Reaction Of Various Amines Research Articles

Homogeneous Catalysis in N-Formylation/N-Methylation Utilizing Carbon Dioxide as the C1 Source.

The growing emphasis on sustainable chemistry has driven research into utilizing carbon dioxide (CO2) as a nontoxic, abundant, and cost-effective C1 building block. CO2 offers a promising avenue for direct conversion into valuable chemicals ranging from fuels to pharmaceuticals. This review focuses on the utilization of CO2 for reductive N-formylation/N-methylation reactions of various amines, providing advantages over conventional methods involving toxic CO and other methylating reagents. The approach employs readily available reductants such as silane, borane reagents, and hydrogen (H2). The discussion encompasses recent developments in transition metal and organocatalyst systems for these reactions, highlighting mechanistic interpretations and factors influencing product selectivity.

Novel 2-Acetamido-2-ylidene-4-imidazole Derivatives (El-Saghier Reaction): Green Synthesis, Biological Assessment, and Molecular Docking.

El-Saghier reaction is the novel, general, and green reaction of various amines with ethyl cyanoacetate and ethyl glycinate hydrochloride. A new series of imidazolidin-4-ones and bis-N-(alkyl/aryl) imidazolidin-4-ones was synthesized in a sequential, one-pot procedure under neat conditions for 2 h at 70 °C. Excellent high yields (90-98%) were achieved in a short period of time while avoiding issues related to the hazardous solvents utilized (cost, safety, and pollution). The spectrum analyses and elemental data of the newly synthesized compounds helped us to clarify their structures. The obtained compounds were tested for antibacterial activity in vitro and compared to the standard antibiotic chloramphenicol as the standard, measuring the inhibition zone (nm) and activity index (%). With an antibacterial percentage value of 80.0 against Escherichia coli, N,N'-(propane-1,3-diyl) bis(2-(4-oxo-4,5-dihydro-1H-imidazole-2-yl) acetamide) proved to be the most effective. Antimicrobial activity was confirmed by a molecular docking investigation to investigate how chemicals bind to the bacterial FabH-CoA complex in E. coli (PDB ID: 1HNJ).

One-Pot Synthesis of Dihydroxyindeno[1,2-d]Imidazoles and Naphthoquinone Substituted Indandione and Oxindole Derivatives

A series of potentially bioactive compounds having either indole or indene frameworks such as dihydroindenone and indolinone derivatives were synthesized in good to high yields by one-pot, multi-component reaction of various amines, trichloroacetonitrile, ninhydrin or isatin, and 2-hydroxy-1,4-naphthoquinone. The present method offers desirable advantages including mild conditions, absence of catalyst, simple workup procedure, and easy purification process with no chromatographic technique.

Biowaste-derived hydrochar microspheres: Realizing metal-free visible-light photocatalytic oxidation of amines

Metal-free carbon photocatalysts hold great promise in future visible-light-driven selective photocatalytic organic synthesis. However, designing ideal carbon photocatalysts from sustainable strategies to further improve the photo-efficiency and economic nature is crucial for portable industrial applications. Herein, a clean and economic strategy to fabricate hydrochar microspheres as the first metal-free biochar potocatalysts is reported by a facile hydrothermal post-treatment approach from biowaste. The obtained hydrochars present excellent photocatalytic activity and reusability toward the selective oxidative coupling reactions of various amines under visible-light irradiation. Experimental studies and theoretical calculation revealed that the abundant oxygenated functional groups built-in on the surface could function as photocatalytic active sites. In particular, the diphenolic hydroxyl functional groups and quinone moieties attached to the large π-electronic-system were the main active sites involved in the photocatalytic activity. This research highlights that the utilization of sustainable biowaste-derived hydrochar materials as a low-cost and eco-environmental carbocatalysts, may open up a new avenue for light-driven diverse organic transformations.

One-pot synthesis of β-amino carbonyl compounds under solvent free condition by using alum doped nanopolyaniline catalyst

Alum doped nanopolyaniline (NDPANI), an efficient and reusable green catalyst for synthesis of β-amino carbonyl compounds has been developed. Mannich type reaction of various amines, aldehydes and ketones is carried out to synthesize the desire β-amino carbonyl compounds with excellent yield under solvent free condition. The advantages of this catalyst are inexpensive, reusability, easy preparation and stable. The reaction condition represents an advanced over established method in terms of avoiding solvent, mild reaction condition, clean reaction profile and simple workup.

