Tetraketone Derivatives Research Articles

“Green” Synthesis of Substituted Tetraketones with Prominent Bactericide Effect

Abstract: Effective and “green” synthesis of tetraketone derivatives was elaborated. The last compounds developed prominent bactericide activity against both MIC and MBC S. aureus (ATCC-6538P) bacteria. The novelty of this approach is concluded in the application of Al(OH)3 catalyst for the Knoevenagel-Michael cascade reaction of aromatic aldehydes and 1,3-cyclic diketones in water. The process is chemoselective and affords high yield of tetraketones under benign conditions. The catalyst maintained 80% of initial activity within four cycles. The proposed method can be regarded as an alternative to the existing syntheses of biologically active tetraketones that utilize homogeneous and expensive heterogeneous catalysts. result: The reaction is chemoselective and gives high yields of tetraketones under mild conditions. The catalyst maintained 80% yield until the third reuse cycle.

A biscationic imidazolium ionic liquid immobilized on graphene oxide as an efficient heterogeneous catalyst for the synthesis of tetraketone derivatives

A bisimidazolium ionic liquid supported on graphene oxide was used as a heterogeneous catalyst for the synthesis of tetraketone derivatives with high reaction yields, facile separation, short reaction time, good stability and recoverability.

The expediency of [BCMIM][Cl] ionic salt in the synthesis of tetraketones: Insights into their photophysical properties and theoretical calculations

A simple, efficient and straightforward method for the synthesis of 2,2′-phenylmethylene-bis(3‑hydroxy-5,5-dimethyl-2-cyclohexene-1-one) derivatives has been developed. Dimedone and aldehydes underwent condensation in the presence of 6 mol% [BCMIM][Cl] ionic salt in aqueous ethanol at room temperature. A total of 20 tetraketone derivatives were successfully synthesized with high yields. The synthesized derivatives were meticulously characterized using several spectral techniques. In addition, the photophysical properties of 15 selected derivatives, such as the molar extinction coefficient (ε) and Stoke's shift (Δῡ), have been calculated. These values range from 1.2788 × 104 M−1 cm−1 to 2.1202 × 104 M−1 cm−1 and 760 cm−1 to 449 cm−1, respectively. Additionally, the experimental data is validated by density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations. Investigations based on theory revealed a pattern that was consistent with the experimental results.

Bread waste in the form of CoFe2O4@TBW catalyst was used as a green biocatalyst to synthesize pyranopyrazole and tetraketone derivatives

Bread waste in the form of CoFe2O4@TBW catalyst was used as a green biocatalyst to synthesize pyranopyrazole and tetraketone derivatives

Crystallography and DFT Studies of Synthesized Tetraketones.

Two tetraketone derivatives, one previously reported and one novel, were synthesized, whose structures have been confirmed by elemental analyses, NMR, HPLC-MS, and IR spectroscopy. The crystal structures of synthesized tetraketones were determined using X-ray single-crystal diffraction. To analyze the molecular geometry and compare with experimentally obtained X-ray crystal data of synthesized compounds 1 (2,2'-((4-nitrophenyl)methylene)bis(5,5-dimethylcyclohexane-1,3-dione)) and 2 (2,2'-((4-hydroxy-3-methoxy-5-nitrophenyl)methylene)bis(5,5-dimethylcyclohexane-1,3-dione)), DFT calculations were performed with the standard 6-31G*(d), 6-31G**, and 6-31+G* basis sets. The calculated HOMO-LUMO energy gap for compound 1 was 4.60 eV and this value indicated that compound 1 is chemically more stable compared to compound 2 whose energy gap was 3.73 eV. Both compounds' calculated bond lengths and bond angles were in very good accordance to experimental values determined by X-ray single-crystal diffraction.

