Oxidative Amidation Reaction Research Articles

Efficient Synthesis of N‐Pyridinylamides Using a Bimetallic Co/Fe‐Metal‐Organic Framework Heterogeneous Catalyst

AbstractThe synthesis of N‐pyridinylamides has been realized by particularly efficient technologies via bimetallic organic (Co/Fe‐MOF) catalyzed oxidative amidation between 2‐aminopyridine and benzaldehyde. The C−N bond was formed with the presence of a catalyst (Co/Fe‐MOF) as a Lewis acid and the oxidant as DTBP. The oxidative amidation reaction was conducted in 1,4‐dioxane at 120 °C with a wide range of substrates producing the corresponding amide products in good to 94 % yields. Experimental results illustrated that This accessibly offers a significant improvement over the earlier successful attempts in forming N‐pyridinyl amides. The Co/Fe‐MOF material was synthesized by solvothermal methods with the salt mixture of Fe(NO3)3.9H2O and Co(NO3)2.6H2O. The material was determined by modern analytic methods like X‐ray diffraction (XRD), Fourier‐transform Infrared spectroscopy (FT‐IR), Scanning Electron Microscope (SEM), and N2 adsorption/desorption isotherms.

Copper(II)-\u03b2-cyclodextrin immobilized on graphitic carbon nitride nanosheets as a highly effective catalyst for tandem oxidative amidation of benzylic alcohols

In this study, an efficient catalyst based on graphitic carbon nitride nanosheets (CN) and copper(II) supported β-cyclodextrin (β-CD/Cu(II)) was synthesized and used for tandem oxidative amidation of benzylic alcohols. In this regard, CN was functionalized by β-CD/Cu(II) via 1,3-dibromopropane linker (CN-Pr-β-CD/Cu(II)). The prepared catalyst was characterized using FT-IR, XRD, FE-SEM, EDS, TGA, ICP-OES, BET, and TEM analyses. CN-Pr-β-CD/Cu(II) was subsequently applied in a direct oxidative amidation reaction and it was observed that different benzyl alcohols were converted to desire amides with good to excellent efficiency. This reaction was performed in the presence of amine hydrochloride salts, tert-butyl hydroperoxide (TBHP), and Ca2CO3 in acetonitrile (CH3CN) under nitrogen atmosphere. CN-Pr-β-CD/Cu(II) can be recycled and reused five times without significant reduction in reaction efficiency.

Solvent- and additive-free oxidative amidation of aldehydes using a recyclable oxoammonium salt.

A range of acyl azoles have been prepared from aromatic, heteroaromatic, and aliphatic aldehydes by means of an oxidative amidation reaction. The methodology employs a substoichiometric quantity of an oxoammonium salt as the oxidant. It avoids the need for additives such as a base, is run solvent-free, and the oxoammonium salt is recyclable.

Employing lipase of candida antarctica (calb) as catalyst in the acetylation of para-aminophenol in aqueous and water-free medium

Candida antarctica lipase B (CaLB) is one of lipase classes enzymes that has many advantages to be used in the process of synthesizing organic compounds. In this study, some experiments were conducted to examine the ability of CaLB as a catalyst in the para-aminophenol (PAP) acetylation to produce paracetamol as the result. Two types of research have been carried out, the first one is to utilize CaLB to catalyze acetylation of PAP in a water-free reaction medium, and the second one is to use CaLB as catalyst in aqueous medium through oxidative amidation reaction. Reaction in water free system was held in ethyl catalyst acetate as solvent that also act as the acyl donor, while in the aqueous medium, acetylacetone was used as acyl donor and ethyl acetate as source to produce peracid that will be used as oxidator. Analysis was done by HPLC and TLC densitometric to follow the amount of paracetamol produced. The results of CaLB-catalyzed acylation in water free system showed that the enzyme could accept PAF and ethyl acetate as a substrate in a nucleophilic substitution reaction, resulting in paracetamol as a product. However, the yield from the acylation of PAP is still not satisfactory. In the reaction in aqueous medium, CaLB has been proven to show its activity to catalyze the acylation of PAP with acetylacetone, as well as the reaction of peracid formation from ethyl acetate. The results show that this strategy can work well and give better yields than the other reaction in water-free medium.

