in amine oxidation. The developed model can reproduce previous experimental data on methylamine consumption and major product formation to reasonable accuracy, although with deficiencies in describing the induction time. Our simulations indicate that oxidation of the •CH2NH2 radical to methanimine, CH2NH, is the major channel in methylamine SCWO, with subsequent hydrolysis of CH2NH providing the experimentally observed reaction products ammonia and formaldehyde. Integral‐averaged reaction rates were used to identify major reaction pathways, and a first‐order sensitivity analysis indicated that the concentration of CH3NH2 is most sensitive to OH radical kinetics. Overall, this work clarifies the importance of imine chemistry in the oxidation of nitrogen‐containing compounds and indicates that they are necessary to model these compounds in SCWO processes.

Dehydropolymerisation of methylamine borane (H3B⋅NMeH2) using the well‐known iron amido complex [(PNP)Fe(H)(CO)] (PNP=N(CH2CH2PiPr2)2) (1) gives poly(aminoborane)s by a chain‐growth mechanism. In toluene, rapid dehydrogenation of H3B⋅NMeH2 following first‐order behaviour as a limiting case of a more general underlying Michaelis–Menten kinetics is observed, forming aminoborane H2B=NMeH, which selectively couples to give high‐molecular‐weight poly(aminoborane)s (H2BNMeH)n and only traces of borazine (HBNMe)3 by depolymerisation after full conversion. Based on a series of comparative experiments using structurally related Fe catalysts and dimethylamine borane (H3B⋅NMe2H) polymer formation is proposed to occur by nucleophilic chain growth as reported earlier computationally and experimentally. A silyl functionalised primary borane H3B⋅N(CH2SiMe3)H2 was studied in homo‐ and co‐dehydropolymerisation reactions to give the first examples for Si containing poly(aminoborane)s., Getting poly(aminoborane)s: The well‐known Fe amido complex [(PNP)Fe(H)(CO)] (PNP=N(CH2CH2PiPr2)2) is a potent catalyst for the selective formation of poly(aminoborane)s from methylamine borane and a SiMe3‐substituted analogue. Mechanistic studies support a chain‐growth mechanism with polymer formation by nucleophilic attack at the terminus of a growing B−N chain.

Modern pharmacy and medicine can offer a substantial number of highly effective synthetic medicines. A great portion of these medicines falls into the group of 1,2,4-triazole derivatives. 1,2,4-Triazoles are distinguished by important pharmacological properties, including antimicrobial, antifungal, anti-inflammatory, hypoglycemic, while also being capable of stimulating the central nervous system. Undoubtedly, a constant increase of number of publications regarding the synthesis, characterization of biological, chemical, and physical properties of 1,2,4-triazole derivatives by both foreign and Ukrainian researchers promotes the search for promising compounds of this class of heterocyclic compounds globally. The purpose of our work was to synthesize and characterize structures of salts of 2-(((3-mercapto-5-methyl-4 H -1,2,4-triazole-4-yl)imino)methyl)benzoic acid, as potentially bioactive compounds. Materials and methods. The physical-chemical characterization of the synthesized compounds was conducted according to the guidelines provided by the State Pharmacopoeia of Ukraine. The melting point was determined using MPA100 apparatus. Elemental analysis was held using Elementar Vario L.cube analyzer. 1 H NMR spectra were recorded using Varian Mercury VX-200 spectrometer (1Н, 200 MHz). Chromatographic and mass-spectrometric data were obtained using Agilent 1260 Infinity LC system coupled with Agilent 6120 mass spectrometer. Results and discussion. 2-(((3-Mercapto-5-methyl-4 H -1,2,4-triazole-4-yl)imino)methyl)benzoic acid was used as the starting compound for the synthesis of the new structures. In order to afford the desired compounds, the starting material was subjected to salt formation reactions with ammonium hydroxide, sodium and potassium hydroxides, methylamine, ethylamine, dimethylamine, 1 -propylamine, 2 -propylamine, monoethanolamine, diethylamine, tert -butylamine, piperidine, piperazine, morpholine, 2-methylpiperidine, and 4-methylmorpholine whether in alcohol or water solutions. Conclusions. The chemical experiments resulted in 16 new substances, salts of 2-(((3-mercapto-5-methyl-4 H -1,2,4-triazole-4-yl)imino)methyl)benzoic acid. The chemical structure of the synthesized compounds was confirmed using instrumental methods, including 1 H NMR spectroscopy, LC-MS, and elemental analysis. The obtained salts will be used in further pharmacological research.

Controlling the absolute and relative stereochemistry of a seven-membered oxepane in the formation of HIV integrase inhibitor MK-1376 was accomplished through a strategy involving the use of asymmetric allylation and stereoconvergent, substrate-directed installation of an amine fragment. Surprising reactivity was demonstrated during the asymmetric allylation in which the allyl-pyrimidone product was formed reversibly. The stereoconvergent amine addition was accomplished through an elimination/addition sequence involving a quinone methide reactive intermediate, and nucleophilic trapping of the reactive quinone methide intermediate with methylamine. This novel approach delivered MK-1376, offering 100-fold greater productivity and 50-fold less waste than the initial synthetic chemistry route.