Enhanced catalytic activity of bio-fabricated ZnO NPs prepared by ultrasound-assisted route for the synthesis of tetraketone and benzylidenemalonitrile in hydrotropic aqueous medium

Mushroom-like mesoporous and hexagonal ZnO nanoparticles were synthesized from plant extract and chemical method respectively, by co-precipitation method in aqueous medium. Different morphological forms of ZnO NPs were characterized by XRD, TGA, FESEM, EDX, FTIR, UV–Vis and BET. Neem (Azadirachta indica) leaf extract and ultrasound irradiation have a crucial role in the formation of different morphologies of ZnO NPs. ZnO NPs synthesized from plant extract and hydrotrope show a synergistic effect that leads to efficient synthesis of benzylidenemalonitrile and tetraketone derivatives at room temperature in water. Simple preparation of the catalyst, excellent yields, reusability of catalyst with consistent activity and ease of product isolation are the most significant advantages of this green protocol.

1,8-Diazabicyclo [5.4.0] undec-7-ene functionalized cellulose nanofibers as an efficient and reusable nanocatalyst for the synthesis of tetraketones in aqueous medium

1,8-Diazabicyclo [5.4.0] undec-7-ene functionalized cellulose nanofibers (CNF@DBU[Cl]) were simply prepared and characterized by analytical techniques. Scanning electron microscope confirmed that CNF@DBU[Cl] was formed with average size of 30–60 nm. X-ray diffraction of CNF@DBU[Cl] showed that the crystalline structure of the cellulose nanofibers was remained unchanged after functionalization. According to elemental analyses and thermal gravimetric analysis, the loading amount of organic group on cellulose nanofibers was found to be 1.46 mmol/g. The catalytic activity of DBU functionalized cellulose nanofibers was studied for the synthesis of biologically important tetraketone derivatives in the reaction of aldehydes with 1,3-dicarbonyl compounds. In the presence of CNF@DBU[Cl], the corresponding tetraketones were obtained in 80–96% yields under very mild reaction conditions. The catalyst was recovered and reused four successive runs without significant loss of catalytic activity. This method showed several significant advantages including short reaction times, high yields of products, use of various substrates, convenient work-up, no necessity of extraction or chromatographic purification steps, environmentally friendly conditions and lack of use of any harmful solvent.

Extraction and complexation of lanthanide ions by dihomooxacalix[4]arene and calix[4]arene tetraketone derivatives: An experimental and molecular dynamics investigation

Lanthanide cation binding by tetraketone derivatives of p-tert -butyldihomooxacalix[4]arene (methyl 1a , tert -butyl 1b , adamantyl 1c and phenyl 1d ) and of p-tert -butylcalix[4]arene (methyl 2a , adamantyl 2c and phenyl 2d ), in the cone conformation, was investigated. These properties were assessed by extraction experiments of the metal picrates from water to dichloromethane and by stability constant measurements in acetonitrile by UV-vis absorption spectrophotometry. Proton NMR titrations with La 3+ , Eu 3+ and Yb 3+ cations were also performed to obtain information on the binding sites. Molecular dynamics (MD) simulations and potential of mean force (PMF) free energy calculations were carried out for ligands 1d and 2d in pure solvents and at a CH 2 Cl 2 /water interface to add further information on the complexation and extraction processes. Comparison between dihomooxacalix[4]arene and calix[4]arene ketone derivatives showed that the former are better extractants, displaying the highest percentages of extraction for Gd 3+ and Yb 3+ cations. Concerning complexation, all ligands studied presented high affinities for the lanthanide ions. Ligands 1b and 1d showed preference for the light La 3+ , while 2d displayed the strongest affinity for the heavy and smaller Yb 3+ . These results were also corroborated by MD simulations, which revealed specificities of ligands 1d and 2d in the binding of lanthanide cations. L'interaction entre des cations lanthanide et des dérivés tétracétone du p - tert -butyldi-/homooxacalix[4]arène (méthyl 1a , tert -butyl 1b , adamantyl 1c et phényl 1d ) et du p - tert -butylcalix[4]arène (méthyl 2a , adamantyl 2c et phényl 2d ), en conformation cône, a été étudiée. Ces propriétés ont été évaluées par des expériences d'extraction de picrates métalliques de l'eau vers le dichlorométhane et par la détermination des constantes de stabilité dans l'acétonitrile par spectrophotométrie d'absorption dans l’UV–visible. Des titrages RMN du proton avec les cations La 3+ , Eu 3+ et Yb 3+ ont également été effectués afin d'obtenir des informations sur les sites de liaison. Des simulations en dynamique moléculaire (DM) et des calculs d'énergie libre du potentiel de force moyenne (PMF) ont été réalisés avec les ligands 1d et 2d dans les solvants purs et à l'interface CH 2 Cl 2 /eau afin d'apporter des informations complémentaires sur les processus de complexation et d'extraction. La comparaison entre les dérivés cétone du dihomooxacalix[4]arène et du calix[4]arène a montré que les premiers possèdent un meilleur pouvoir extractant, avec les pourcentages d'extraction les plus élevés pour les cations Gd 3+ et Yb 3+ . Concernant la complexation, tous les ligands étudiés présentent des affinités élevées pour les ions lanthanide. Les ligands 1b et 1d montrent une préférence pour La 3+ , cation léger, alors que 2d présente la plus forte affinité pour Yb 3+ , cation lourd et moins volumineux. Ces résultats ont également été confirmés par des simulations en DM, qui ont révélé les spécificités des ligands 1d et 2d lors de leur interaction avec les cations lanthanide.

