Reaction Of Aromatic Amines Research Articles

NaIO4/NH2OH-mediated Efficient Synthesis of Phosphoroamidates from Anilines and Triethyl Phosphite

AbstractA simple, efficient, and metal-free method was developed for the synthesis of phosphoroamidates. In essence, a mixture of sodium periodate (NaIO4) and hydroxylamine (NH2OH⸱HCl) was used in stoichiometric amounts to execute the phosphoramidation reaction of aromatic amines and triethyl phosphites at room temperature, in open air. This method offers a practical synthesis route to afford a diverse range of phosphoroamidates via the construction of P − N bonds, with excellent functional group compatibility and good yields under mild conditions.

Heterobimetallic Cu(I)/Fe(II) azomethine bridged coordination-organometallic hybrid complexes: Synthesis, luminescence, electrochemical and catalytic properties

A new series of heterobimetallic complexes of the type [Cu(L)(PPh3)2]X (1–4) [where L = trans-4-(ferrocenylideneamino)-1,5-dimethyl-2-phenyl-1H-pyrazol-3(2H)-one; PPh3 = triphenylphosphine, X = NO3−(1), ClO4− (2), BF4− (3) , PF6− (4)] were prepared by reaction of L with [Cu(MeCN)2(PPh3)2]X and characterized by elemental analysis, FTIR, 1H NMR, 31P NMR and UV–visible spectral studies. The thermal stability of (1–4) has been investigated by using thermogravimetric analysis (TGA). X-ray powder diffraction of the representative complex 1 used to clarify the crystal structure of the complex. The electrochemical behaviour of complexes (1–4) displayed quasireversible redox behaviour corresponding to Cu(I)/Cu(II) and Fe(II)/Fe(III) couples. All complexes show red emission as a result of ligand-ligand charge transfer (LLCT) and metal-ligand charge transfer (MLCT) or admixture of them. The catalytic efficiency of the complexes (1–4) was tested and it was found that the complex 4 worked as an effective catalyst for the C-N coupling reaction of aromatic amines and aryl halides.

Ambient catalyst-free oxidation reactions of aromatic amines using water radical cations.

Water radical cations play a pivotal role in various scientific and industrial fields due to their unique reactivity and capacity to drive complex chemical transformations. Here we explored the formation of quaternary ammonium cations through the direct oxidation reaction of aromatic amines, facilitated by water radical cations within water microdroplets. This process was monitored via in situ mass spectrometry and occurs under ambient conditions, negating the need for traditional chemical catalysts or oxidants and achieving an impressive yield of approximately 80%. Additionally, we employed a multi-channel spray system and enhanced both the reactant concentration and flow rate, thereby enabling gram-scale synthesis. These findings not only demonstrate the effectiveness and eco-friendliness of microdroplet chemistry but also provide a new understanding of heterogeneous ˙OH generation channels, thereby boosting the synthetic efficiency and sustainability of chemical processes.

Design, synthesis and characterization of new azoflavone derivatives through diazotisation - coupling reactions of aromatic amines (sulfanilic acid, 2-amino pyridine)

In this research, new azochalcone derivatives (6, 7) were synthesized by using three methods: the first one is diazotization - coupling method of different aromatic amines (sulfanilic acid, 2-aminopyridine) with chalcone (5), the second, aldol condensation method of azoaryl hydroxyacetophenone compounds with 4-dimethylamino benzaldehyde in presence of sodium hydroxide as a catalyst, the last one is method of aldol condensation of azoaryl hydroxyacetophenone compounds with 4-dimethylaminobenzaldehyde in presence of piperidine as an organic catalyst. The yield was the best by using the aldol condensation method with sodium hydroxide as a catalyst. New azoflavone derivatives (8, 9) with good yields (78-84 %) were also synthesized by performing cyclization reactions of azochalcone derivatives using iodine in dimethyl sulfoxide. The identity of the new compounds was determined using spectroscopic methods (FT-IR, 13C-NMR, 1H-NMR).