A highly efficient protocol for the amination of 4-fluoronitrobenzene by using methylamine aqueous solution as the amination reagent was developed. The reaction proceeds smoothly to provide the desired product in high yield and excellent purity within 15 min at 70 °C. The particle size of the product obtained in this approach was less than 100 μm. And the reaction media exhibited excellent reusability after recovering four times.

Potable reuse of wastewater is expanding, and ozonation for water reuse is becoming more common, either as a preoxidant before membranes or as part of ozone/biological activated carbon (O3/BAC) sys...

A new method for the direct synthesis of primary and secondary amides from carboxylic acids is described using Mg(NO3)2·6H2O or imidazole as a low-cost and readily available catalyst, and urea as a stable, and easy to manipulate nitrogen source. This methodology is particularly useful for the direct synthesis of primary and methyl amides avoiding the use of ammonia and methylamine gas which can be tedious to manipulate. Furthermore, the transformation does not require the employment of coupling or activating agents which are commonly required.

Triple-ion formation of tetrabutylphosphonium methanesulfonate [Bu4PCH3SO3] in methylamine solution has been reported quantitatively by conductometric study, and the observation has evident from the qualitative analysis of FT-IR spectroscopy. The ionic liquid exists as triple-ion state in low dielectric constant solution (methylamine solution having er

Functionally 4,6-disubstituted 1H-pyrazolo[3,4-d]pyrimidines are important compounds with various pharmacological activities. 1-Substituted 4-chloro-6-(chloromethyl)-1H-pyrazolo[3,4-d]pyrimidines are practically unexplored derivatives in this series. In this paper, it was shown that the nucleophilic substitution of 4-Chloro-6-(chloromethyl)-1-methyl-1H-pyrazolo[3,4-d]pyrimidine with methylamine produced selectively 4-substituted product, 6-(chloromethyl)-N,1-dimethyl-1H-pyrazolo[3,4-d]pyrimidin-4-amine. The structure of the synthesized compound was established by elemental analysis, high resolution mass-spectrometry, 1H, 13C-NMR, and IR spectroscopy, mass-spectrometry, and X-ray analysis.

Ferrate (Fe(VI)), a promising water treatment oxidant, can be used for micropollutant abatement or disinfection byproduct mitigation. However, knowledge gaps remain concerning the interaction between Fe(VI) and dissolved organic matter structures, notably primary amines. This study investigated degradation kinetics and products of several aliphatic primary amines by Fe(VI). Primary amines showed appreciable reactivity toward Fe(VI) (2.7−68 M−1s−1 at pH 7−9), ranking as follows: benzylamine > phenethylamine > phenylpropylamine > methylamine ≈ propylamine. Nitriles were the main oxidation products of the primary amines, with molar yields of 61−103%. Minor products included aldehydes, carboxylic acids, nitroalkanes, nitrite, nitrate, and ammonia. The buffering conditions were important. Compared to phosphate, borate enhanced the reactivity of the amines and shifted the products from nitriles to carbonyls. An evaluation of the effect potency of some cyano-compounds by an in vitro bioassay for oxidative stress response and cytotoxicity suggested that non-halogenated nitriles are unlikely to pose a significant threat because they were only toxic at high concentrations, acted as baseline toxicants and did not cause oxidative stress, unlike halonitroalkanes or halonitriles. The formation of non-halogenated nitriles is preferable to the formation of nitroalkanes arising from the ozonation of primary amines (other than amino acid N-terminals) because, during chlorination, nitriles remain unreactive while nitroalkanes lead to potent halonitroalkanes.

The first catalytic asymmetric cyclopropanation of diazo oxime ethers with olefins was developed. In the presence of a Ru(II)-Pheox catalyst, various optically active cyclopropyl oxime derivatives were obtained in high yields (up to 99%) with high enantioselectivities (up to 98% ee). Furthermore, optically active cyclopropyl oxime ethers could be successfully converted into the corresponding cyclopropyl methylamine derivatives via metal hydride and Grignard reagent mediated Beckmann rearrangement, which are potential candidates for the assessment of biological and pharmaceutical activities.

International audience; Hydrazine-boranes (HNNH·BH and HB·NHNH·BH) have been proposed for the storage of hydrogen, but these compounds have not created scope for extensive research works as ammonia- and methylamine-boranes have made these last decades. In the exciting research devoted to energy storage with environmentally friendly processes, hydrazine-borane, hydrazine-bisborane, and their simply substituted derivatives could provide a satisfactory response for hydrogen production and recyclability of the formed products. To date, knowledge of the physical and chemical properties of these compounds is still scarce. In this paper, the electronic structure of various hydrazine-boranes complexes is studied by ultraviolet-photoelectron spectroscopy (UV-PES), which is the experimental technique giving direct access to the energy of occupied molecular orbitals. Thus, UV-PE spectra were registered and first ionization energies were determined. Understanding of different types of interactions between nitrogen lone pairs and their variations by complexation has been our essential goal in these studies. In particular, clear stabilization of all molecular orbital energies is noted when complexation with borane takes place. Evolution of the σ bond during the hydrogen release process upon thermal activation has also been studied experimentally by UV-PES and supported by quantum chemical calculations.

