15062-34-7Relevant academic research and scientific papers
Selective Bromination of β-Positions of Porphyrin by Self-Catalytic Behaviour of VOTPP: Facile Synthesis, Electrochemical Redox Properties and Catalytic Application
Maurya, Mannar R.,Prakash, Ved,Avecilla, Fernando,Sankar, Muniappan
, p. 1685 - 1694 (2021/05/03)
Oxidovanadium(IV) complex of β-octabromo-meso-tetraphenylporphyrin, {[VIVO(TPPBr8)], 2} was synthesized by self-catalytic oxidative bromination of meso-tetraphenylporphyrinatooxidovanadium(IV) {[VIVO(TPP), 1} in excellent yield under mild conditions at 25 °C and its structure was confirmed by single crystal X-ray study. UV-Vis and 1H NMR spectra further confirmed that the meso-phenyl rings are not brominated and thus emphasizes on the selectivity as well as synthetic importance of this catalytic method. In the presence of substrates e. g. phenol derivatives, 1 biomimics the vanadium bromoperoxidase (VBPO) enzyme and catalyses the oxidative bromination of substrates in water at 25 °C. Remarkably, 2 also catalyses the oxidative bromination of phenol derivatives under similar reaction conditions with very high turnover frequency (TOF) values (ca. 29 s?1) along with its recyclability. It was found that 2 showed superior catalytic performance as compared to 1 because of its electron deficient nature due to electron withdrawing bromo substituents and robust saddle shaped nonplanar structure (further supported by DFT studies).
Biomimetic Oxidative Bromination by cis-Dioxidotungsten(VI) Complexes of Salan Type N,N’-Capped Linear Tetradentate Amino Bisphenol
Maurya, Mannar R.,Maurya, Shailendra K.,Kumar, Naveen,Gupta, Puneet
, p. 2724 - 2738 (2021/06/18)
Reaction of [WVIO2(acac)2] (Hacac=acetylacetone) with salan-type dibasic tetradentate ONNO donor Mannich bases derived from ethylenediamine, formaldehyde and 2,4-di-tert-butylphenol (H2L1), 2-tert-butyl-4-methylphenol (H2L2), 2,4-dimethylphenol (H2L3) and 2,4-dichlorophenol (H2L4) in a 1 : 1 ([WVIO2(acac)2] : H2L) molar ratio in refluxing MeOH gave the corresponding cis-dioxidotungsten(VI) complexes [WVIO2L1] (1), [WVIO2L2] (2), [WVIO2L3] (3) and [WVIO2L4] (4), respectively. Characterization by elemental analysis, various spectroscopic (FT-IR, UV-vis, 1H and 13C NMR) studies, DFT calculations and single-crystal X-ray analysis of 2 and 3 suggest six-coordinated octahedral α-cis (symmetric) isomeric form of the complexes where ligands coordinate through the two phenolate oxygen and two amine nitrogen atoms (in a cis-α type symmetric binding mode) with one of the N atoms of the ligand and one of the terminal O atoms of the cis-WO2 group in the axial position. These complexes are potential catalyst precursors for the oxidative bromination of thymol and styrene. Thymol upon bromination gave three products, namely, 2-bromothymol, 4-bromothymol, and 2,4-dibromothymol; later one being the major product. Oxidative bromination of styrene resulted in 2-bromo-1-phenylethanol and 1-phenylethane-1,2-diol; the later one is the result of nucleophilic attack of water on the α as well as β carbons both of the initially formed 1,2-dibromo-1-phenylethane.
Lignosulfonate microcapsules for delivery and controlled release of thymol and derivatives
Piombino, Claudio,Lange, Heiko,Sabuzi, Federica,Galloni, Pierluca,Conte, Valeria,Crestini, Claudia
, (2020/02/25)
Thymol and the corresponding brominated derivatives constitute important biological active molecules as antibacterial, antioxidant, antifungal, and antiparasitic agents. However, their application is often limited, because their pronounced fragrance, their poor solubility in water, and their high volatility. The encapsulation of different thymol derivatives into biocompatible lignin-microcapsules is presented as a synergy-delivering remedy. The adoption of lignosulfonate as an encapsulating material possessing relevant antioxidant activity, as well as general biocompatibility allows for the development of new materials that are suitable for the application in various fields, especially cosmesis. To this purpose, lignin microcapsules containing thymol, 4-bromothymol, 2,4-dibromothymol, and the corresponding O-methylated derivatives have been efficiently prepared through a sustainable ultrasonication procedure. Actives could be efficiently encapsulated with efficiencies of up to 50%. To evaluate the applicability of such systems for topical purposes, controlled release experiments have been performed in acetate buffer at pH 5.4, to simulate skin pH: all of the capsules show a slow release of actives, which is strongly determined by their inherent lipophilicity.
