Two efficient acid-base-free procedures are introduced for the sulfenylation of cyclic enaminone compounds under aerobic and DMSO-oxidative conditions catalyzed by Na2S2O3. According to procedures, a ...mixture of an aryl thiol and a cyclic enaminone are reacting together in DMF (aerobic oxidative conditions) or DMSO in the presence of a catalytic amount of Na2S2O3 (0.1 equiv in DMSO and 0.4 equiv in DMF) to produce the related α-sulfenylated cyclic enaminone compound in high yields. Both reactions are not satisfactory in the absence of Na2S2O3, so the reaction in DMF (aerobic condition) does not produce any product at all and the conversion in DMSO progresses by less than 50% within 24 h.
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The new ligand 3,3'-(1,2-phenylenebis(azanediyl))bis(5,5-dimethylcyclohex-2-en-1-one) (L) derived from 5,5-Dimethylcyclohexane-1,3-dione with 1,2-phenylenediamine was used to prepare a new chain of ...metal complexes of Mn(ii), Co(ii), Ni(ii), Cu(ii), Cd(ii) and Zn(ii) by inclusive formula M(L)Cl2. Characterized compounds on the basis of 1H, 13CNMR (for ligand (L)), FT-IR and U.V spectrum, melting point, molar conduct, %C, %H and %N, the percentage of the metal in complexes %M, Magnetic susceptibility, thermal studies (TGA), while its corrosion inhibition for (plain steel) in tap water is studied by weight loss. These measurements proved that by (O and N) atoms in the ligand, the metal ions are coordinated in a tetra dentate form and the tetrahedral structure of these complexes is suggested. Using the pathogenic bacteria such as (Escherichia coli) (G−) and (Staphylococcus aurous) (G+) and fungi (Candida albicans) and (Trichomoniasis), the anti-microbial action of both (L) and their complexes was studied by diffusion method.
•The synthesis procedure was developed for preparing Fe3O4@SiO2NH2-TFA nanocatalysts.•Fe3O4@SiO2NH2-TFA nano-catalysts were fully characterized by TEM, XRD, FTIR, TGA, SEM-EDX, XPS, BET. and VSM.•The ...synthesized catalyst exhibits high catalytic activity for enamination of 1,3-dicabonyl compounds and amines.•The nano-catalyst can be recycled by external magnet up to 8 times with slightly loss of catalytic acitvity.•This procedure provides green, facile, time-saving, and cheap.
In this paper, a simple method is reported for the preparation of trifluoroacetic acid immobilized silica magnetite nanoparticles. It is a new magnetic nano-catalyst for β-enaminone synthesis from 1 3-dicarbonyl compound. The magnetic nano-catalyst preparation was successfully synthesized by two different methods based on continuous flow synthesis. The synthesized magnetic nano-catalysts were identified using Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), energy diffusion scanning electron microscopy (SEM-EDX). N2 adsorption isotherm, thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and vibrating sample magnetometry (VSM) to confirm chemical composition, morphology, thermal stability, and magnetization. The magnetic nano-catalyst was found active the synthesis of β-enaminones. The magnetically nano-catalytic system employs environmentally friendly, solvent-free mild reaction conditions, various β-enaminone products requiring good to excellent yield under mild reaction conditions. This β-enaminone synthesis protocol has several advantages in terms of introducing a novel magnetically nano-catalytic system based on the recovery capability of the magnetic nano-catalyst. The reusability of the magnetic nano-catalyst was also studied for 7–8 consecutive cycles without significant loss of catalytic activity.
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Complexes of enaminones; 4-N,N-diethylamine-pent-3-ene-2-one HL1, 4-N,N-di n-propylamine-pent-3-ene-2-one HL2 and 4-N,N-dicyclohexylamine-pent-3-ene-2-one HL3 with Fe(II) and Zn(II) ions were ...prepared by reacting the equimolar ethanolic solutions of the ligands (HL1, HL2 and HL3) with ethanolic metal solutions. The complexes formed, were characterized by infrared, ultraviolet and atomic absorption spectroscopy. Ligands and their metal complexes were tested against Escherichia coli and Staphylococcus aureus bacteria to assess their antibacterial action using disc diffusion method. Ligands were completely inactive against bacteria whereas the complex Zn (HL1) has significant action on both bacteria, indicating that it has a good potential as bactericide. Other complexes have normal antiseptic character.
A novel electrochemical strategy for the efficient synthesis of α,α-dihaloacetophenone derivatives from N,N-dimethyl enaminones was reported, which was performed under constant current conditions in ...a simple undivided cell using HCl or HBr as halide source and supporting electrolyte.
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We have developed a method to synthesize α,α-dihaloketones under electrochemical conditions. In this reaction, the Cl- or Br- is oxidized to Cl2 or Br2 at the anode, which undergoes two-step addition reactions with the N,N-dimethyl enaminone, and finally breaks CC of the N,N-dimethyl enaminone to generate α,α-dihaloketones. The electrosynthesis reaction can be conveniently carried out in an undivided electrolytic cell at room temperature. In addition, various functional groups are compatible with this green protocol which can be applied simultaneously to the gram scale without significantly lower yield.
Enaminones have in the past decade received renewed interest in organic synthesis by acting as highly versatile building blocks. Particularly, the featured amino and carbonyl group in the enaminone ...structure endow them with the ability of tolerating water via hydrogen bonding effect. Thus, designing synthetic methods in aqueous medium with enaminones as the main building blocks has received extensive attention and notable success. Based on our longstanding efforts and interests in enaminone chemistry, we review herein the research advances in enaminone participated organic synthesis in aqueous medium.