Fluorinated tetraketone derivatives of N-substituted carbazoles and their Eu(III) complexes for fluorescence immunoassay

New fluorinated tetraketone derivatives of N-substituted carbazoles were synthesized and tested as ligands for fluorescence immunoassay. The spectral properties of the obtained heterocyclic tetraketones and their Eu(III) complexes were studied. The complexes showed longwave absorption at 360–380 nm, high extinction coefficient values, long lifetime of excited states, and intense luminescence, allowing to consider the use of such lanthanide complexes in immunofluorescence analysis.

Selective and highly efficient synthesis of xanthenedione or tetraketone derivatives catalyzed by ZnO nanorod-decorated graphene oxide

A new and efficient method for the pseudo three-component synthesis of diverse tetraketone or xanthenedione derivatives has been described in the presence of ZnO nanorods decorated graphene oxide.

Nano Fe/NaY zeolite: an efficient and reusable solid-supported catalyst for synthesis of 1-oxo-hexahydroxanthene and tetraketone derivatives

Nano Fe/NaY zeolite with high loading of Fe ions was successfully synthesized by the ion-exchange technique at ambient temperature. The prepared Fe/NaY was characterized by X-ray diffraction, scanning electron microscopy, energy-dispersive X-ray spectroscopy, Brunauer–Emmett–Teller (BET) surface area measurements, and Fourier-transform infrared (FT-IR) spectroscopy. The data analyses confirm the presence of iron oxide (up to 32.8 %) with average diameter of 30–40 nm on the surface of NaY zeolite. The catalytic activity of nano Fe/NaY zeolite was examined in the preparation of 1-oxo-hexahydroxanthene and tetraketone derivatives. The results showed its applicability as a green, reusable, and promising catalyst for organic synthesis. This protocol demonstrates several notable advantages including short reaction times, environmentally friendly conditions, no necessity for extraction or chromatographic purification steps, more convenient workup, high yields of products, and lack of use of any injurious solvents. The catalyst was recovered and reused up to four consecutive times without significant loss in catalytic activity.

