- DNA-binding study of nickel(II) and zinc(II) complexes with two novel chromenone-based Schiff-base ligands
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Two new chromenone-based Schiff-base ligands, 3-{[(1,5-dihydro-3-methyl-5- thioxo-4H-1,2,4-triazol-4-yl)imino]methyl}-6-hydroxy-4H-1-benzopyran-4-one (L1) and 2,2′-bis[(6-hydroxy-4-oxo-4H-1-benzopyran-3-yl) methylene]carbonothioic dihydrazide (L2), and their NiII and ZnII complexes were prepared. All the complexes were characterized by elemental analysis, IR data, and molar conductivity. The binding of these four complexes to calf-thymus DNA was carefully investigated by UV/VIS spectroscopy, fluorescence spectroscopy, viscosity measurements, and CD spectra. The experimental results indicate that the four complexes bind to calf-thymus DNA in an intercalative mode, with the intrinsic binding constants (K) of 3.94·104 ([NiL1]), 5.15·10 3 ([ZnL1]), 4.12·104 ([NiL 2]), and 3.75·104 m-1 ([ZnL 2]). These data show that the complexes of L2 can interact more strongly with DNA than complexes of L1, and the NiII complexes have a higher binding constant than ZnII complexes.
- Qin, Dong-Dong,Yang, Zheng-Yin,Li, Tian-Rong,Qi, Gao-Fei
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- Photohydrodimerization of 6-methoxyflavone to 6,6″-dimethoxy-2, 2″-biflavanones
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6-Methoxyflavone (7) easily afforded two hydrodimers of rac-6,6″-dimethoxy-2,2″-biflavanone (8a) and meso-6,6″- dimethoxy-2,2″-biflavanone (8b) and one reductive product of 6-methoxyflavanone (9) by using photolysis with the electron-donating amines including triethylamine, 2-(N,N-dimethylamino)ethanol or N,N-dimethylaniline in solvents of acetonitrile, benzene or methylene dichloride. They were found to give higher yields of rac-6,6″-dimethoxy-2,2″-biflavanone (8a) and meso-6,6″-dimethoxy-2,2″-biflavanone (8b) (38.7% and 4.5%, 35.3% and 6.2%, respectively) in the reaction conditions of 1/10 molar ratio of 6-methoxyflavone (7) to triethylamine in a solvent of acetonitrile with irradiation of twenty-four hours by using 306 nm and 352 nm lamps.
- Chen, Arh-Hwang,Kuo, Wei-Bao,Chen, Chia-Wen
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- Nano-sized mesoporous phosphated tin oxide as an efficient solid acid catalyst
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Herein, we prepared a mesoporous tin oxide catalyst (mSnO2) activated with phosphate species by the adsorption of phosphate ions from a phosphoric acid solution onto tin oxyhydroxide (Sn(OH)4) surface. The phosphate content ranged from 3 to 45 wt%. The nonaqueous titration of n-butylamine in acetonitrile was used to determine the total surface acidity level. FTIR of chemically adsorbed pyridine was used to differentiate between the Lewis and Br?nsted acid sites. Thermal and X-ray diffraction analysis indicated that the addition of phosphate groups stabilized the mesostructure of mSnO2 and enabled it to keep its crystalline size at the nanoscale. FTIR analysis indicated the polymerization of the HPO42? groups into P2O74?, which in turn reacts with SnO2 to form a SnP2O7 layer, which stabilizes the mesoporous structure of SnO2. The acidity measurements showed that the phosphate species are distributed homogeneously over the mSnO2 surface until surface saturation coverage at 25 wt% PO43?, at which point the acid strength and surface acidity level are maximized. The catalytic activity was tested for the synthesis of hydroquinone diacetate, where it was found that the % yield of hydroquinone diacetate compound increased gradually with the increase in PO43? loading on mSnO2 until it reached a maximum value of 93.2% for the 25% PO43?/mSnO2 catalyst with 100% selectivity and excellent reusability for three consecutive runs with no loss in activity.
