Showing papers on "Hydrazone published in 2020"
TL;DR: A review of the synthesis and biological activities of Schiff base, hydrazone and oxime derivatives of curcumin over the last decade is presented in this article, where the synthesis of different derivatives is an effective way to improve the medicinal and biological properties of Curcumin.
Abstract: Curcumin (1,7-bis[4-hydroxy-3-methoxyphenyl]-1,6-heptadiene-3,5-dione) is the main pigment present in the turmeric rhizome and shows various biological properties. The synthesis of different derivatives is an effective way to improve the medicinal and biological properties of curcumin. Many researchers have chosen the carbonyl group of curcumin for modification and preparation of new analogues. This review critically surveys a general overview of the literature and summarizes the synthesis and biological activities of Schiff base, hydrazone and oxime derivatives of curcumin over the last decade. These compounds and also their metal complexes possess higher potency in biological activity.
66 citations
TL;DR: In this paper, the synthesis and characterization of six Cu(II) and Zn(II)-complexes with 2-cetylpyridinenicotinichydrazone (HL) was reported.
47 citations
TL;DR: In this paper, the corrosion inhibition properties of a synthesized hydrazone derivative namely, 1-(4-isopropyl phenyl) -2- (2,4-dinitrophenyl) (HYD (iso)) on API 5L-X60 carbon steel (CS) in 1.0 m HCl solution were evaluated by chemical, electrochemical, X-ray photoelectron spectroscopy (XPS) and theoretical studies.
45 citations
TL;DR: Three asymmetric tridentate acyl hydrazone Schiff base ligands namely L1, L2 and L3 were prepared via condensation of 4-methoxybenzohydrazide with picolinaldehyde and showed the highest IC50 values for anti-cancer activity towards all three cell lines among the three complexes and complex 3 showed the least activity as observed in the phosphatase activity study.
Abstract: Three asymmetric tridentate acyl hydrazone Schiff base ligands namely L1, L2 and L3 were prepared via condensation of 4-methoxybenzohydrazide with picolinaldehyde, 1-(pyridin-2-yl)ethanone and phenyl(pyridin-2-yl)methanone respectively. Three bio-relevant mononuclear zinc(II) complexes [Zn(L1)Cl2]·2H2O (1), [Zn(L2)Cl2] (2) and [Zn(L3)Cl2] (3) were synthesized by treatment of zinc(II) chloride with the corresponding Schiff base ligands and characterised by the usual physicochemical techniques. The solid state structures of complexes 1 and 3 were evaluated by single crystal X-ray analysis. All complexes were able to hydrolyse the P–O bond of the phosphate monoester in 90% (v/v) DMSO–water medium using 4-nitrophenylphosphate (4-NPP) as the model substrate and the trend in their activity is 1 ≈ 2 > 3. On considering the highly efficient hydrolysis properties, complexes 1–3 were tested as potential therapeutic agents for cancer using HCT116 (human colorectal carcinoma), HepG2 (human hepatocellular carcinoma) and A549 (human non-small lung carcinoma) cells. Complex 2 showed the highest IC50 values for anti-cancer activity towards all three cell lines among the three complexes and complex 3 showed the least activity as observed in the phosphatase activity study. The internucleosomal degradation of DNA during apoptosis can be detected by cell death detection ELISA. DNA fragmentation that leads to cell death was examined and when induced by complex 2 in HepG2 cells a significant level of DNA fragmentation was observed at regular intervals of time.
40 citations
TL;DR: Two receptors for fluoride ions based on acyl hydrazone are synthesized from the corresponding ketones and benzoic acid hydrazide and characterized spectroscopically by UV-visible, IR and 1HNMR techniques, indicating the participation of -NH proton of the receptors in the sensing action through the hydrogen bonding.
35 citations
34 citations
TL;DR: Design and synthesis of different series of novel small molecules featuring 3-methylthiazolo[3,2-a]benzimidazole moiety connected to the zinc anchoring benzenesulfonamide moiety via ureido, enaminone, hydrazone, or hydrazide linkers are described.
34 citations
TL;DR: A quinoline-based hydrazone, namely, bis((quinolin-8-yl)methylene)carbonohydrazide (1), has been designed and synthesized, which could be used as a dual probe for selective recognition of Co2+ and Zn2+ by monitoring changes in absorption and fluorescence spectral pattern, respectively.
31 citations
TL;DR: In this article, a new Cu(II), Co(III) and Ni(II) metal complexes of N'-(3-ethoxy-2-hydroxybenzylidene)acetohydrazide (ehbahH2) ligand derived from 3-ethoxysalicylaldehyde and acethydrazide were obtained.