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•Novel enaminone derivative and four lanthanide(III) complexes with it were synthesized and characterized.•Hirschfeld surface analysis of ligand indicates the intermolecular hydrogen ...bonds and π···π-stacking.•Ligand exhibits bidentate-bridging coordination mode resulting in the formation of layered structure of lanthanide(III) compounds.•The lanthanide polyhedron is close to bicapped square antiprism.•Ligand demonstrates bright green emission with nanosecond lifetime of the excited state and quantum yield 41%.•Upon complexation, emission of europium(III) complex is red and lifetime is equal to 0.13 ms.
New enaminone derivative, 2-{(4-methoxyphenyl)aminomethylene}-5,5-dimethyl-cyclohexane-1,3-dione (HL), and lanthanide(III) compounds based on it Ln(HL)2(NO3)3n, (where Ln3+=Eu (1Eu), Sm (2Sm), Tb(3 Tb) and Dy (4Dy)) have been synthesized. The complexes have been fully characterized by spectroscopic and analytical methods including single crystal X-ray structure. To establish closer intermolecular contacts and HOMO/LUMO energy, the Hirshfeld surface analysis, as well as DFT calculations has been carried out. According to single-crystal X-ray diffraction analysis ligand exhibits bidentate-bridging mode. This leads to the formation of polymeric structure as layer, arranged parallel to ab crystallographic plane. The lanthanide polyhedron is close to bicapped square antiprism. All obtained compounds are isomorphous to each other. The study of photoluminescence showed the presence of a bright green emission of the ligand with a quantum yield of 41 %. The weak sensitization occurs only in case of europium(III) complex leading to apparent luminescence quantum yield of 0.021 %, with ∼4 % sensitization efficiency. Emission spectra of other compounds are the same to the ligand one.
Vitrimers are a new class of polymeric materials with very attractive properties, since they can be reworked to any shape while being at the same time permanently cross‐linked. As an alternative to ...the use of transesterification chemistry, we explore catalyst‐free transamination of vinylogous urethanes as an exchange reaction for vitrimers. First, a kinetic study on model compounds reveals the occurrence of transamination of vinylogous urethanes in a good temperature window without side reactions. Next, poly(vinylogous urethane) networks with a storage modulus of ≈2.4 GPa and a glass transition temperature above 80 °C are prepared by bulk polymerization of cyclohexane dimethanol bisacetoacetate, m‐xylylene diamine, and tris(2‐aminoethyl)amine. The vitrimer nature of these networks is examined by solubility, stress‐relaxation, and creep experiments. Relaxation times as short as 85 s at 170 °C are observed without making use of any catalyst. In addition, the networks are recyclable up to four times by consecutive grinding/compression molding cycles without significant mechanical or chemical degradation.
Catalyst‐free vitrimers based on the transamination of vinylogous urethanes are prepared from readily accessible chemicals. These high Tg, cross‐linked materials exhibit excellent mechanical properties, while the exchangeable bonds enable full stress‐relaxation on short time scales and recycling over many cycles.
In the present study, 12-tungestocobaltic acid, H
CoW
, was immobilized on nano silica from rice husk (CoW@NSiO
) to develop a novel, efficient, heterogeneous and recyclable nano catalyst for the ...synthesis of
-enaminones. It is apparent from acidity and cyclic voltammetric measurements that, the catalyst is electroactive and undergoes reversible redox transitions, as well as it is contains strong acid sites and mobile protons. As evidenced from mechanistic investigations, CoW@NSiO
can catalyze the synthesis of
-enaminones with two simultaneous ways: electron transfer and Brønsted acid mechanisms. In order to confirm the synthesis of enaminones through simultaneous mechanisms of electron transfer and acidity, the model reaction was carried out in the presence of K
Co as an electroactive catalyst and CoW@NSiO
with electron scavenger as an acid catalyst. The results showed that the reaction proceeded simultaneously through both mechanisms. There is evidence that the electron transfer property of this catalyst is most pronounced in this type of organic reactions. The catalyst demonstrated outstanding performance, and the methodology proved to be versatile, yielding excellent results across a wide range of substrates. It is worth mentioning that aliphatic amines were well-tolerated in the process and produced
-enaminone compounds with excellent yields and short reaction times. Also, reactions with dimedone, a cyclic 1,3-diketone, delivered moderate product yields. Additionally, the catalyst showed remarkable recyclability, maintaining its activity for a minimum of five consecutive cycles without any noticeable decline. Notably, the cyclic voltammetric and acidity measurements revealed that the catalyst’s electron transfer property and Brønsted acidity remained unchanged after five runs.
The utility of the enaminonitriles 3a and 3b for the synthesis of the pyrazole derivatives 5a,b, 7a,b, diaminopyrimidine derivatives 9, 11, pyrazolo1,5-apyrimidines 12, 15, triazolo4,3-apyrimidines ...13, 16, imidazo1,2-apyrimidine derivatives 14 and 17, was explored. Most of the synthesized compounds showed excellent in vitro antitumor activity against MCF-7 cell line. They also exhibted high antimicrobial and antioxidant activities. Density functional theory (DFT) calculations at the B3LYP/6-31G level of theory have been carried out to investigate the equilibrium geometry of the novel phenylpyrazolo1,5-apyrimidin-6-yl)methanone derivative 12 and phenylpyrazolo1,5-apyrimidine derivative 15. The structure-activity relationship (SAR) has been used to correlate the biological activity with the appropriate quantum such as total energy. The energy of the HOMO and LUMO and Mulliken atomic charges were also calculated.
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•A series of pyrazole and pyrimidine derivatives was synthesized.•The synthesized compounds exhibited potent antitumor activity.•Most of compounds showed antimicrobial and antioxidant activities.•DFT calculations of two examples of the new compounds was carried.
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