Catalytic Application of Ceric Ammonium Nitrate-Stabilized Maghemite Nanoparticles (CAN-γ-Fe2O3) for Ultrasound Assisted Synthesis of β-Amino Derivatives

Owing to their inherent features like smaller size and higher surface area exposed to reactants, iron oxide nanoparticles have gained enormous interest and are extensively used as magnetically recyclable catalysts for various organic reactions. Herein, we report highly hydrophilic, non-aggregated, and strongly positively charged (ζ potential: + 45.7 mV) ultra-small cerium cations/complexes- stabilized maghemite nanoparticles in water as an efficient and reusable nanoscaled catalyst for the nucleophilic addition reaction of various amines with α,β-unsaturated carbonyl compounds to give corresponding β-amino derivatives under ultrasonic irradiation. The developed protocol provides several merits such as high product yields, mild reaction conditions, reusable catalyst and easy workup.

A Remarkably Efficient Phase-Transfer Catalyzed Amination of α-Bromo-α, β-Unsaturated Ketones in Water

Tandem conjugate addition–alkylation reaction of various amines with α-bromo-α, β-unsaturated ketones resulted in near-quantitative conversions into the corresponding aziridines when the reaction was carried out in the presence of 10 mol% of phase-transfer, PT catalysts in water. Some chiral quaternary ammonium salts derived from Cinchona alkaloids were investigated as water-stable PT catalysts. The scope and limitations of the reaction have also been investigated. The catalytic performances were significantly improved in comparison with the corresponding ordinary quaternary ammonium salt catalysts, and excellent yields (81%–96%) were obtained. Although an increase in the rate of aziridination has been accomplished, no stereoselectivity was observed. The positive values of the protocol have been confirmed.

An efficient protocol for the synthesis of oxazine derivatives using a carbocatalyst in aqueous medium

Reduced graphene oxide (rGO) is a suitable alternative to toxic metal-based catalysts, due to its large surface area, sp2 carbon backbone and oxygen functionalities that can interact with organic moieties and disperse in water. We have reported herein the synthesis of 1,3-oxazines via multicomponent reaction of various amines, formaldehyde and sesamol/2-hydroxy-1,4-naphthaquinone/6-hydroxyquinoline in aqueous medium for the first time using rGO as the catalyst at 80 °C. The reactions were complete in 5–15 min and afforded the products in excellent yields. Short reaction time, easy separation of recyclable catalyst and green methodology are advantages of this protocol.

Microwave-mediated synthesis of silver nanoparticles on various metal-alginate composites: evaluation of catalytic activity and thermal stability of the composites in solvent-free acylation reaction of amine and alcohols

This work demostratres the synthesis of different metal (Ca, Zn, Ni and Cu) alginate-supported silver nanoparticles (Agnp-MA, M and A for metal and alginate respectively) by using microwave irradiation process. The characterization of these composites has been carried out through UV–vis spectra, XRD, HRTEM and FESEM analysis which confirms the formation of spherical and crystalline nanoparticles in all MA supports with particles size range of 5–8 nm. All MAs show excellent reducing and stabilizing capabilities towards Agnp and act as support for nanoparticles too. The catalytic activities of all Agnp-MAs are tested in acylation reactions of various amines and alcohols in solvent-free medium using acetic acid as green acylating agent. The detail ionic mechanism of acylation reaction has been demonstrated. Thermal stability of all catalysts was investigated through TGA analysis and the reusability of the catalysts in a reaction is explained in terms of their thermal stability. The order of stability is Agnp-CaA > Agnp-ZnA > Agnp-NiA > Agnp-CuA. Consequently, Agnp-CaA shows best reusability property than other Agnp-MAs in the reaction and can perform well up to 5th run. Heterogeneous kinetic models are proposed for the reaction.

Multi-component synthesis of piperidines and dihydropyrrol-2-one derivatives catalyzed by a dual-functional ionic liquid

N,N,N’, N’-tetramethyl- N,N’-bis(sulfo)ethane-1,2-diaminium mesylate ([TMBSED][OMs]2) was employed for the synthesis of piperidines and dihydropyrrol-2-ones via one-pot multi-component reactions in simple and green processes. This pseudo five-component reaction of aromatic aldehydes, anilines and alkyl acetoacetates was carried out under reflux conditions in ethanol to afford substituted piperidines. Also, dihydropyrrol-2-one derivatives were synthesized by means of four-component reactions of various amines, dialkyl acetylenedicarboxylates and formaldehyde in ethanol at room temperature. The present approaches have several advantages such as good yields, easy work-ups, short reaction times, and utilize mild and clean reaction conditions.