31 citations
29 citations
TL;DR: It was showed that antitubercular activity of novel hydrazone derivatives of eugenol is strongly connected with the position of the substituent on aromatic aldehyde or ketones.
TL;DR: All BOPAHY dyes show excellent photophysical properties with quantum yields up to 0.92, and Steady-state spectroscopy and quantum chemical calculations provide a first insight into these promising properties.
TL;DR: Twenty-eight 5-pyrrolidine-2-ones decorated by hydrazine or acyl hydrazones groups have been designed, synthesized and evaluated as antifungal agents on a panel of twelve fungal strains and three non albicans candida yeasts species which have demonstrated reduced susceptibility to commonly used antIFungal drugs.
TL;DR: In this article, two optical probes 1 and 2 were presented for detecting hydrazine incorporating malononitrile and 2-benzothiazoleacetonitrile, respectively.
TL;DR: Direct synthesis of N2-substituted triazole and triazine derivatives has been a challenge in N-heterocyclic chemistry and mechanistic studies have revealed that the reaction proceeds via alkenyl azo/imino hydrazone intermediates.
TL;DR: In this article, a trivalent mononuclear ternary complexes of the type, [ML1L2] [M = Cr(III), Fe(III) and La(III], HL1 = 2-((2,4-dinitrophenyl)hydrazone)methyl)phenol, HL2= 2-aminophenol] was investigated by various physio-chemical studies.
TL;DR: A ruthenium-catalysed redox-neutral α-alkylation of unsaturated alcohols through the synergistic relay of olefin isomerization (chain-walking) and 'umpolung' hydrazone addition, which impeccably takes advantage of the interaction of the two comparatively inefficient clause reactions to enable them to occur in an efficient way.
Abstract: Herein, we report a ruthenium-catalyzed redox-neutral α-alkylation of unsaturated alcohols based on a synergistic relay process involving olefin isomerization (chain walking) and umpolung hydrazone addition, which takes advantage of the interaction between the two rather inefficient individual reaction steps to enable an efficient overall process. This transformation shows the compatibility of hydrazone-type "carbanions" and active protons in a one-pot reaction, and at the same time achieves the first Grignard-type nucleophilic addition using olefinic alcohols as latent carbonyl groups, providing a higher yield of the corresponding secondary alcohol than the classical hydrazone addition to aldehydes does. A broad scope of unsaturated alcohols and hydrazones, including some complex structures, can be successfully employed in this reaction, which shows the versatility of this approach and its suitability as an alternative, efficient means for the generation of secondary and tertiary alcohols.
TL;DR: In this article, a hydrazone ligand was synthesized from furan-2-carbohydrazide and indole-3-carboxaldehyde, which was shown to have superior activity against A549 and HeLa cancer cells with IC50 values of 23.4 and 12.9 µm, respectively.
TL;DR: Although the antimicrobial effects of quinoline derivatives, in general, are weaker than standard drugs; 3q5 and 3q6 against MRSA showed promising activity with MIC:16 µg/ml compared to reference drugs.
TL;DR: It is demonstrated that the hydrazone linkages and the heptazine units synergistically enhance the photocatalytic activity of PCNs in visible-light-driven aerobic oxidation of benzyl alcohol to benzaldehyde.
Abstract: Heptazine-based conjugated polymeric carbon nitrides (PCNs) are promising metal-free photocatalysts, yet their synthesis is challenging due to the electron-deficiency and insolubility of heptazine units. Indeed, heptazine-containing polymers have only been prepared through nucleophilic substitution with amines by using toxic cyameluric chloride as the starting material. Herein, we report the novel and environmentally friendly method for preparing heptazine-based mesoporous PCNs with hydrazone links formed through a simple Schiff base condensation of melem-NH2 and aldehydes. Unlike cyameluric chloride, melem-NH2 is non-toxic, stable, and can be readily obtained from melem and hydrazine in solution. We demonstrate that the hydrazone linkages and the heptazine units synergistically enhance the photocatalytic activity of PCNs in visible-light-driven aerobic oxidation of benzyl alcohol to benzaldehyde. In particular, the polymer constructed from melem-NH2 and p-phthalaldehyde shows 17 times more activity than graphitic carbon nitride (g-C3 N4 ).
TL;DR: In this article, a copper hydrazone complex with (Z)-2-(phenyl(2-(pyridin-2-yl)hydrazono)methyl)pyridine (L) was synthesized and characterized using various physicochemical methods.