- Hassan, S. M. Hassan,Mannaa,Ibrahim, Amr Awad
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- Antioxidant activity of prenylated hydroquinone and benzoic acid derivatives from Piper crassinervium Kunth
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Growing evidence suggests that RNOS (reactive nitrogen and oxygen species) are involved in the damage of biomolecules, contributing to the aetiology of several human diseases. Thus, the demand for antioxidants has stimulated the search for new compounds with potential use in this field. The in vitro antioxidant potential of prenylated hydroquinones and prenylated 4-hydroxy-benzoic acids from fruits of P. crassinervium was evaluated in terms of their capacity to suppress both DPPH (2,2-diphenyl-1-picrylhydrazyl) radical and chemiluminescence produced from luminol, using 2,2′-azo-bis(2-amidinopropane) (ABAP) as a peroxyl radical source. The inhibition of lipid peroxidation was assessed using liposomes from phosphatidylcholine as a membrane model. The prenylated hydroquinones had higher antioxidant activity than the benzoic acids and, among the hydroquinones, the E isomer was more efficient than the Z isomer.
- Yamaguchi, Lydia F.,Lago, Joao Henrique G.,Tanizaki, Tatiane M.,Mascio, Paolo Di,Kato, Massuo J.
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- A new off-on fluorescent sensor for the detection of Al(III) based on a chromone-derived Schiff-base
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A new Al3+ sensor, 6-ethoxychromone-3-carbaldehyde-(3-hydroxy-2-naphthalene acyl) hydrazone (L), was designed and synthesized. The sensor L could exist steadily and detect Al3+ in the pH range from 5.0 to 8.0 in ethanol and water (3:1, v/v). This sensor showed good selectivity and high sensitivity towards Al3+ in the presence of most metal ions, and a remarkable enhancement in fluorescence emission intensity at 508 nm (λex = 420 nm) was observed with addition of 1equiv Al3+, which was attributed to the inhibition of photoinduced electron-transfer (PET) phenomenon and C[dbnd]N isomerization process. With the fluorescence titration experiments and the ESI-MS spectrum data, we reached the conclusion that the binding ratio between L and Al3+ was 2:1. Besides, the binding constant (Ka) between L and Al3+ was calculated to be 9.24 × 103 M?1 and the detection limit of L for Al3+ was as low as 1.82 × 10?7 M.
- Liu, Li-mei,Yang, Zheng-yin
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- A novel chromone derivative as dual probe for selective sensing of Al(III) by fluorescent and Cu(II) by colorimetric methods in aqueous solution
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Based on the chromone skeleton, a simple and novel probe that is 6-ethoxychromone-3-carbaldehyde-(furanyl) hydrazone (L) has been synthesized and completely characterized. It exhibited representative turn-on fluorescent properties and obviously colorimetric changes with high selectivity to Al3+ and Cu2+. For Al3+, L displayed a turn on green fluorescence in EtOH/H2O (3/2) aqueous media over other common cations. With Cu2+, L perceived Cu2+ through the naked-eye by the color changed-from colorless to yellow. Moreover, the coordination ratio between L-Al3+and L-Cu2+ was 1:1 which could be verified by the Job's plot, 1H NMR and high-resolution mass spectrum. Consequentially, L could be used as a solid probe for both Al3+ and Cu2+.
- Tian, Limei,Xue, Jia,Li, Si-liang,Yang, Zheng-yin
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- Na 2 CO 3-Catalyzed O-Acylation of Phenols for the Synthesis of Aryl Carboxylates with Use of Alkenyl Carboxylates
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Inorganic base-catalyzed O-acylation of phenol and its derivatives has been developed. The procedure provides an efficient catalysis system for the preparation of aryl carboxylates with alkenyl carboxylates as acyl reagents. The reaction proceeded smoothly by using ?-Na 2 CO 3 as the catalyst in MeCN to produce the corresponding aryl carboxylates in good to excellent yields.
- Zhou, Xiao-Yu,Chen, Xia
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- A chromone-derived Schiff-base as Al3+“turn-on” fluorescent probe based on photoinduced electron-transfer (PET) and C[dbnd]N isomerization
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In this study, a novel chromone-derived Schiff-base ligand which was called bis(6-hydroxychromone-3-methylidene)-o-phenylenediimine (1) was designed, synthesized, and evaluated as an Al3+“turn on” fluorescent probe. This probe 1 showed good selectivity and high sensitivity towards Al3+in the presence of most metal ions, and a remarkable enhancement by about 30.91-fold in fluorescence emission intensity at 459?nm was observed with addition of 1?equiv of Al3+, which was attributed to the inhibition of photoinduced electron-transfer (PET) phenomenon and C[dbnd]N isomerization process at the excited state. Moreover, the fluorescence response of 1 to Al3+was nearly completed within 10?min. Thus, this probe 1 could be utilized for sensing and monitoring Al3+in environmental and biological systems for real-time detection.