Fluorinated solvent-assisted photocatalytic aerobic oxidative amidation of alcohols via visible-light-mediated HKUST-1/Cs-POMoW catalysis

Successful synthesis and characterization of HKUST-1/Cs-POMoW binary composite, and application in the photocatalytic aerobic oxidative amidation reaction of alcohols under light illuminating in the visible region.

Tandem oxidative amidation of alcohols catalyzed by copper modified well-ordered mesoporous graphitic carbon nitride

A novel and efficient protocol for tandem oxidative amidation of alcohols to amides with copper modified well-ordered mesoporous graphitic carbon nitride (Cu/g-C3N4) as a highly beneficial heterogeneous catalyst has been introduced. The conversion of substituted benzyl alcohols to various amides can be efficiently carried out with amine hydrochloride salts via one-pot direct oxidative amidation reaction using tert-butyl hydroperoxide (TBHP) as a green oxidant in acetonitrile. The desired amides were afforded with high to moderate yields and the excellent yield of the corresponding amides (93%) was obtained in the presence of 20 mg of Cu/g-C3N4 at 80 °C under N2 atmosphere for about 4 h. Notably, the one-pot tandem reaction have several outstanding advantages including facile synthetic method, excellent activity, acceptable reusability, eco-friendly nature and simple work-up. The Cu/g-C3N4 was prepared through a simple procedure and characterized by FT-IR, XRD, EDS, UV–vis, DRS, FE-SEM, ICP-OES, N2 adsorption spectroscopy. It is noteworthy that, the oxidative amidation of alcohols was progressed with only 4.36 wt% of copper species on the surface of graphitic carbon nitride.

Ultrasonic Synthesis and Characterization of 2D and 3D Metal-Organic Frameworks and Their Application in the Oxidative Amidation Reaction.

Ultrasound irradiation as an environmentally friendly and inexpensive method successfully applied for the synthesis of two-dimensional (2D) and three-dimensional (3D) metal–organic frameworks (MOFs). Sonochemically synthesized AM-Co1 and AM-Co2 powder has been employed as a green heterogeneous catalyst for the oxidative amidation reaction. The results show that AM-Co1 with a two-dimensional (2D) structure can act as an excellent catalyst for this reaction under ultrasonic irradiation compared to AM-Co2 with a three-dimensional (3D) structure. According to green principles, we used water as a green solvent and air as an oxidant for the oxidative amidation reaction. A wide variety of aldehydes and amines have been used for the synthesis of amides in good to excellent yields (75–90%). Also, the MOF catalyst could be recovered and reused several times without loss of activity.

DNA-Compatible Copper-Catalyzed Oxidative Amidation of Aldehydes with Non-Nucleophilic Arylamines.

We report a DNA-compatible protocol for synthesizing amides from DNA-bound aldehydes and non-nucleophilic arylamines including aza-substituted anilines, 2-aminobenzimidazoles, and 3-aminopyrazoles. The reactions were carried out at room temperature and provided reasonable conversions and wide functional group compatibility. The reactions were also successful when employing aryl and aliphatic aldehydes. In addition, qPCR and NGS data suggested no negative impact on DNA integrity after the copper-mediated oxidative amidation reaction.

Oxidative amidation by Cu(ii)–guanidine acetic acid immobilized on magnetized sawdust with eggshell as a natural base

Copper(ii)–guanidine acetic acid complex was immobilized on the surface of magnetized raw waste sawdust (SD) as an abundant natural biopolymer and employed as an efficient and recoverable catalyst in oxidative amidation reaction, while waste eggshell (ES) powder was used as a low-cost solid base.

