1761-61-1Relevant articles and documents
Vanadium(V) complexes of some bidentate hydrazone ligands and their bromoperoxidase activity
Adak, Piyali,Ghosh, Bipinbihari,Pakhira, Bholanath,Sekiya, Ryo,Kuroda, Reiko,Chattopadhyay, Shyamal Kumar
, p. 135 - 143 (2017)
Dinuclear methoxy bridged complexes of vanadium, [VO(μ-OMe)(OMe)(L)]2(1–3) have been synthesized from the reaction of VOSO4·H2O with triethylamine and the respective hydrazone ligand. The compounds have been characterized by spectroscopic methods and determination of single crystal X-ray structure of one of them (1). DFT and TD-DFT calculations were used to understand the electronic structures of the complexes and their electronic spectra respectively. Though the dimeric complexes are stable in the solid state, the ESI-MS spectra as well as1H NMR spectra of the complexes suggest that in solution the monomeric forms of the complexes are the major species. The V(V) complexes in DMF were used to catalyze the oxidative bromination of salicylaldehyde, in aqueous H2O2/KBr in the presence of HClO4at room temperature. The complexes show exceptionally high bromoperoxidase activity with salicylaldehyde as a model substrate to produce 5-bromo salicylaldehyde in good yield and high TOF and TON. Therefore, these complexes behave as functional models of vanadate dependent bromoperoxidase enzyme.
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Barker et al.
, p. 1327 (1966)
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Efficient one-pot synthesis of ethyl [2-(2H-Chromene-3yl)-4-oxo-L,3- thiazolidin-3-yl]acetates
Reddy, S. Satyanarayana,Krupadanam, G. L. David
, p. 1305 - 1311 (2010)
Ethyl [2-(2H-chromene-3yl)-4-oxo-1,3-thiazolidin-3yl]acetates (6a-e) were synthesized in a single pot by the reaction of 2H-3-chromenecarbaldehydes (3a-e), glycine ethyl ester hydrochloride (4), and mercaptoacetic acid (5) in diisopropylethylamine/benzene under refluxing conditions in a Dean-Stark trap.
Copper(II) N, N, O-Chelating Complexes as Potential Anticancer Agents
Pe?a, Quim,Sciortino, Giuseppe,Maréchal, Jean-Didier,Bertaina, Sylvain,Simaan, A. Jalila,Lorenzo, Julia,Capdevila, Mercè,Bayón, Pau,Iranzo, Olga,Palacios, òscar
, p. 2939 - 2952 (2021)
Three novel dinuclear Cu(II) complexes based on a N,N,O-chelating salphen-like ligand scaffold and bearing varying aromatic substituents (-H, -Cl, and -Br) have been synthesized and characterized. The experimental and computational data obtained suggest that all three complexes exist in the dimeric form in the solid state and adopt the same conformation. The mass spectrometry and electron paramagnetic resonance results indicate that the dimeric structure coexists with the monomeric form in solution upon solvent (dimethyl sulfoxide and water) coordination. The three synthesized Cu(II) complexes exhibit high potentiality as ROS generators, with the Cu(II)/Cu(I) redox potential inside the biological redox window, and thus being able to biologically undergo Cu(II)/Cu(I) redox cycling. The formation of ROS is one of the most promising reported cell death mechanisms for metal complexes to offer an inherent selectivity to cancer cells. In vitro cytotoxic studies in two different cancer cell lines (HeLa and MCF7) and in a normal fibroblast cell line show promising selective cytotoxicity for cancer cells (IC50 about 25 μM in HeLa cells, which is in the range of cisplatin and improved with respect to carboplatin), hence placing this N,N,O-chelating salphen-like metallic core as a promising scaffold to be explored in the design of future tailor-made Cu(II) cytotoxic compounds.