The atmospheric oxidation of amines proceeds via initial radical attack at C–H or N–H bonds to form carbon‐ and nitrogen‐centered radicals, respectively. It is conventionally assumed that nitrogen‐centered aminyl radicals react slowly with oxygen in the troposphere and associate predominantly with the radicals •NO and NO2• to form toxic nitrosamines and nitramines. We have used theoretical kinetic modeling techniques to study the prototypical CH3N•H + O2 reaction and have shown that it proceeds to CH2NH + HO2• under tropospheric conditions with a rate coefficient of 3.6 × 10−17 cm3 molecule−1 s−1. Although this value is low compared to the competing NOx reactions (∼10−11 cm3 molecule−1 s−1), the much higher concentration of O2 versus NOx in air makes it the dominant process in the atmospheric oxidation of methylamine for NOx concentrations below 100 ppb. The mechanism identified here is available to amines with primary, secondary, and tertiary α carbons and suggests that they may be less likely to form nitramines and nitrosamines than is currently thought.

A series of 5,5′-(arylmethylene)bis[1,3-dimethyl-6-(methylamino)pyrimidine-2,4(1H,3H)-diones] have been synthesized by 2: 1 condensation of 1,3-dimethylbarbituric acid with armatic aldehydes in the presence of methylamine. The synthesized compounds have been characterized by 1H and 13C NMR, IR, and mass spectra and tested for their in vitro antibacterial activity against Bacillus subtilis, Staphylococcus aureus, and Pseudomonas aeruginosa. Some of the compounds have shown antibacterial activity exceeding that of ampicillin used as reference drug.

Iron is an essential element in nonheme enzymes that plays a crucial role in many vital oxidative transformations and metabolic reactions in the human body. Many of those reactions are regio- and stereospecific and it is believed that the selectivity is guided by second-coordination sphere effects in the protein. Here, results are shown of a few engineered biomimetic ligand frameworks based on the N4Py (N,N-bis(2-pyridylmethyl)-N-bis(2-pyridyl)methylamine) scaffold and the second-coordination sphere effects are studied. For the first time, selective substitutions in the ligand framework have been shown to tune the catalytic properties of the iron(IV)-oxo complexes by regulating the steric and electronic factors. In particular, a better positioning of the oxidant and substrate in the rate-determining transition state lowers the reaction barriers. Therefore, an optimum balance between steric and electronic factors mediates the ideal positioning of oxidant and substrate in the rate-determining transition state that affects the reactivity of high-valent reaction intermediates.

A heterocyclic polyamide 6 (i.e. caprolactam (CPL; 90 mol%)/sebacic acid (SBA; 5 mol%)/1,3-cyclohexanebis (methylamine)(CHM; 5 mol%) copolyamide) with superior transparency, haze, hygroscopicity and crystallinity to an ordinary polyamide 6 (PA 6) based on CPL (100 mol%) have prepared by the design of appropriate prescriptions. The transparency, haze, hygroscopicity, and crystallinity of lab-made heterocyclic PA 6 are 86.5%, 13.2%, 1.36% (24hr)/1.89% (48hr), and 11.5%, respectively, while those of PA 6 are 26.0%, 94.2%, 1.80% (24hr)/2.45% (48hr), and 24.0%, respectively. Experimental results demonstrate that physical properties of lab-made heterocyclic PA 6 deeply depend on its heterocyclic structure and introduction of SBA and CHM into PA 6 can effectively improves optical, hygroscopic, thermal decomposition, and crystalline characteristics of PA 6, revealing that it is a highly potential polymeric material for optical films, electrical encapsulation, and food packages.

Tow new α-aminophosphonic acids, Ethyl hydrogen [(2-methoxyphenyl)(methylamino) methyl]phosphonate (2-EHMAP) and Ethyl hydrogen [(3-methoxyphenyl)(methylamino) methyl]phosphonate (3-EHMAP) were synthesized by the reaction between Methylamine, 2- or 3-Methoxybenzaldehyde and Diethylphosphite in THF solution with FeCl3. The structures of the title compounds were determined by UV–Vis, FT-IR, 1H, 13C, 31P NMR and MS spectra and confirmed by centesimal analysis. Their inhibition efficiency on the corrosion of mild steel in 1 M HCl and 0.5 M H2SO4 solutions was studied by weight loss, polarization curves and electrochemical impedance spectroscopy (EIS). The surface morphology of XC38 simple was studied by scanning electron microscopy (SEM) and Atomic Force Microscopy (AFM). The experimental results show that both molecules are mixed inhibitors and that their adsorptions on the surface of mild steel obey the Langmuir isotherm and that the 2-EHMAP exhibit better inhibition efficiency. Quantum chemical calculations were performed by using DFT to study the influence of molecular structure on the inhibition efficiency; theoretical findings are in good accord with the experimental observations.