Magnetically recyclable palladium nanoparticles (Fe3O4‐Pd) for oxidative coupling between amides and olefins at room temperature

A convenient method for the synthesis of magnetically recyclable palladium nanoparticles (Fe3O4‐Pd) is described. The catalytic application of the Fe3O4‐Pd nanoparticles was explored for the first time in oxidative coupling between amides and olefins. p‐Toluenesulfonic acid plays a significant role in the oxidative amidation reaction. The reaction proceeds at room temperature, resulting in (Z)‐enamides under ambient air in the absence of co‐catalyst and ligand. The superparamagnetic nature of Fe3O4‐Pd facilitates easy, quantitative recovery of the catalyst from a reaction mixture, and it can be reused for up to three consecutive cycles with a slight decrease in catalytic activity.

Appraisal of Ruthenium(II) complexes of (4-phenoxyphenylazo) ligands for the synthesis of primary amides by dint of hydroxylamine hydrochloride and aldehydes

A new family of O, N donor-functionalized (4-phenoxyphenylazo)-2-naphthol/4-substituted phenol-based ligands (HL1-HL4) has been synthesized. The prepared ligands were successfully utilized for the access of a series of ruthenium(II) carbonyl complexes of the type [Ru(L)Cl(CO)(EPh3)3] (E = phosphine/arsine), (L = 1-(4-phenoxyphenylazo)-2-naphthol (HL1), 2-(4-phenoxyphenylazo)-4-chlorophenol (HL2), 2-(4-phenoxyphenylazo)-4-methylphenol (HL3) and 2-(4-phenoxyphenylazo)-4-methoxyphenol (HL4)). All of the ruthenium(II) carbonyl complexes and ligands have been fully characterized by FT-IR, UV–visible, 1H NMR, 31P NMR, mass spectrometry and CHN analysis. The ligands have been analyzed by 13C NMR. The UV–visible spectroscopic study reveals that both the ligands and Ru(II) complexes exhibit excellent charge transfer transitions. This is the basic criteria for the oxidative amidation reaction, which is an influential strategy for the transformation of oxygenated organic compounds to the profitable amides. However, this catalytic process makes more impact on the application of new divalent ruthenium(II) azo compounds as catalyst in a single-pot conversion of aldehydes to amides in the presence of NaHCO3.

Oxidative amidation of benzyl alcohol, benzaldhyde, benzoic acid styrene and phenyl acetylene catalyzed by ordered mesoporous HKUST‐1‐Cu: Effect of surface area on oxidative amidation reaction

HKUST‐1‐Cu synthesized in the presence and absence of P‐123 trough solvotermal method. After characterization using some different microscopic and spectroscopic techniques such as XRD, FT‐IR, SEM, ICP, BET and TEM its catalytic activity was investigated in the oxidative coupling of benzyl alcohol, benzaldhyde, benzoic acid, styrene and phenyl acetylene with N,N‐dialkylformamides for the preparation of N,N‐dimethylformamides. Different derivatives of tertiary amides were synthesized in moderate to good yields in the presence of just ~0.28 mol% of this catalytic system. Reusability of the synthesized catalysts was examined and catalysts were reusable for 8 times without significant decrease in optimized conditions.

CuI incorporated cobalt ferrite nanoparticles as a magnetically separable catalyst for oxidative amidation reaction.

A Cu-incorporated magnetic nanocatalyst (CoFe2O4@SiO2-SH-CuI) has been developed by immobilizing CuI on the modified surface of CoFe2O4 magnetic nanoparticles. The surface of the silica coated cobalt ferrite magnetic core was first treated with 3-mercaptopropyl triethoxysilane to produce the thiol functionalized nanoparticle CoFe2O4@SiO2-SH. Further treatment of the nanoparticle with CuI produced the desired magnetic nanocatalyst. The versatility of the catalyst has been demonstrated for the synthesis of N-(pyridin-2-yl) benzamide via oxidative amidation of aryl aldehydes with 2-amino pyridine in the presence of an oxidant. The reaction was carried out in DMSO at 80 °C using TBHP (70% aqueous) in the presence of 20 wt% of the catalyst. Notably, the catalyst could be separated from the reaction mixture in the presence of an external magnetic field. During the study, a new compound N-(pyridin-2-yl)anthracene-2-carboxamide has been synthesized and its turn on fluorescence sensing properties towards various metal ions have been studied. Fluorescence experiments and theoretical studies indicated that the newly synthesized carboxamide molecule can be used for fluorescence sensing of the Hg2+ ion in aqueous solution.