Molecular Diversity of Base Promoted Annulation of MBH Carbonates of Isatins and Dialkyl But‐2‐ynedioates

AbstractDABCO 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.

Structural Optimization of Luminescent Sulfur Dots for Solar Light Induced Efficient and Selective Oxidative Coupling Reactions of Aromatic Amines: A Complete Metal-Free Approach

Structural Optimization of Luminescent Sulfur Dots for Solar Light Induced Efficient and Selective Oxidative Coupling Reactions of Aromatic Amines: A Complete Metal-Free Approach

A General Protocol for the Chemo- and Stereoselective Construction of α,β-Unsaturated γ-Amino Sulfonyl Fluorides

AbstractA general protocol for the simple, efficient, and mild synthesis of α,β-unsaturated γ-amino sulfonyl fluorides is developed via a base-catalyzed N-alkylation reaction of aromatic amines with (E)-3-bromoprop-1-ene-1-sulfonyl fluoride. This transformation exhibits excellent chemo- and stereoselectivity, mild conditions, broad functional group compatibility and operational simplicity, making it a potentially valuable procedure in medicinal chemistry, chemical biology, and drug discovery.

Development of Practical Synthetic Methods Utilizing O-X or N-X Species

In chemical species containing of oxygen-halogens and nitrogen-halogens bonds, the halogen substituents show versatile reactivities, because oxygen and nitrogen atoms have higher electronegativity than halogen elements except for fluorine. I have focused on such monovalent halogen species and developed various synthetic methods utilizing O-X and N-X bonds which involves ionic and radical reactions. In this account, I describe such practical synthetic methodologies, which are CO2 fixation to unsaturated alcohols and amines, oxidative homo- and cross-coupling reactions of aromatic amines, novel generation of nitrile oxides from aldoximes, synthesis of oxazole-fused C60, iodoamination of alkenes in water, diaziridination of secondary amines, diastereodivergent diamination of unactivated alkenes, practical aziridination of electron-deficient alkenes, selective synthesis of nitrogen-bridged fullerenes, and benzylic C-H amidation.

A Reaction of N-Substituted Succinimides with Hydroxylamine as a Novel Approach to the Synthesis of Hydroxamic Acids

We describe a novel two-step approach for the synthesis of compounds with a hydroxyl-amide group (hydroxamic acids), which are widely known for their biological activity (histone deacetylase inhibitors, matrix metalloproteinases inhibitors and others). The first stage is the synthesis of N-substituted succinimide via the reaction of aromatic amine or carboxylic acid hydrazide with succinic anhydride. The second step involves the imide ring opening reaction by hydroxylamine. For both stages, universal synthetic methods are developed to exclude additional purification procedures for the target compounds. Sixteen hydroxamic acids are synthesized using the developed approach. Most of the compounds are obtained for the first time.

ELECTROPHYLIC REACTIONS OF CHLOROCARBOXYLIC ANHYDRIDE OF 1-METHYL-CYCLOHEX-3-ENE WITH 3-OXINDOLE AND N-PHENYLACETIC ACID

The properties of various functionally substituted nitrogen-organic com- pounds depend on their structure, the state and nature of the functional group in their molecule. Functionally substituted proteins obtained on the basis of the peptide bond of substituted heterocyclic compounds from various amino acids perform a physiological function that is widespread in nature and is important for the vital activity of the body. The direct acidification reaction of aromatic amines with aromatic carboxylic acids takes place under severe conditions at temperatures above 2800 C, the product is obtained with low yield, and at the same time additional products are formed. Among carbonaceous compounds, chloranhydrides of carbonic acids have the strongest electrophilic properties. The reaction of acylation with chloranhydrides proceeds in mild conditions and the reaction product is obtained with a high yield. Relevant carboxamide compounds have been obtained by acidification of N-phenylacetic acid and 3-oxindole with chlorocarboxylic anhydride of 1-methyl-cyclo- hex-3-ene. It has been found that the carboxamide compound obtained on the basis of N-phenylacetic acid formes carboxamide compound of 3-oxindole in the basic medium cycling intramolecularly.