Aliphatic amines as common constituents of dissolved organic nitrogen (DON) exhibit high reactivity during ozonation; however, our understanding of their degradation mechanisms is very limited. In this study, methylamine (MA) and ethylamine (EA), as well as their secondary and tertiary amines (DMA, DEA, TMA and TEA) were chosen as aliphatic amine models and their degradation mechanisms during ozonation were investigated by using the DFT method. The oxygen-transfer reaction occurs initially and rapidly in the ozonation of all the above amines with a ΔG≠ value of 8-10 kcal mol-1 in great agreement with the experimental rate constant of 104 to 107 M-1 s-1. Moreover, N-oxide as the main degradation product for tertiary amines directly forms after oxygen-transfer, while nitroalkanes as main products for secondary and primary amines are yielded after a series of reactions mediated by hydroxylamine and nitrosoalkane with a ΔG≠ value of 10-13 kcal mol-1. Regarding the minor N-dealkylated products for all amines, alkylamino alcohol is an important intermediate possibly generated via a radical reaction pathway with a ΔG≠ value of 21-34 kcal mol-1. Additionally, comparison of the reactivity of aliphatic amines, hydroxylamines and alkylamino alcohols with ozone was made and elucidated in this study. The results are expected to expand our understanding of the degradation mechanisms for nitrogenous compounds during ozonation.

A new, dynamic diastereomeric crystallization method has been developed, in which the mother liquors are continuously separated, racemized over a fixed-bed catalyst, and recirculated to the crystallizer in a resolution-racemization-recycle (R3) process. Separating the racemization from crystallization overcomes problems of using catalysts in situ, that suffer conflicting sets of conditions, inhibition, and separation. Continuous racemization has been achieved through the covalent attachment of [IrCp*I2]2 SCRAM catalyst to Wang resin solid support to give a fixed-bed catalyst. One tertiary and a variety of secondary optically enriched amines have been racemized efficiently, with residence times compatible with the crystallization (2.25-30 min). The catalyst demonstrates lower turnover (TOF) than the homogeneous analogue but with reuse shows a long lifetime (e.g., 40 recycles, 190 h) giving acceptable turnover number (TON) (up to 4907). The slow release of methylamine during racemization of N-methyl amines was found to inactivate the catalyst, which could be partially reactivated using hydroiodic acid. Dynamic crystallization is achieved in the R3 process through the continual removal of the more soluble diastereomer and supply of the less soluble one. The solubility of the diastereomers was determined, and the difference correlates to the rate of resolution but is also affected by the rates of racemization, crystal growth, and dissolution. A variety of cyclic and acyclic amine salts were resolved using mandelic acid (MA) and ditoluoyl tartaric acid (DTTA) with higher resolvability (S = yield × d.e.) than the simple diastereomeric crystallization alone. Comparing resolvabilities, resolutions were 1.6-44 times more effective with the R3 process than batch, though one case was worse. Further investigation of this revealed an unusual thermodynamic switching behavior: rac-N-methylphenethylamine was initially resolved as an (S,S)-bis-alkylammonium tartrate crystal but over time became the equivalent (R,S) salt. Thermal, mixing, concentration, stoichiometry, and seeding conditions were all found to affect the onset of the switching behavior which is only associated with difunctional resolving reagents.

International audience; Au(I) complexes catalyze iso-Pictet-Spengler reactions. Ethylamine or methylamine chains were introduced at C2, C4 or at the nitrogen atom of the indole ring, and the corresponding substrates were reacted in the presence of aldehydes and catalytic amounts of Au(I) complexes, leading to a variety of polycyclic scaffolds. Selectivity could be achieved in the course of a double iso-Pictet-Spengler reaction involving two successive aldehydes, leading to highly complex molecules.

The protonated perovskite-like titanate H2La2Ti3O10 has been used to produce organic-inorganic hybrids with simple organic molecules: methylamine, methanol, monoethanolamine, and n-butylamine. The optimal pathways for the preparation of such hybrids are summarized. Solid-state NMR, combined with thermal analysis, Raman, and IR spectroscopy, has been applied to determine the bonding type in the obtained organic-inorganic hybrids. It has been found that, in the methanolic hybrid, the organic residues are covalently bound to the inorganic matrix. In contrast, in the methylamine and n-butylamine hybrids, the organic molecules are intercalated into the inorganic matrix in cationic forms. The structure of the monoethanolamine hybrid is composite and includes both the covalently bound and intercalated organic species.