A shan tiefen derivative and its synthetic method and application in pesticide
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Paragraph 0050-0053, (2019/07/08)
The invention relates to a shan tiefen derivative and its synthetic method and in pesticide application, especially in the application of the pesticide in the fungicide, which belongs to the technical field of agricultural chemicals. The invention solves the technical problem is to provide a new shan tiefen derivative and its synthetic method and in pesticide application, the structure of this compound is shown as formula I. This compound the structure is simple, novel, easy to synthesize, at the same time having fungicidal activity, the tomato alteso, zones all of tomato, cucumber wilt disease, magnaporthe grisea, galenical such important plant pathogenic fungi, have better bacteriostatic or bactericidal effect.
Synthesis and antifungal activity of carvacrol and thymol esters with heteroaromatic carboxylic acids
Fan, Liming,Jiang, Shanshan,Su, Fawu,Wang, Kaibo,Yang, Yunhai,Ye, Min
, p. 1924 - 1930 (2018/06/11)
Aiming to obtain the more effective pathogen inhibitive ingredients and explore the influence of introducing different heterocyclic units to carvacrol and thymol esters, twenty ester derivatives with different heterocyclic units were synthesized. And the
Synthesis, characterization and catalytic activity of dioxidouranium(VI) complexes of ONNO tetradentate Mannich bases
Avecilla, Fernando,Maurya, Mannar R.,Maurya, Shailendra K.,Mengesha, Bekele
supporting information, p. 118 - 126 (2019/06/28)
The reaction of dibasic tetradentate ONNO donor Mannich bases, derived from ethylenediamine and 2,4–di–tert–butylphenol (H2L1) (I), 2,4–di–methylphenol (H2L2) (II), 2–tert–butyl–4–methylphenol (H2L3) (III) and 2,4–di–chlorophenol (H2L4) (IV), with UVIO2(MeCOO)2·2H2O in a 1:1 M ratio in refluxing MeOH gave the corresponding mononuclear trans-dioxidouranium(VI) complexes of the type trans-[UVIO2L(MeOH)] (H2L = H2L1 to H2L4) (1–4). The synthesized complexes are stable in air, reddish-brown in color and soluble in most solvents. These complexes are characterized by elemental analysis, various spectroscopic (FT-IR, UV/Vis, 1H and 13C NMR) techniques and single-crystal X-ray analysis of 3 and 4. The complexes adopt distorted pentagonal bipyramidal geometry around the metal centre. The ligand acts as tetradentate, coordinating through two phenolato oxygen and two imino nitrogen atoms; two oxido groups are trans to each other. These complexes are used as catalysts to study the oxidative bromination of thymol and styrene. The catalytic oxidative bromination of thymol resulted in the formation of three products namely, 2-bromothymol, 4-bromothymol and 2,4-dibromothymol while oxidative bromination of styrene gave two products, 2-bromo-1-phenylethane-1-ol and 1-phenylethane-1,2-diol. In order to find out the optimized reaction conditions for the fixed concentration (10 mmol) of substrate, effects of different amounts of catalyst, KBr, HClO4, and oxidant (H2O2) have been investigated. Under the optimized reaction conditions, all the complexes have shown good catalytic potentials for the oxidative bromination of substrates, establishing the functional similarity to vanadium dependent haloperoxidases. Changes in the UV–visible absorption spectra of dioxidouranium(VI) complexes upon addition of H2O2 suggest the formation of the corresponding oxidoperoxidouranium(VI) complexes.
4,6-Diacetyl Resorcinol Based Vanadium(V) Complexes: Reactivity and Catalytic Applications
Maurya, Mannar R.,Jangra, Nancy,Avecilla, Fernando,Correia, Isabel
, p. 314 - 329 (2019/01/24)
Four ONO donor ligands are isolated from the condensation of 4,6-diacetyl resorcinol with isonicotinoyl hydrazide (H2dar-inh, I), nicotinoyl hydrazide (H2dar-nah, II), benzoyl hydrazide (H2dar-bhz, III), and 2-furoyl hydrazide (H2dar-fah, IV) on refluxing in MeOH. The reaction of in situ generated aqueous K[H2VVO4] with ligands I–IV at neutral pH gives complexes [K(H2O)2][VO2(dar-inh)] (1), [K(H2O)2][VO2(dar-nah)] (2), [K(H2O)2][VO2(dar-bhz)] (3), and [K(H2O)2][VO2(dar-fah)] (4), respectively. The reaction of [VIVO(acac)2] (acac = acetylacetonato) with these ligands (I–IV) under aerobic conditions in methanol yields oxidomethoxidovanadium(V) complexes [VO(OMe)(MeOH)(dar-inh)] (5), [VO(OMe)(MeOH)(dar-nah)] (6), [VO(OMe)(MeOH)(dar-bhz)] (7), and [VO(OMe)(MeOH)(dar-fah)] (8). All the isolated complexes are characterized by elemental, thermal, electrochemical, and spectroscopic techniques [FTIR, UV/Vis, NMR (1H, 13C and 51V NMR)], and single-crystal X-ray diffraction analysis (for 1, 6, 7, and 8). X-ray analysis confirms the coordination of the ligands through Ophenolate, Nazomethine, and Oenolate to the metal center. In the molecular structure of [K(H2O)(EtOH)][VVO2(dar-inh)] (abbreviated as 1a where one molecule of water is replaced by EtOH), water molecules act as bridges between two K+ ions and the complex shows a dimeric structure due to the presence of electrostatic interactions between V=O oxygen atoms with K+ ions. These complexes are active catalysts for the oxidative bromination of thymol in the presence of KBr, HClO4, and H2O2 and give 2-bromothymol, 4-bromothymol, and 2,4-dibromothymol as major products. Complexes 1–4 were also tested as catalysts for the epoxidation of various alkenes (namely styrene, cyclohexene, cis-cyclooctene, 1-hexene, 1-octene, cyclohexenone, and trans-stilbene) with H2O2 in the presence of NaHCO3 as promoter, giving the corresponding epoxides selectively.