Iodine‐Catalyzed Formation of Amide Bond: Efficient Strategy for the Synthesis of Aromatic Primary Amides

AbstractA practical and efficient methodology for the synthesis of aromatic primary amides by reaction of benzylic alcohols and aqueous ammonia in the presence of an I2/TBHP system in acetonitrile was developed. This oxidative amidation proceeded smoothly at ambient temperature and tolerated a variety of functional groups. A wide range of aromatic primary amides were obtained in moderate to high yields. Preliminary kinetic studies and a possible mechanism of the oxidative amidation reaction were also discussed.

Rhodium-Catalyzed Oxidative Amidation of Sterically Hindered Aldehydes and Alcohols

A rhodium-catalyzed oxidative amidation reaction has been developed with sterically hindered aldehydes and alcohols for the synthesis of amides containing a quaternary carbon at the α position. A variety of amine nucleophiles, both aliphatic and aromatic, are employed and afford the corresponding amides in good to excellent yields. Finally, mechanistic studies are performed to gain insight into both catalytic cycles.

ChemInform Abstract: Cobalt‐Catalyzed Dehydrogenative Coupling of Alcohols/Aldehydes and Amines: An Important Role for Imine Hydration.

AbstractA cobalt and iodide co‐catalyzed oxidative amidation reaction between alcohols or aldehydes and amines smoothly proceeds under mild conditions affording amides with broad functional group tolerance.

Copper(I)-catalysed amidation and successive oxidation of benzylic C(sp3)–H bond: synthesis of 1H-pyrrolo[3,4-b]quinoline-1,3(2H)-diones

An efficient copper(I)-catalysed intramolecular arylmethyl C(sp3)–H direct oxidative amidation reaction has been developed for the preparation of drug-like 1H-pyrrolo[3,4-b]quinoline-1,3(2H)-diones from readily available 2-methyl-3-carbamoyl-quinolines.

ChemInform Abstract: Metal Free Synthesis of α‐Keto Amides from 2‐Hydroxy Acetophenones Through Domino Alcohol Oxidation—Oxidative Amidation Reaction.

AbstractAn economic and environment friendly IBX promoted synthesis of α‐keto amides from α‐oxoalcohols and amines through domino alcohol oxidation—oxidative amidation reaction sequence under metal‐free conditions is reported.

Cobalt‐Catalyzed Dehydrogenative Coupling of Alcohols/Aldehydes and Amines: An Important Role for Imine Hydration

AbstractA cobalt and iodide co‐catalyzed oxidative amidation reaction between alcohols or aldehydes and amines has been developed. The reactions proceeded smoothly under mild conditions using tert‐butyl hydroperoxide solution in water as the terminal oxidant, with broad functional group tolerance. Mechanistic studies indicated that the tBuO⋅/tBuOO⋅ radical generated in situ is the active species responsible for hydrogen abstraction in this catalytic process, and not IO−/IO2−/IO3− ions. Investigation into the reaction mechanism also revealed the potential transiency of a hemiaminal and the important role of its regeneration by imine hydration.

BODIPY catalyzed amide synthesis promoted by BHT and air under visible light.

A novel and efficient protocol for the synthesis of amides is reported which employs a BODIPY catalyzed oxidative amidation reaction between aromatic aldehydes and amines under visible light. Compared with the known Ru or Ir molecular catalysts and other organic dyes, the BODIPY catalyst showed higher reactivity toward this reaction. Mechanistic studies reveal that dioxygen could be activated through an ET and a SET pathway, forming active peroxides in situ, which are vital for the key step of the reaction, i.e. the oxidation of hemiaminal to amide. The broad substrate scope and mild reaction conditions make this reaction practically useful and environmentally friendly for the synthesis of amide compounds.