Solid-state silica gel-catalyzed synthesis of fluorescent polysubstituted 1,4- and 1,2-dihydropyridines.

We present the green, highly atom-economical, solid-state silica gel-catalyzed synthesis of polysubstituted 1,4- and 1,2-dihydropyridines (DHPs) from commercially available materials, amines and ethyl propiolate. The DHP skeleton was assembled by heating the reactants and silica gel in a closed vessel. Aliphatic amines provided 1,4-isomers as the main or only DHP products, but the reactions of aromatic amines yielded a mixture of 1,4- and 1,2-isomers. To the best of our knowledge, this is the first example of the formation of a 1,2-DHP structure by the reaction of an amine with propiolic ester. Addition of 1 mass percent of H2SO4 to silica gel shifted the product distribution to 1,4-DHP as the main or the only isomer obtained. Experimental and theoretical analyses led to the identification of two key intermediates en route to DHPs and the explanation of the observed regioisomeric ratios. 1,2-DHPs show blue-cyan fluorescence in MeOH with the quantum yield Φ = 0.10-0.22 relative to quinine sulfate Φ = 0.58 and 1,4-DHPs show blue-violet fluorescence with Φ = 0.09-0.81.

Copper-Promoted One-Pot Sandmeyer-Type Reaction for the Synthesis of N-Aryltriazoles.

Herein, we report the copper-catalyzed one-pot Sandmeyer-type reaction of aromatic amines with triazoles to afford N-aryl-1,2,3-triazoles. Diazonium salts, formed from aromatic amines and tert-butyl nitrite in the presence of fluoroboric acid, reacted with triazoles in a copper-catalyzed Sandmeyer-type reaction. The reaction proceeded under mild conditions to afford N-aryltriazoles in moderate to good yields. This method is amenable to a wide range of aromatic amines and triazoles and shows diverse functional group tolerance. Inhibition of the reaction upon the addition of free radical scavengers suggested a radical pathway, in which the aryl radical, copper, and triazole formed a complex that underwent reductive elimination to give aryltriazole compounds; this is consistent with the mechanism underlying the Sandmeyer reaction. Thus, we demonstrate a new effective strategy for the construction of C-N bonds via Sandmeyer-type reactions and a valuable alternative approach for the synthesis of aryltriazole derivatives.

Hantzsch one-pot multicomponent synthesis of a novel series of bis(9,10-diarylhexahydroacridine-1,8-diones)

Efficient procedures have been developed for the synthesis of novel series of bis(9,10-diaryl-hexahydroacridine-1,8-diones) in which the two acridine moieties were linked to aliphatic, aromatic, or heteroaromatic spacers via ether or ester linkages. The target products were obtained in good to excellent yields via a multi-component reaction of the appropriate aromatic amine, 5,5-dimethyl-1,3-cyclohexanedione, and the corresponding bis-aldehydes. The reactions were also proceeded to give the target products in good yields via a multi-component reaction of the appropriate cyclic enamines, and the corresponding bis-aldehydes under similar conditions. Bis-alkylation of the appropriate hexahydroacridine-1,8-dione with the corresponding dihalo compound in a basic medium was also proved to be an effective strategy for the synthesis of the target products. The multi-component reaction of the aromatic amine, bis-aldehydes, and barbituric acid or 1,3-dimethylbarbituric acid, instead of 5,5-dimethyl-1,3-cyclohexanedione, afforded the corresponding Knoevenagel condensation adducts in good yield and unfortunately, the expected bis-tetrahydropyrimido[4,5-b]quinolines could not be isolated.

Point-of-Care Detection of Salivary Nitrite Based on the Surface Plasmon-Assisted Catalytic Coupling Reaction of Aromatic Amines.