One‐pot three‐component synthesis of novel 2‐(3‐nitro‐phenyl)‐quinazoline‐4‐carboxylic acid derivatives

AbstractA simple and easy synthesis of 2‐(3‐nitro‐phenyl)‐quinazoline‐4‐carboxylic acid (3) has been successfully developed through a one‐pot three‐component condensation reaction of (2‐amino‐phenyl)‐oxo‐acetic acid sodium salt (1) obtained from the hydrolysis of isatin with ammonium acetate and 3‐nitrobenzaldehyde. Some novel quinazoline‐ester derivatives 4‐7 were then obtained by the reaction between the new compound 3 and various alcohols. Then, quinazoline‐amide derivatives 10‐14 were synthesized from the reaction of various amines and 2‐(3‐nitro‐phenyl)‐quinazoline‐4‐carbonyl chloride (8), obtained by the reaction of compound 3 with SOCl2. Finally, some novel quinazoline‐azo derivatives 17‐19 were synthesized by the coupling reaction between β‐dicarbonyl compounds and the novel amino‐quinazoline derivative compound 15, obtained by reduction of nitro‐quinazoline derivative compound 11. Thus, a new series of quinazoline‐4‐carboxylic acid, ester, amide, and azo derivatives was synthesized and fully characterized by 1H NMR, 13C NMR, IR, and mass spectrometry analysis.

Heavy metal removing by modified bentonite and study of catalytic activity

Due to the high hydrophobicity and surface area, clays are efficient adsorbents for the removal of liquid impurities and purification of gases when they are modified. In this work, bentonite was modified with imidazole and imidazolium groups and resulting clays were characterized by different techniques such as 1H NMR, 13C NMR, TEM, SEM, XPS, TG, and FT-IR. Applications of these clays were studied in the removal of Co, Cu, and Pb in the wastewater. Effects of contact time, pH, initial heavy metal ions concentration, and kinetic were investigated. The catalytic activity of the metals adsorbed by imidazole modified bentonite was studied in A3 coupling reactions of various amines, aldehydes, and alkynes.

Rapid and catalyst free synthesis of new bis(benzo[g]chromene) and bis(pyrano[3,2-c]chromene) derivatives and optimization of reaction conditions using response surface methodology.

4,4′-(1,4-phenylene)bis(2-(alkylamino)-3-nitro-4H-benzo[g]chromene-5,10-dione) and 4,4′-(1,4-phenylene)bis(2-(alkylamino)-3-nitropyrano[3,2-c]chromen-5(4H)-one) derivatives are synthesized by a one-pot, multi-component reaction of N-alkyl-1-(methylthio)-2-nitroethenamine (derived from the reaction of various amines and 1,1-bis(methylthio)-2-nitroethene) with terephthalaldehyde or isophthalaldehyde, and 2-hydroxy-1,4-naphthoquinone or 4-hydroxycoumarin in EtOH/H2O (85 : 15) as the solvent at 89 °C. Response surface methodology (RSM) is used to investigate the effect of reaction temperature and water content of aqueous ethanol on the product yields and reaction time. The notable features of this work are the optimization of reaction conditions with minimal experiments, absence of catalyst, good yields, simple work-up and the non-chromatographic purification of products.

New class of diethyl substituted phosphoramidimidates and phosphonimidates: synthesis, spectral characterization and antimicrobial activity

A series of new class of diethyl N-2-hydroxyethyl-N'-substituted phosphoramidimidates 6(a–e) and diethyl P-morpholino-N-substituted phosphonimidates 6(f–j) was synthesized. The precursor intermediates, diethyl substituted phosphoramidites 3(a–b) were prepared initially by a reaction of various amines 1(a–b) and diethyl phosphorochloridite (2) and then they were treated by in situ with aromatic/alkyl azides through Staudinger reaction to accomplish title products. Structures of all the synthesized compounds were characterized by spectroscopic data such as IR, NMR (1H, 13C, 31P), mass, and elemental analyses. The synthesized compounds were screened for their in vitro antimicrobial activity to understand their biological potency. The biological screening results disclosed that compounds 6b, 6c, 6e, 6g, 6h and 6j having potent antimicrobial activity against all the tested pathogens.

Sulfated polyborate-catalyzed N-formylation of amines: a rapid, green and efficient protocol

A rapid, green and efficient method for N-formylation reaction of various amines with formic acid in the presence of sulfated polyborate catalyst under solvent-free conditions has been described. The catalyst has the advantage of mild Bronsted as well as Lewis acid character. The catalyst is recyclable with no significant loss in catalytic activity. The present protocol is advantageous due to its solvent-free condition, short reaction time, high yields, easy workup and ability to tolerate a variety of functional groups.