Nano-Fe3O4 Encapsulated-Silica Particles Bearing Sulfonic Acid Groups as a Magnetically Separable Catalyst for Highly Efficient Knoevenagel Condensation and Michael Addition Reactions of Aromatic Aldehydes with 1,3-Cyclic Diketones

Sulfonic acid-functionalized silica-coated nano-Fe3O4 particles (Fe3O4@SiO2-SO3H) have been prepared as a novel heterogeneous acid using a facile process. The material was subsequently identified as an efficient catalyst for the synthesis of a variety of tetraketone derivatives via the Knoevenagel condensation and Michael addition reactions of aromatic aldehydes to dimedone, 1,3-indanedione, and 1,3-dimethyl barbituric acid. The catalyst could be readily recovered using a simple external magnet and reused several times without any significant loss in activity. The current catalytic process is both sustainable and economical because it operates under aqueous conditions, the catalyst can be recovered and reused, and the reactions themselves require only a short time and provide the products in high yield.

Synthesis and characterization of some new tetraaldehyde and tetraketone derivatives and X-ray structure of 1,1'-(4,4'-(2-(1,3-bis(4-acetylphenoxy)propan-2-ylidene)propane-1,3-di-yl)bis(oxy)bis(4,1-phenylene))diethanone.

Tetraketone and tetraaldehyde derivatives 2a–d were synthesized via the reaction of ethene-1,1,2,2,-tetra-yl-tetramethylene tetrabromide (1) with hydroxyketone and aldehyde derivatives. The molecular structures were identifed by IR, 1H-NMR, 13C-NMR and MS analysis. The crystal structure of the title compound 2a, C38H36O8, is reported. Its crystal data are: monoclinic, space group P 2(1)/n with cell dimensions of a=9.0395(12) Å, b=12.6114(17) Å, c=13.8166(18) Å, β=95.875(3), V=1566.8(4) Å3, F.W.=620.67, ρcalc=1.316 gcm3 for Z=2, μ=0.092 mm−1

Complexation and transport of transition and heavy metal cations by p-tert-butyldihomooxacalix[4]arene tetraketones and X-ray crystal structure of the tert-butyl ketone derivative

The binding properties of three p-tert-butyldihomooxacalix[4]arene tetraketone derivatives (tert-butyl 2b, adamantyl 2c and phenyl 2d) in the cone conformation and one derivative (methyl 2a) in a partial cone conformation, towards transition (Mn2+, Fe2+, Co2+, Ni2+, Cu2+ and Zn2+) and heavy (Ag+, Cd2+, Hg2+ and Pb2+) metal cations have been established by extraction studies of metal picrates from water into dichloromethane, transport experiments with the same salts through a dichloromethane membrane and stability constant measurements in methanol and acetonitrile. Results concerning the microcalorimetric study of Cu2+, Ag+ and Pb2+ complexes in methanol are presented. The affinity of the ligands for some cations (Zn2+, Ag+, Pb2+ and Hg2+) has also been investigated by proton NMR spectrometry. The X-ray crystal structure of tert-butylketone 2b was determined. Towards transition metal cations, ketones 2b, 2c and 2d are reasonable binders, showing in general preference for Cu2+. Methylketone 2a is a poor binder for these cations, due to its partial cone conformation. The three ligands in the cone conformation present a high affinity for the heavy metal cations, with selectivities for Ag+ and Pb2+. This series of cations is even fairly well complexed by methylketone 2a, which presents high stability constants for Hg2+ and Pb2+. The cases studied by 1H NMR titrations confirm the formation of 1 : 1 complexes between the ketones and the cations, also indicating that they should be located inside the cavity defined by the phenoxy and carbonyl oxygen atoms. Ketones 2b, 2c and 2d show transport rate sequences that follow, in general, the same trends observed in extraction and complexation for transition cations, but they are reversed for the heavy metal cations.