Syntheses and characterization of monobasic tridentate Cu(II) Schiff-base complexes for efficient oxidation of 3,5-di-: tert -butylcatechol and oxidative bromination of organic substrates
Kumari, Sweta,Mahato, Arun Kumar,Maurya, Abhishek,Singh, Vijay Kumar,Kesharwani, Neha,Kachhap, Payal,Koshevoy, Igor O.,Haldar, Chanchal
, p. 13625 - 13646 (2017)
Two monomeric copper complexes [CuII(sal-ppzH)Cl2] (1) and [CuII(hyap-ppzH)Cl2] (2) were synthesized by reacting CuCl2·2H2O with the monobasic tridentate Schiff-base ligands [Hsal-ppz] (I) and [Hyap-ppz] (II) (derived by reacting 1-(2-aminoethyl) piperazine with salicylaldehyde and 2-hydroxyacetophenone) respectively. Elemental analysis, IR, UV-Vis, 1H NMR and 13C NMR data confirm the structures of the ligands and those of the complexes. Both complexes are monomeric in nature in the solid state and in solution as well. Single crystal XRD data suggest a distorted square pyramidal geometry for 1 crystallized in the P1 space group. DFT studies established a similar molecular structure for 2. The synthesized metal complexes [CuII(sal-ppzH)Cl2] (1) and [CuII(hyap-ppzH)Cl2] (2) successfully catalyzed the oxidation of 3,5-di-tert-butylcatechol (3,5-DTBC) in methanol in the presence of H2O2 with high Kcat values of 1.182 × 104 mmol h-1 and 2.880 × 104 mmol h-1, respectively. [CuII(sal-ppzH)Cl2] (1) and [CuII(hyap-ppzH)Cl2] (2) were also anchored into the polymeric matrix of chloromethylated polystyrene and were analyzed by TGA, atomic absorption spectroscopy (AAS), EPR, scanning electron microscopy (SEM) as well as energy dispersive X-ray (EDX) analysis. The polymer grafted metal complexes were used as catalyst precursors in the oxidative bromination of salicylaldehyde in the presence of H2O2, KBr and HClO4. Under optimized reaction conditions, both catalysts show nearly quantitative oxidative bromination of salicylaldehyde, with the order of % products formed being 5-bromosalicylaldehyde > 3,5-dibromosalicylaldehyde > 3-bromosalicylaldehyde. Plausible reactive species involved in the catalytic cycle are identified by UV-Vis spectroscopy, pH metric titration, ESI-MS, EPR and DFT studies.
Synthesis and characterization of Azo schiff bases and their β-lactam derivatives
Shinde, Anil H.,Patil
, p. 1520 - 1524 (2020)
Azo salicylaldehyde (I5) was synthesized by reaction of 5-bromo-salicylaldehyde with diazonium salt of 4-nitroaniline by diazotization method. Thus, synthesized azoaldehyde was treated with variable 2-aminobenzothiazoles (I6a-f) to synthesize the Schiff bases (I7a-f). The β-lactam derivatives (I8a-f) were also synthesized. All the newly synthesized compounds were characterized by TLC, UV-visible and FT-IR techniques.
Design and synthesis of novel Vitamin D-coumarin hybrids using microwave irradiation
Zhang, Hengrui,Fang, Zhijie
, p. 684 - 687 (2017)
A series of novel vitamin D-coumarin hybrids were synthesised by esterification of the corresponding coumarin-3-carboxylic acids and vitamin D or vitamin D CD-ring alcohol in CH2Cl2 under microwave irradiation. They were obtained in higher yields (from 64-81% up to 79-87%) and shorter reaction time (from 3 h down to 15 min), compared with earlier conventional methodologies. The structures of all the target compounds were confirmed by 1H NMR, 13C NMR and HRMS. This provides an attractive and alternative method for the preparation of high-value vitamin D-coumarin hybrids.
Ni-NiO heterojunctions: a versatile nanocatalyst for regioselective halogenation and oxidative esterification of aromatics
Bhardwaj, Nivedita,Goel, Bharat,Indra, Arindam,Jain, Shreyans K.,Singh, Ajit Kumar,Tripathi, Nancy
, p. 14177 - 14183 (2021/08/16)
Herein, we report a facile method for the synthesis of Ni-NiO heterojunction nanoparticles, which we utilized for the nuclear halogenation reaction of phenol and substituted phenols usingN-bromosuccinimide (NBS). A remarkablepara-selectivity was achieved for the halogenated products under semi-aqueous conditions. Interestingly, blocking of thepara-position of phenol offeredortho-selective halogenation. In addition, the Ni-NiO nanoparticles catalyzed the oxidative esterification of carbonyl compounds with alcohol, diol or dithiol in the presence of a catalytic amount of NBS. It was observed that the aromatic carbonyls substituted with an electron-donating group favoured nuclear halogenation, whereas an electron-withdrawing group substitution in carbonyl compounds facilitated the oxidation reaction. In addition, the catalyst was magnetically separated and recycled 10 times. The tuned electronic structure at the Ni-NiO heterojunction controlled selectivity and activity as no suchpara-selectivity was observed with commercially available NiO or Ni nanoparticles.