TL;DR: In this paper, an aromatic α, β-unsaturated Ketone (2E,5E)-2,5 bis(4-isopropyl benzylidene) cyclopentanone (A) have been achieved by a Claisen-Schmidt reaction.
TL;DR: The present C-O and N-S bond-forming difunctionalization strategy affords diversely functionalized N-acylsulfonamides in good yield and suggests a radical mechanistic pathway of the present reaction.
15 Dec 2020
TL;DR: In this paper, a thermochromic urea (U) organogel with tricyanofuran hydrazone (TCFH) chromophore was developed.
Abstract: Thermochromic urea (U) organogel immobilized with a thermochromic tricyanofuran hydrazone (TCFH) chromophore was developed. Thermochromic TCFH chromophore bearing two nitro functional groups on a hydrazone recognition unit was synthesized via an azo-coupling reaction of tricyanofuran (TCF) heterocyclic moiety containing an active methyl group with the diazonium chloride salt of 2,4-dinitroaniline comprising two strongly electron-withdrawing nitro groups. The molecular structure of both intermediates and TCFH dye were characterized by several analytical methods, including 1H NMR, 13C NMR, IR, mass spectroscopy (MS), and elemental analysis. The thermochromic responsiveness could be attributed to the charge delocalization of TCFH as well as to the presence of an intramolecular charge transfer. The generated organogel displayed a thermoreversible sol–gel transition associated with color change. The origin of the monitored thermochromism is a conformational change of the tricyanofuran hydrazone backbone due to the temperature-driven deprotonation–protonation reversible process. The prepared urea–tricyanofuran hydrazone (UTCFH) thermometer acted as a diagnostic tool providing an instant color change between yellow, orange, red and purple upon changing the temperature of the UTCFH organogel in dimethyl sulfoxide (DMSO). This color change was proportionally correlated with increasing the temperature from 44 to 63 °C. The UTCFH organogel composed of urea and push-π-pull hydrazone type tricyanofuran chromophore immobilized physically in the urea organogel was found to function as a temperature-driven chromic thermometer. This chromogenic UTCFH organogel in DMSO displayed a phase transition at 41–48 °C. The morphological properties of the gel internal fibrous nanostructure (80–120 nm) were monitored by scanning electron microscopy (SEM). The colorimetric measurements were monitored by UV–Vis absorption spectroscopy. The chromogenic thermometer demonstrated a good reversibility without fatigue. The mechanism accounting for thermochromism of UTCFH organogel is proposed.
TL;DR: In this paper, a novel hydrazone compound, namely 1-(5-bromo-2,3-dimethoxybenzylidene)-2-(pyridine-2-yl) hydrazine (5Br2DM2PH), was synthesized by condensation reaction in acidic conditions.
TL;DR: A denitrogenative palladium-catalyzed cascade for the modular and regioselective synthesis of polysubstituted fluorenes with scalable and adaptable to a three-component reaction with in situ generation of the hydrazone group is reported.
Abstract: We herein report a denitrogenative palladium-catalyzed cascade for the modular and regioselective synthesis of polysubstituted fluorenes. Hydrazone facilitates the Pd(II) to Pd(IV) oxidative addition in a Catellani pathway and is also the methylene synthon in the proposed reaction. Aryl iodides and 2-bromoarylaldehyde hydrazones undergo a norbornene-controlled tandem reaction sequence to give a broad scope of fluorenes in the presence of a palladium catalyst. The method described is scalable and adaptable to a three-component reaction with in situ generation of the hydrazone group. Preliminary mechanistic investigations have been conducted.
TL;DR: In this paper, a Schiff base derivative, (E)-3-(1-(2-(9H-fluoren-9-ylidene)hydrazineyl)ethylidene)-6-methyl-2H-pyran-2,4(3H)-dione, was synthesized via subsequent condensation/tautomerization processes in a high yield.
TL;DR: Pyridyl benzothiazole hydrazone derivatives containing ruthenium, rhodium and iridium complexes have been synthesized, characterized and evaluated for antimicrobial activity.
TL;DR: The synthesized new structure of hydrazone complexed with copper (II) shows antimicrobial activity, and magnetic susceptibility results indicate weak antiferromagnetic coupling between the copper atoms.
TL;DR: In this article, microwave assisted approach was utilized as green approach to access a series of 2-propylquinoline-4-carbohydrazide hydrazone derivatives of aromatic and hetero-aromatic aldehydes in highly encouraging yields.