Complexation and Transport of Alkali and Alkaline Earth Metal Cations by p-tert-Butyldihomooxacalix[4]arene Tetraketone Derivatives

The binding properties of three p-tert-butyldihomooxacalix[4]arene tetraketone derivatives (tert-butyl 2b, adamantyl 2c and phenyl 2d) in the cone conformation and one derivative (methyl 2a) in a partial cone conformation, towards alkali and alkaline earth metal cations have been established by extraction studies of metal picrates from water into dichloromethane, stability constant measurements in methanol and acetonitrile, and by 1H NMR spectrometry. Transport experiments of metal picrates through a dichloromethane membrane were also performed. The results are compared to those obtained with closely-related calix[n]arene derivatives (n = 4 and 5) and discussed in terms of the substituents, size and conformational effects. Methylketone 2a is a poor binder for all the cations studied, due to its partial cone conformation. Ketones 2b, 2c and 2d show high extraction and complexation levels for the alkali cations, with similar profiles and preference for K+ and Na+ (plateau selectivity). Towards alkaline earth cations, these ketones show a strong peak selectivity for Ba2+ in extraction, but a plateau selectivity for Ca2+, Sr2+ and Ba2+ in complexation. The nature of the substituent attached to the ketone function has some influence on their binding properties, with phenylketone 2d being a slightly weaker binder than ketones 2b and 2c. 1H NMR titrations confirm the formation of 1:1 complexes between the ketones and the cations studied, also indicating that they should be located inside the cavity defined by the phenoxy and carbonyl oxygen atoms. Ketones 2b, 2c and 2d show transport rates that do not follow, in general, the same trends observed in extraction and complexation.

Complexation and Transport of Alkali and Alkaline Earth Metal Cations by p-tert-Butyldihomooxacalix[4]arene Tetraketone Derivatives

The binding properties of three p-tert-butyldihomooxacalix[4]arene tetraketone derivatives (tert-butyl 2b, adamantyl 2c and phenyl 2d) in the cone conformation and one derivative (methyl 2a) in a partial cone conformation, towards alkali and alkaline earth metal cations have been established by extraction studies of metal picrates from water into dichloromethane, stability constant measurements in methanol and acetonitrile, and by 1H NMR spectrometry. Transport experiments of metal picrates through a dichloromethane membrane were also performed. The results are compared to those obtained with closely-related calix[n]arene derivatives (n = 4 and 5) and discussed in terms of the substituents, size and conformational effects. Methylketone 2a is a poor binder for all the cations studied, due to its partial cone conformation. Ketones 2b, 2c and 2d show high extraction and complexation levels for the alkali cations, with similar profiles and preference for K+ and Na+ (plateau selectivity). Towards alkaline earth cations, these ketones show a strong peak selectivity for Ba2+ in extraction, but a plateau selectivity for Ca2+, Sr2+ and Ba2+ in complexation. The nature of the substituent attached to the ketone function has some influence on their binding properties, with phenylketone 2d being a slightly weaker binder than ketones 2b and 2c. 1H NMR titrations confirm the formation of 1:1 complexes between the ketones and the cations studied, also indicating that they should be located inside the cavity defined by the phenoxy and carbonyl oxygen atoms. Ketones 2b, 2c and 2d show transport rates that do not follow, in general, the same trends observed in extraction and complexation.

Synthesis, Conformational Analysis and Extraction Studies of p-isopropylcalix[n]arene Derivatives (n = 4, 6, 8). A New Family of Molecular Receptors

Ethers, esters and ketones, derivatives of p-isopropylcalix[n]arenes (n = 4,6,8), have been prepared; 33 new molecular receptors have been isolated and fully characterized. 1H NMR and 13C NMR measurements reveal that tetraester and tetraketone derivatives are in cone conformation at room temperature when hexa and octa derivatives look like flexible flattened cones. Extraction studies with metal picrates from aqueous solution into dichloromethane were used to assess the ionophoric activity of the p- isopropylcalix[n]arene derivatives. The better E% are obtained with tetrameric derivatives in cone conformation, fully functionalized on the phenolic oxygens by ester or ketonic groups. The tetraamide derivative is the most efficient binder; the E% values are around 100 for Li, Na, K, Rb, Cs, Ca and Ba.