- Li, Chao-rui,Li, Si-liang,Yang, Zheng-yin
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- Microwave-assisted acetylation of phenols without catalyst under solvent free condition
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Etherification between phenols with acetic anhydride was tested under different conditions. Phenols were efficiently acylated with acetic anhydride to give phenol acetate derivatives in good high yields without catalyst and solventless conditions under microwave irradiation.
- Zhang, Yu-Quan,Li, Yan-Chun,Zhu, Ji-Hua,Li, Zhi-Feng,Guo, Guo-Zhe,Chen, Dong-Ping
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- A novel chromone and rhodamine derivative as fluorescent probe for the detection of Zn(II) and Al(III) based on two different mechanisms
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In this study, a novel fluorescent probe, 6?hydroxychromone?3?carbaldehyde?(rhodamine B carbonyl) hydrazine (L), for Zn2+ and Al3+ was designed and synthesized. Initially, this probe L exhibited inferior fluorescence emission peak centered at 488 nm in EtOH/HEPES solution (3/1, 10.0 μM HEPES, pH 7.4) when excited at 421 nm. After the addition of Zn2+, this probe L displayed excellent selectivity towards Zn2+ with obvious fluorescence color change from colorless to yellow, which might be attributed to the formation of a 1:1 ligand-metal complex resulting in the inhibition of photo-induced electron transfer phenomenon. Whereas, the prepared Zn2+ complex of L could be used as a ratiometric fluorescent probe to detect Al3+ on the basis of fluorescence resonance energy transfer mechanism. This ligand-metal complex of Zn2+ (LZn) showed high selectivity towards Al3+ with obvious enhancement in fluorescence emission intensity at 580 nm and remarkable decrease in fluorescence emission intensity at 488 nm, and the fluorescence color also changed from yellow to pink. Furthermore, the detection limit of the probe L, LZn towards Zn2+, Al3+ were 1.25 × 10?7 M and 3.179 × 10?6 M, respectively. Additionally, the complexation properties of L towards Zn2+ and LZn towards Al3+ were studied in detail.
- Pang, Bing-jie,Li, Chao-rui,Yang, Zheng-yin
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- Synthesis, characterization, cytotoxic activity and DNA binding Ni(II) complex with the 6-hydroxy chromone-3-carbaldehyde thiosemicarbazone
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A new ligand L, 6-hydroxy chromone-3-carbaldehyde thiosemicarbazone, and its Ni(II) complex have been synthesized and characterized. The crystal structure of Ni(II) complex was determined by single crystal X-ray diffraction. Ni(II) complex and ligand L were subjected to biological tests in vitro using THP-1, Raji and Hela cancer cell lines. Compared with the ligand, Ni(II) complex showed significant cytotoxic activity against these three cancer cell lines. The interactions of Ni(II) complex and ligand L with calf thymus DNA were then investigated by spectrometric titration, ethidium bromide displacement experiments and viscosity measurements methods. The experimental results indicated that Ni(II) complex bound to DNA by intercalative mode via the ligand L. The intrinsic binding constants of Ni(II) complex and ligand L with DNA were (1.10 ± 0.65) × 106 M-1 and (1.48 ± 0.57) × 105 M-1, respectively.
- Wang, Bao-dui,Yang, Zheng-Yin,Lü, Ming-hua,Hai, Jun,Wang, Qin,Chen, Zhong-Ning
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- Acetylation by Keten of Phenols supported on Solid Adsorbents
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Even hindered phenols, when adsorbed on solids such as silica gel and alumina, add to keten without heating or sulphuric acid catalyst.