A novel series of mononuclear five-coordinated pseudohalido-Cu(II) complexes displaying distorted square bipyramidal: [Cu(L1)(NCS)2] (1), [Cu(L2)(NCS)2] (2) and [Cu(L3)(NCS)]ClO4 (5) as well as distorted trigonal bipyramidal: [Cu(isp3tren)(N3)]ClO4 (3), [Cu(isp3tren)(dca)]ClO4 (4) and [Cu(tedmpza)(dca)]ClO4&middot, 0.67H2O (6) geometries had been synthesized and structurally characterized using X-ray single crystal crystallography, elemental microanalysis, IR and UV-vis spectroscopy, and molar conductivity measurements. Different N-donor amine skeletons including tridentate: L1 = [(2-pyridyl)-2-ethyl)-(3,4-dimethoxy)-2-methylpyridyl]methylamine and L2 = [(2-pyridyl)-2-ethyl)-(3,5-dimethyl-4-methoxy)-2-methyl-pyridyl]methylamine, and tetradentate: L3 = bis(2-ethyl-di(3,5-dimethyl-1H-pyrazol-1-yl)-[2-(3,4-dimethoxy-pyridylmethyl)]amine, tedmpza = tris[(2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl]amine and isp3tren = tris[(2-isopropylamino)ethyl)]amine ligands were employed. Molecular structural parameters such as nature of coligand, its chelate ring size and steric environment incorporated into its skeleton, which lead to adopting one of the two limiting geometries in these complexes and other reported compounds are analyzed and correlated to their assigned geometries in solutions. Similar analysis were extended to other five-coordinated halido-Cu(II) complexes.

A novel chloro-substituted zinc-phosphate, (C8N2H20)[ZnCl(PO3(OH))], has been synthesized by a slow evaporation method in the presence of 1,3-cyclohexanebis- (methylamine), which acts as a template. The structure consists of vertex linked ZnO3Cl and PO3(OH) tetrahedral, assembled into corrugated porous layers [ZnCl(PO3(OH))2]∞ with (4.82) topology. The optical properties were also investigated using Diffuse Reflecting Spectroscopy (DRS), showing that the title compound has semiconducting properties. In addition, the catalytic activity of (C8N2H20)[ZnCl(PO3(OH))]2 has been tested in the acetalisation reaction of aldehydes. The title compound displayed a high catalytic activity with practically total conversion in many examples using MeOD as solvent and as the sole source of acetalisation. More importantly, the reaction crudes are very clean and only the preferred products are found in the NMR spectra., R. P. H. and I. A. thank the Spanish Ministerio de Economía, Industria y Competitividad (MINECO-FEDER CTQ2017-88091-P and PGC2018-093451-B-I00) and Diputación General de Aragón (DGA) (Research Groups E07_17R and E17_17R) for financial support of their research.

The synthesis of chiral amines is of central importance to pharmaceutical chemistry, and the inclusion of fluorine atoms in drug molecules can both increase potency and slow metabolism. Optically enriched β-fluoroamines can be obtained by the kinetic resolution of racemic amines using amine transaminases (ATAs), but yields are limited to 50%, and also secondary amines are not accessible. In order to overcome these limitations, we have applied NADPH-dependent reductive aminase enzymes (RedAms) from fungal species to the reductive amination of β-fluoroacetophenones with ammonia, methylamine and allylamine as donors, to yield β-fluoro primary or secondary amines with >90% conversion and between 85 and 99% ee. In addition, the effect of the progressive introduction of fluorine atoms to the β-position of the acetophenone substrate reveals the effect of mono-, di- and tri-fluorination on the proportion of amine and alcohol in product mixtures, shedding light on the promiscuous ability of imine reductase (IRED)-type dehydrogenases to reduce fluorinated acetophenones to alcohols.

A detailed chemical kinetic model for oxidation of methylamine has been developed, based on theoretical work and a critical evaluation of data from the literature. The rate coefficients for the reactions of CH3NH2 + O2 → CH2NH2 / CH3NH + HO2, CH3NH2 + H→CH3 + NH3, CH3NH→CH2NH2, andCH3NH + O2 → CH2NH + HO2 were calculated from ab initio theory. The mechanism was validated against experimental results from batch reactors, flow reactors, shock tubes, and premixed flames. The model predicts satisfactorily explosion limits for CH3NH2 and its oxidation in a flow reactor. However, oxidation in the presence of nitric oxide, which strongly promotes reaction at lower temperatures, is only described qualitatively. Furthermore, calculated flame speeds are higher than reported experimental values; the model does not capture the inhibiting effect of the NH2 group in CH3NH2 compared to CH4. More work is desirable to confirm the products of the CH3NH + NO reaction and to look into possible pathways to NH3 in methylamine oxidation.

Volatile amines including ammonia, methylamine, dimethylamine, ethylamine, and trimethylamine were extracted using a needle-type extraction device followed by determination using a gas chromatography–barrier discharge ionization detector. The analyte amines were extracted based on their reaction with an organic acid in the needle packed by the adsorbent. The extracted compounds were desorbed by heating the extraction needle in the GC injection port and introduced into a GC column. After optimization of the desorption process, the proposed method was quantitatively evaluated for linearity, repeatability, and sensitivity. The limits of detection for ammonia, methylamine, dimethylamine, ethylamine, and trimethylamine with an air sampling volume of 100 mL were 0.03, 0.1, 1, 0.06 and 0.05 µg L−1, respectively. The method was applied to the determination of amines from raw fish and raw meat samples.