Rapid quantification of nitrite (NO2−) in food, drink and body fluids is of significant importance for both food safety and point-of-care (POA) applications. However, conventional nitrite analytical methods are complicated, constrained to sample content, and time-consuming. Inspired by a nitrite-triggered surface plasmon-assisted catalysis (SPAC) reaction, a rapid point-of-care detection salivary nitrate was developed in this work. NO2− ions can trigger the rapid conversion of p-aminothiophenol (PATP) to p,p′-dimercaptozaobenzene (DMAB) on gold nanoparticles (GNPs) under light illumination, and the emerged new bands at ca. 1140, 1390, 1432 cm−1 originating from DMAB can be used to the quantification of nitrite. Meanwhile, to make the method entirely suitable for on-site fast screen or point-of-care application, the technique is needed to be further optimized. The calibration graph for nitrates was linear in the range of 1–100 µM with a correlation coefficient of 0.9579. The limit of detection was 1 µM. The facile method could lead to a further understanding of the progression and treatment of periodontitis and to guide professionals in planning on-site campaigns to effectively control periodontal diseases.

One-Pot Synthesis of Triazatriphenylene Using the Povarov Reaction.

The Povarov reaction combines aromatic amines, aldehydes, and alkynes in a single step and is regarded as an annulative π-extension reaction of aromatic amines. In this study, the Povarov reaction was investigated as an efficient tool for the synthesis of aza-polycyclic aromatic hydrocarbons via multiple π-extensions. The double Povarov reaction of 1,4-diaminobenzene yielded the 4,7-phenanthroline derivative as the major product, regardless of the steric repulsion in the product. The site selectivity mainly depended on the HOMO distribution of the intermediate rather than the steric factor. Based on these insights, a 1,5,9-triazatriphenylene derivative was synthesized via a triple Povarov reaction. The structures of the synthesized compounds were unambiguously determined by single-crystal X-ray diffraction analysis. The triazatriphenylene derivative formed a smooth and stable thin film upon vacuum vapor deposition and served as a hole-blocking material in organic light-emitting diodes.

Cascade embedding triethyltryptophanium iodide ionic liquid (TrpEt3+I−) on silicated titanomagnetite core (Fe3‐xTixO4‐SiO2@TrpEt3+I−): A novel nano organic–inorganic hybrid to prepare a library of 4‐substituted quinoline‐2‐carboxylates and 4,6‐disubstituted quinoline‐2‐carboxylates

AbstractA library of substituted quinolone‐2‐carboxylates (4,6‐disubstituted quinolone‐2‐carboxylates, 6‐substituted quinoline dialkyl‐2,4‐dicarboxylates, and 6‐substituted 4‐[2‐methoxy‐2‐oxoethyl]quinoline‐2‐methylcarboxylates) was obtained through different scopes of one‐pot and one‐step MCRs such as (a) three‐component reaction of aromatic amines, dialkyl acetylenedicarboxylates, and terminal alkenes/ketones; (b) pseudo three‐component reaction of anilines and dialkyl acetylenedicarboxylates; and (c) pseudo three‐component reaction of anilines and methyl propiolate under solvent‐free conditions at 100°C. The promoter of these annulation processes is a novel inorganic–organic core–shell that was obtained from silicated titanomagnetite, tryptophan amino acid, and ethyl iodide. The tryptophan embedded on the silicated titanomagnetite core (Fe3‐xTixO4‐SiO2) followed by alkylation with ethyl iodide subsequently result in in situ preparation of triethyltryptophanium iodide ionic liquid (TrpEt3+I−). The final nanohybrid (Fe3‐xTixO4‐SiO2@TrpEt3+I−) was characterized by field‐emission scanning electron microscope, EDAX, FT‐IR, TGA/DTG, vibrating sample magnetometer, and X‐ray fluorescence techniques. The highlighted features of the protocol are as follows: (a) synthesis of a vast range of substituted quinolines through a straightforward method from simple substrates under solvent‐free conditions, (b) utilizing various scopes of functionalities as substrates, (c) simple separation of the nano promoter via an external magnet, (d) regioselectivity in the cascade annulation procedure, and (e) recovery and reusability of the nanocomposite within three runs without significant activity loss.