Robust and electron deficient oxidovanadium(iv) porphyrin catalysts for selective epoxidation and oxidative bromination reactions in aqueous media
Dar, Tawseef Ahmad,Uprety, Bhawna,Sankar, Muniappan,Maurya, Mannar R.
, p. 1757 - 1768 (2019/04/08)
meso-Tetrakis(3,5-dimethoxyphenyl)porphyrinatooxidovanadium (1) and β-octabromo-meso-tetrakis(2,6-dibromo-3,5-dimethoxyphenyl)porphyrinatooxidovanadium (2) were synthesized in excellent yields. The synthesized oxidovanadium(iv) porphyrin complexes were characterized by various spectroscopic methods such as UV-Vis, FT-IR, EPR and MALDI-TOF mass spectrometry, as well as by single crystal X-ray crystallography. The acetonitrile coordinated porphyrin 1 is relatively planar whereas 2 is highly nonplanar as shown by their crystal structures and also by electrochemical studies. Selective epoxidation studies of alkenes were successfully carried out in CH3CN/H2O as the solvent mixture at ambient temperature resulting in very high TOF numbers (12227-14347 h-1 for 2) even with low catalyst loadings. Remarkably, 2 biomimics the vanadium bromoperoxidase (VBrPO) enzyme with extremely high TOF values (83333-87719 h-1) for the oxidative bromination of thymol and some other phenols. Both the catalysts were successfully recovered at the end of the reactions, indicating their viability and industrial applicability.
Dioxidomolybdenum(VI) and dioxidouranium(VI) complexes as functional mimic of haloperoxidases catalytic activity in presence of H2O2–KBr–HClO4
Maurya, Mannar R.,Mengesha, Bekele,Maurya, Shailendra K.,Sehrawat, Nidhi,Avecilla, Fernando
, p. 757 - 765 (2018/12/13)
The stable dibasic tetradentate ligand 1,4-bis-(2-hydroxy-3,5-dimethylbenzyl)piperazine (H2pip-2,4-dmp, I) prepared by reacting 2,4-dimethylphenol with piperazine in the presence of formaldehyde reacts with [MoVIO2(acac)s
In vitro cytotoxicity and catalytic evaluation of dioxidovanadium(v) complexes in an azohydrazone ligand environment
Mohanty, Monalisa,Maurya, Shailendra K.,Banerjee, Atanu,Patra, Sushree Aradhana,Maurya, Mannar R.,Crochet, Aurélien,Brzezinski, Krzysztof,Dinda, Rupam
, p. 17680 - 17695 (2019/11/26)
Three new anionic dioxidovanadium(v) complexes (HNEt3)[VO2(L)1-3] (1-3) of tridentate binegative aroylhydrazone ligands containing the azobenzene moiety were synthesized and structurally characterized. The aroylhydrazone ligands (H2L1-3) were derived from the condensation of 5-(arylazo) salicylaldehyde derivatives with the corresponding aroyl hydrazides. All the synthesized ligands and metal complexes were successfully characterized by several physicochemical techniques, namely, elemental analysis, electrospray ionization mass spectrometry, spectroscopic methods (IR, UV-vis and NMR), and cyclic voltammetry. Single-crystal X-ray diffraction crystallography of 1-3 revealed five-coordinate geometry, where the ligand coordinates to the metal centre in a binegative tridentate O, N, O coordinating anion and two oxido-O atoms, resulting in distortion towards the square pyramidal structure. The complexes were further evaluated for their in vitro cytotoxicity against HeLa and HT-29 cancer cell lines. All the complexes manifested a cytotoxic potential that was found to be comparable with that of clinically referred drugs, while complex 3 proved to be the most cytotoxic among the three complexes for both cell lines, which may be due to the synergistic effect of the naphthyl substituent in the azohydrazone ligand environment coordinated to the vanadium metal. The synthesized complexes 1-3 were probed as catalysts for the oxidative bromination of thymol and styrene as a functional mimic of vanadium haloperoxidases (VHPOs). All the reactions provided high percentages of conversion (>90%) with a high turnover frequency (TOF) in the presence of the catalysts 1-3. In particular, for the oxidative bromination of thymol, the percentage of conversion and TOF were in the ranges of 98-99% and 5380-7173 (h-1), respectively. Besides, 3 bearing the naphthyl substituent showed the highest TOF among all the complexes for the oxidative bromination of both thymol and styrene.