A new efficient method for synthesizing promising heat shock protein inhibitors, N,N-dialkyl- 1-(2-alkylthiopyrimidin-4-yl)piperidin-4-amines, by the reaction of 2-alkyl-4-chlorothiouracils with 4-(N-alkyl-N-methylamino)piperidines was developed. 2-Alkyl-4-chlorothiouracils were synthesized by alkylation of 2-thiouracil with alkyl iodides and subsequent treatment of the intermediates with POCl3. 4-(N-Alkyl-N-methylamino)piperidines were prepared by reductive amination of 1-(tert-butoxycarbonyl)-4-piperidinone with methylamine followed by treatment of the intermediate with the appropriate aldehydes.

The major product of intramolecular [3 + 2]-cycloaddition of munchnones generated by heating syn- and anti-atropisomers of N-acetyl-N-[2-(cyclopent-2-en-1-yl)-6-methyl-, 2,4-dimethyl-, 2,5-dimethylphenyl)- and N-acetyl-N-[2-(cyclohex-2-en-1-yl)-6-methylphenyl]glycines with acetic anhydride was that formed from the anti isomer. Isomeric glycine derivatives having no methyl group in the ortho position of the aromatic ring gave rise to (1S*,3aR*,4S*,7S*,13S*)-1-methyl- and (1S*,3aR*,4S*,7S*,13S*)-3a-acetyl-1-methyl-4,5,6,7- tetrahydro-1,4,7-epimethanetriyl[1,3]oxazolo[3,4-a][1]benzazocin-3(3aH)-one as the major product. Treatment of 1,11-dimethyl- and 1,9,11-trimethyl-4,5,6,7-tetrahydro-1,4,7-epimethanetriyl[1,3]oxazolo[3,4-a][1]benzazocin- 3(3aH)-ones with methylamine in methanol on heating in a sealed ampule afforded epimethanetriylimidazobenzazocinones, whereas acid-stable compound with a methanocyclopenta[c]quinoline skeleton was formed under similar conditions from the 1,8,11-trimethyl analog.

The mechanisms of noncatalytic and autocatalytic addition–elimination reactions of dimethyl carbonate with methylamine have been studied in terms of wB97XD/6-311++G(df,p), M06/6-311++G(df,p), and PBE0/6-311++G(df,p) quantum chemical methods, and thermodynamic and activation parameters of these reactions have been calculated. The rate-determining stage is the formation of tetrahedral carbon intermediate. The addition–elimination mechanism is preferred over the autocatalytic SN2 mechanism determined by enhanced donor–acceptor and acid–base properties of amine complexes with alcohol associates in comparison to amines.

Aims & Objective: An efficient procedure for the synthesis of pyrido[2,1-a]isoquinoline derivatives in excellent yields was investigated using catalyst-free multicomponent reaction of phthaladehyde, methylamine, activated acetylenic compounds, alkyl bromides and triphenylphosphine in water under ultrasonic irradiation at room temperature. In addition, Diels- Alder reactions of pyrido[2,1-a]isoquinoline derivatives with activated acetylenic compounds under ultrasonic irradiation are investigated in two procedures. The advantages of this procedure compared to report methods are short time of reaction, high yields of product, easy separation of product, clean mixture of reaction and green media for performing reaction. In addition, because of having isoquinoline core in synthesized compounds, in this research antioxidant activity of some synthesized compounds was studied. Materials and Methods: To a stirred mixture of phthalaldehyde 1 (2 mmol) and methylamine 2 (2 mmol) in water (3 mL) under ultrasonic irradiation was added to activated acetylenic compounds 4 after 20 min. Alkyl bromide 3 and triphenylphosphine 5 react in another pot in water (3 mL) under ultrasonic irradiation for 15 min. After this time, this mixture was added to the first pot. After completion of the reaction, the solid residue was separated by filtration and washed with Et2O to afforded pure title compound 6. Results: In this work, generation of pyrido[2,1-a]isoquinoline derivatives 6 are performed using phthalaldehyde 1, methylamine 2, α-halo substituted carbonyls 3, activated acetylenic compounds 4 and triphenylphosphine 5 in water under ultrasonic irradiation condition at room temperature in excellent yield at short time. Conclusion: In summary, multicomponent reaction of phthaladehyde, methylamine, activated acetylenic compounds, alkyl bromides and triphenylphosphine in water under ultrasonic irradiation at room temperature produced pyrido[2,1-a]isoquinoline derivatives in excellent yields. Also, Diels-Alder reaction of pyrido[2,1-a]isoquinoline derivatives with activated acetylenic compounds and triphenylphosphine under ultrasonic irradiation is investigated in two procedures. Also, the antioxidant activities of 6a, 6c, 6g and 6i were evaluated by DPPH radical scavenging and ferric reducing power analyzes. The compounds 6a exhibit excellent DPPH radical scavenging activity and FRAP compared to synthetic antioxidants BHT and TBHQ. The chief benefits of our method are high atom economy, green reaction conditions, higher yield, shorter reaction times, and easy work-up, which agree with some principles of green chemistry.