Selective electrochemical para-thiocyanation of aromatic amines under metal-, oxidant- and exogenous-electrolyte-free conditions.

An electrochemical oxidative para-C-H-thiocyanation of aromatic amines has been developed to construct thiocyanato aromatic compounds under metal-, oxidant-, and exogenous-electrolyte-free conditions in an undivided cell. The transformation is compatible with a range of primary, secondary, and tertiary amines and shows good functional group tolerance. This approach provides an economical and environmentally benign way for para-thiocyanation of aromatic amines.

Three-component reactions of aromatic amines, 1,3-dicarbonyl compounds, and α-bromoacetaldehyde acetal to access N-(hetero)aryl-4,5-unsubstituted pyrroles.

N-(Hetero)aryl-4,5-unsubstituted pyrroles were synthesized from (hetero)arylamines, 1,3-dicarbonyl compounds, and α-bromoacetaldehyde acetal by using aluminum(III) chloride as a Lewis acid catalyst through [1 + 2 + 2] annulation. This new versatile methodology provides a wide scope for the synthesis of different functional N-(hetero)aryl-4,5-unsubstituted pyrrole scaffolds, which can be further derived to access multisubstituted pyrrole-3-carboxamides. In the presence of 1.2 equiv of KI, a polysubstituted pyrazolo[3,4-b]pyridine derivative was also successfully synthesized.

Synthesis of Green/Blue Light Emitting Quinolines by Aza-D-A Reaction Using InCl3 Catalyst.

An efficient InCl3-catalyzed sequential reaction of aromatic amines, aromatic aldehydes and functionalized alkynes leading to the formation of new quinoline derivatives exhibiting significant fluorescence activities is described. The photophysical investigations of quinolines were carried out by absorption and photoluminescence measurements. One particular compound 4 h having maximum intensity, emitting green colour (Φ = 0.78) with average life time of 6.20 ns was the best amongst the tested compounds. The presence of the amino group at the 4-aryl substituent of the quinoline backbone played an important role in executing the Povarov cyclization successfully and enhancing the flourescence properties of the newly synthesized quinolines.Supplementary InformationThe online version contains supplementary material available at 10.1007/s10895-020-02647-3.

Experimental and Computational Studies of Microwave-Assisted, Facile Ring Opening of Epoxide with Less Reactive Aromatic Amines in Nitromethane.

Nucleophilic ring opening reactions of epoxides with aromatic amines are in the forefront of the synthetic organic chemistry research to build new bioactive scaffolds. Here, convenient, green, and highly efficient regioselective ring opening reactions of sterically hindered (2R,3S)-3-(N-Boc-amino)-1-oxirane-4-phenylbutane with various poorly reactive aromatic amines are accomplished under microwave irradiation in nitromethane. All the reactions effectively implemented for various aromatic amines involve the reuse of nitromethane that supports its dual role as a solvent and catalyst. The corresponding new β-alcohol analogs of hydroxyethylamine (HEA) are isolated in 41–98% yields. The reactions proceed under mild conditions for a broad range of less reactive and sterically hindered aromatic amines. Proton NMR experiments suggest that the nucleophilicity of amines is influenced by nitromethane, which is substantiated by the extensive computational studies. Overall, this methodology elucidates the first-time use of nitromethane as a solvent for the ring opening reactions under microwave conditions involving an equimolar ratio of epoxide and aromatic amine without any catalyst, facile ring opening of complex epoxide by less reactive aromatic amines, low reaction time, less energy consumption, recycling of the solvent, and simple workup procedures.