A facile synthesis of sulfonylureas via water assisted preparation of carbamates.

A novel and simple approach to the synthesis of sulfonylureas has been reported. It involved the reaction of various amines with diphenyl carbonate to yield the corresponding carbamates, which subsequently reacted with different sulphonamides to produce different sulfonylureas in excellent yields. The first reaction of diphenyl carbonate with amines was carried out in aqueous : organic (H2O : THF, 90 : 10) medium at room temperature to produce carbamates that paved a straightforward route to sulfonylureas after reaction with sulfonamides. The above process avoided traditional multistep protocols and the use of hazardous, irritant, toxic and moisture sensitive reagents such as phosgene, isocyanates and/or chloroformates.

Modulating the Photocatalytic Activity of Graphene Quantum Dots via Atomic Tailoring for Highly Enhanced Photocatalysis under Visible Light

Precise control over doping of photocatalysts is required to modulate their photocatalytic activity in visible light‐driven reactions. Here, a single precursor‐employing bottom‐up approach is developed to produce different heteroatom‐doped graphene quantum dots (GQDs) with unique photocatalytic activities. The solvothermal reaction of a norepinephrine precursor with redox active and condensable moieties effectively produces both nitrogen/sulfur codoped GQDs (NS‐GQDs) and nitrogen‐doped GQDs (N‐GQDs) by simply varying solvents (from dimethyl sulfoxide to water) under microwave irradiation. As‐prepared NS‐GQDs and N‐GQDs show similar lateral sizes (3–4 nm) and heights (1–2 nm), but they include different dopant types and doping constitution and content, which lead to changes in photocatalytic activity in aerobic oxidative coupling reactions of various amines. NS‐GQDs exhibit much higher photocatalytic activity in reactions under visible light than N‐GQDs and oxygen‐doped GQDs (O‐GQDs). The mechanism responsible for the outstanding photocatalytic activity of NS‐GQDs in visible light‐driven oxidative coupling reactions of amines is also fully investigated.

Catalytic Chan–Lam coupling using a ‘tube-in-tube’ reactor to deliver molecular oxygen as an oxidant

A flow system to perform Chan–Lam coupling reactions of various amines and arylboronic acids has been realised employing molecular oxygen as an oxidant for the re-oxidation of the copper catalyst enabling a catalytic process. A tube-in-tube gas reactor has been used to simplify the delivery of the oxygen accelerating the optimisation phase and allowing easy access to elevated pressures. A small exemplification library of heteroaromatic products has been prepared and the process has been shown to be robust over extended reaction times.

Visible-Light-Driven Oxidative Coupling Reactions of Amines by Photoactive WS2 Nanosheets

Visible-light-driven photocatalysis has been emerging as an efficient and sustainable approach for chemical transformation in organic reactions, in which photostable and cost-effective photosensitizers are required to trigger and promote it. Monolayer WS2 nanosheets smaller than 120 nm were prepared by means of a modified liquid exfoliation method, and they showed strong photoluminescence in the visible range of the electromagnetic spectrum from 450 to 650 nm. These photoactive WS2 nanosheets were exploited as photocatalysts in the oxidative coupling reactions of various amines under visible-light irradiation. They showed excellent photocatalytic activity and reusability without the loss of their catalytic activity in the visible-light-driven oxidative coupling reactions of various amines. In addition, the mechanism responsible for WS2 nanosheet catalyzed imine production under visible-light irradiation was fully investigated.

Reusable Polystyrene-Functionalized Basic Ionic Liquids as Catalysts for Carboxylation of Amines to Disubstituted Ureas

A series of polystyrene (PS)-functionalized basic ionic liquids (BILs) were prepared and used as catalysts for synthesis of disubstituted ureas (DSUs) from amines and carbon dioxide (CO2). The PS-BILs as prepared were characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared (FT-IR) spectroscopy. For investigating the catalytic activities, all PS-BILs were tested in a model reaction of cyclohexylamine (CHA) and CO2 to synthesize dicyclohexylurea (DCU). Poly-2 having branched [bis-imidazolium]/[bis-bicarbonate] was found to show the highest activity for the DCU formation among all PS-BILs catalysts. For a comparison point of view, ceria (CeO2) as a typical catalyst and original Merrifield’s resin (MR) was also applied for the reaction. Reaction conditions were optimized by varying reaction temperature, pressure, reaction time, and amount of catalyst used. Under optimized conditions, reactions of various amines with CO2 to synthesize the corr...