Analysis of extended X-ray absorption fine structure (EXAFS) data for the Mn(IV)-oxo complexes [Mn(IV)(O)((DMM)N4py)](2+), [Mn(IV)(O)(2pyN2B)](2+), and [Mn(IV)(O)(2pyN2Q)](2+) ((DMM)N4py = N,N-bis(4-methoxy-3,5-di methyl-2-pyridylm ethyl)-N-bis(2-pyridyl)methylamine; 2pyN2B = (N-bis(1-methyl-2-benzimidazolyl)methyl-N-(bis-2-pyridylmethyl)amine, and 2pyN2Q = N,N-bis(2-pyridyl)-N,N-bis(2-quinolylmethyl)methanamine) afforded Mn=O and Mn-N bond lengths. The Mn=O distances for [Mn(IV)(O)((DMM)N4py)](2+) and [Mn(IV)(O)(2pyN2B)](2+) are 1.72 and 1.70 Å, respectively. In contrast, the Mn=O distance for [Mn(IV)(O)(2pyN2Q)](2+) was significantly longer (1.76 Å). We attribute this long distance to sample heterogeneity, which is reasonable given the reduced stability of [Mn(IV)(O)(2pyN2Q)](2+). The Mn=O distances for [Mn(IV)(O)((DMM)N4py)](2+) and [Mn(IV)(O)(2pyN2B)](2+) could only be well-reproduced using DFT-derived models that included strong hydrogen-bonds between second-sphere solvent 2,2,2-trifluoroethanol molecules and the oxo ligand. These results suggest an important role for the 2,2,2-trifluoroethanol solvent in stabilizing Mn(IV)-oxo adducts. The DFT methods were extended to investigate the structure of the putative [Mn(IV)(O)(N4py)](2+)·(HOTf)(2) adduct. These computations suggest that a Mn(IV)-hydroxo species is most consistent with the available experimental data.

Novel cis- and trans-2-(p-bromophenyl)-5-methylthiazolidin-4-ones, S,N-containing heterocyclic compounds, were provided in a cis-stereocomplementary and trans-stereocomplementary synthetic manner. cis-Selective cyclo-condensation proceeded between 2-sulfanylpropanoic acid (thiolactic acid) and an imine derived from 4-bromobenzaldehyde and methylamine, whereas Ti(OiPr)4 and Ti(OiBu)4-promoted trans-selective cyclo-condensation proceeded between benzyl 2-sulfanylpropanoate and the imine. The obtained cis- and trans-2-(p-bromophenyl)-5-methylthiazolidin-4-ones were successfully converted to 2-(3-furyl)phenyl derivatives and bis(pinacolato)diborane derivatives utilizing Suzuki–Miyaura and Miyaura–Ishiyama cross-coupling reactions, respectively, in an umpolung manner.

Reductive functionalization of CO2 with amines and a reductant, which combines both reduction of CO2 and C–N bond formation in one pot to produce versatile chemicals and energy-storage materials such as formamides, aminals, and methylamines that are usually derived from petroleum feedstock, would be appealing and promising. Herein, we give a brief review on recent developments in the titled CO2 chemistry by employing transition-metal-free catalysis, which can be catalogued as below according to the diversified energy content of the products, that is formamides, aminals, and methylamines being consistent with 2-, 4-, and 6-electron reduction of CO2, respectively. Notably, hierarchical reduction of CO2 with amines to afford at least two products, for example, formamides and methylamines, could be realized with the same catalyst through tuning the hydrosilane type, reaction temperature, or CO2 pressure. Finally, the opportunities and challenges of the reductive functionalization of CO2 with amines are also highlighted.1 Introduction2 2-Electron Reduction of CO2 to Formamide3 6-Electron Reduction of CO2 to Methylamine4 4-Electron Reduction of CO2 to Aminal5 Hierarchical Reduction of CO2 with Amines6 Conclusion

A series of 13 well-defined alkylglucuronamides [AGUA] surfactants with hydrophobic chains consisting of fatty alcohols (C8, C12, or C16) involved in a glucosidic bond has been synthesized in two steps from glucuronic acid or glucuronolactone. The nonionic polar heads are a sugar unit with an amide function derived from five different amines, i.e., methylamine, ammonia, ethanolamine, ethoxyethanolamine, and aminopropanediol. Their CMC values present variations from 0.03 to 29 mM, and their hydrophilic/lipophilic behaviors have been compared to conventional dodecyl polyethoxylated surfactants (C12Ej) using the PIT-slope methodology. They cover a large scale of the corresponding C12Ej with j varying from 5 to 8. Regarding functional properties, the novel alkylglucuronamides exhibit good foaming properties. Last but not least, two of them could be classified as easily biodegradable according to respirometric tests.

Reductive amination of carbonyl compounds constitutes one of the most efficient ways to rapidly construct chiral and achiral amine frameworks. Imine reductase (IRED) biocatalysts represent a versatile family of enzymes for amine synthesis via NADPH mediated imine reduction. The reductive aminases (RedAms) are a sub-family of IREDs which have recently been shown to catalyse imine formation as well as imine reduction. Herein, a diverse library of novel enzymes were expressed and screened as cell-free lysates for their ability to facilitate reductive amination, in order to expand the known suite of biocatalysts for this transformation and to identify more enzymes with potential industrial applications. A range of ketones and amines were examined and enzymes were identified that were capable of accepting benzylamine, pyrrolidine, ammonia and aniline. Amine equivalents as low as 2.5 were employed to afford up to >99% conversion and for chiral products, up to >98% e.e. could be achieved. Preparative-scale reactions were conducted with low amine equivalents (1.5 or 2.0) of methylamine, allylamine and pyrrolidine, achieving up to >99% conversion and 76% isolated yield.

[1′-(Diphenylphosphino)ferrocenyl]methylamine (1) reacts with Ph2PH/(CH2O)x or [Ph2P(CH2OH)2]Cl to give mixtures of Ph2PfcCH2NHCH2PPh2 and Ph2PfcCH2N(CH2PPh2)2 in which the triphosphine dominates (fc = ferrocene-1,1′-diyl). To avoid unwanted two-fold phosphinomethylation, the amine group in 1 was alkylated. As expected, the reaction of the N-methyl analogue Ph2PfcCH2NHMe (5), obtained by reductive methylation of the aldehyde Ph2PfcCHO, with [Ph2P(CH2OH)2]Cl, only led to the diphosphine Ph2PfcCH2N(Me)CH2PPh2 (6). The diphosphine was structurally characterized and further reacted with [PdCl2(MeCN)2] and [PdCl(Me)(cod)] (cod = η2:η2-cycloocta-1,5-diene), affording the respective trans-chelate complexes [PdCl(X){Ph2PfcCH2N(Me)CH2PPh2-κ2P,P′}] (7a: X = Cl; 7b: X = Me), which were also structurally authenticated by X-ray diffraction analysis.

The CO2-involved synthesis of chemicals is of great significance from a green and sustainable point of view. Herein, we present an efficient Co-based catalytic system composed of a commercially available Co salt, the tetradentate phosphine ligand P-(CH2CH2PPh2)3, and a base, denoted as [Co]/PP3/base, for the synthesis of formamides via the formylation of amines with CO2/H2. It was indicated that the selectivity of products (i.e., formamide or methylamine) could be tuned to some extent via changing the solvent and the base. Using ethanol as the solvent, the Co(ClO4)2·6H2O/PP3/K2CO3 system showed high activity for the production of formamides, affording product yields of 82–95%, together with its broad substrate scope. Exploration of the reaction mechanism indicated that formamide was formed with HCOOH as the intermediate, while the methylamine byproduct was produced with HCHO as the intermediate via the hydrogenolysis of dialkylaminomethane.

A one-pot, two-step, total synthesis of naturally occurring xenortides A, B, C and D, (Xens A-D) isolated from the bacterium Xenorhabdus nematophila, and an entire complementary set of stereoisomers, has been achieved. Compounds were synthesized utilizing an isocyanide-based Ugi 4-CR followed by facile N-Boc deprotection. The reaction sequence took advantage of the chiral pool of N-Boc protected amino acids (l-Leu/Val and d-Leu/Val) with aryl isocyanides, phenyl acetaldehyde and methylamine giving the desired Xens A-D (A and B >98% ee) and all subsequent stereoisomers in reasonable yields upon deprotection followed by separation of diastereomers. Also, detailed mechanistic insights for diastereoselectivity of (-)-Xen A, as a model in the Ugi 4-CR, has been described. Moreover, for the first time, this focused library was screened for cytotoxicity against a panel of epithelial cancer cell lines as well as normal cell lines with an MTT proliferation assay. The structure-activity relationship (SAR) study demonstrated that tryptamides Xen B and D were more active than phenylethylamides Xen A and C. Furthermore, (-)-Xen B (IC50 = 19-25 μM) and ent-(+)-Xen D (IC50 = 21-26 μM) gave the highest cytotoxicity and they were also found to be non-toxic toward normal cells. Importantly, the SAR results indicate that the stereochemistry at C8 and C11 in (-)-Xen B and ent-(+)-Xen D play a critical role in cytotoxic activity.

International audience; For the first time the investigation of water molecule complexed with methylamine (CH 3 NH 2) in solid neon was performed from 80 to 6000 cm-1 using Fourier transform infrared spectroscopy. From concentration effects and with the help of theoretical results we have identify several vibrational transitions for CH 3 NH 2 dimer, CH 3 NH 2-H 2 O, and CH 3 NH 2-(H 2 O) 2 complexes. For the CH 3 NH 2-H 2 O complex, where the two submolecules interacting through hydrogen bonding, the infrared (IR) spectral changes (frequencies as well as intensities) indicate that the water playing the role of the proton donor, in agreement with the previous theoretical works. Theoretical calculations at the second-order Møller-Plesset level have been performed to obtain their equilibrium geometries and vibrational spectra at the harmonic level and comparison with experimental data allows us to give structures of observed complexes.