- Chihara, Teiji,Teratani, Shousuke,Ogawa, Haruo
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- Arbutin synthase, a novel member of the NRD1β glycosyltransferase family, is a unique multifunctional enzyme converting various natural products and xenobiotics
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Plant glucosyltransferases (GTs) play a crucial role in natural product biosynthesis and metabolization of xenobiotics. We expressed the arbutin synthase (AS) cDNA from Rauvolfia serpentina cell suspension cultures in Escherichia coli with a 6xHis tag and purified the active enzyme to homogeneity. The recombinant enzyme had a temperature optimum of 50°C and showed two different pH optima (4.5 and 6.8 or 7.5, depending on the buffer). Out of 74 natural and synthetic phenols and two cinnamyl alcohols tested as substrates for the AS, 45 were accepted, covering a broad range of structural features. Converting rates comparable to hydroquinone were not achieved. In contrast to this broad acceptor substrate specificity, only pyrimidine nucleotide activated glucose was tolerated as a donor substrate. Nucleotide and amino acid sequence analysis revealed AS to be a new member of the NRD1β family of glycosyl transferases and placed the enzyme into the group of plant secondary product GTs. Arbutin synthase is therefore the first example of a broad spectrum multifunctional glucosyltransferase.
- Hefner, Tobias,Arend, Joachim,Warzecha, Heribert,Siems, Karsten,St?ckigt, Joachim
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- A Chromone-Derived Schiff-Base Ligand as Al3+ "turn on" Fluorescent Sensor: Synthesis and Spectroscopic Properties
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In this study, a novel chromone-derived Schiff-base ligand called 6-Hydroxy-3-formylchromone (2′-furan formyl) hydrazone (HCFH) has been designed and synthesized as a "turn on" fluorescent sensor for Al3+. This sensor HCFH showed high selectivity and sensitivity towards Al3+ over other metal ions investigated, and most metal ions had nearly no influences on the fluorescence response of HCFH to Al3+. Additionally, the significant enhancement by about 171-fold in fluorescence emission intensity at 502 nm was observed in the presence of Al3+ in ethanol, and it was due to the chelation-enhanced fluorescence (CHEF) effect upon complexation of HCFH with Al3+ which inhibited the photoinduced electron transfer (PET) phenomenon from the Schiff-base nitrogen atom to chromone group. Moreover, this sensor formed a 1: 1 complex with Al3+ and the fluorescence response of HCFH to Al3+ was nearly completed within 1 min. Thus, this sensor HCFH could be used to detect and recognize Al3+ for real-time detection.
- Li, Chao-Rui,Qin, Jing-Can,Wang, Bao-Dui,Fan, Long,Yan, Jun,Yang, Zheng-Yin
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- Method for promoting acylation of amine or alcohol by carbon dioxide
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The invention relates to a method for promoting acylation of amine or alcohol by carbon dioxide, which comprises the following steps of: mixing an amine compound, carboxylate or thiocarboxylate compound and a reaction solvent under the action of carbon dioxide, and reacting to obtain an amide compound, or under the action of carbon dioxide, mixing the alcohol compound, the thiocarboxylate compound and the reaction solvent [gamma]-valerolactone, and reacting to obtain the ester compound. According to the invention, under the promotion action of carbon dioxide, carboxylate or thiocarboxylate is used as an acylation reagent, and amine and alcohol are converted into amide and ester compounds in the absence of a transition metal catalyst, so that acylation reagents such as acyl chloride or anhydride with irritation and corrosivity are avoided; and the method has the advantages of simple operation, mild reaction conditions, high tolerance of substrate functional groups, strong applicability and high yield, and provides an efficient, reliable and economical preparation method for synthesis of amide and ester compounds.
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Paragraph 0034-0035
(2021/05/29)
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- Direct Acetoxylation of Arenes
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Acetoxylation of arenes is an important reaction and an unmet need in chemistry. We report a metal-free, direct acetoxylation reaction using sodium nitrate under an anhydrous environment of trifluoroacetic acid, acetic acid, and acetic anhydride. Arenes (31 examples), with oxidation potentials (Eox, in V vs SCE) lower than benzene (2.48 V), were acetoxylated with good yields and regioselectivity. A stepwise, single electron-transfer mechanism is proposed.
- Hong Nguyen, Thi Anh,Hou, Duen-Ren
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supporting information
p. 8127 - 8131
(2021/08/23)
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- Production device of liquid crystal polymer precursor acetylated monomer
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The utility model provides a production device of a liquid crystal polymer precursor acetylated monomer, which comprises a raw material dissolving tank, a micro-mixer, a micro-channel reactor and a receiving system which are sequentially communicated through pipelines along the material flow direction. By adopting the microchannel reactor, the heat exchange capability of the reactor in the reaction process is enhanced, the defect of large temperature fluctuation of the phenolic hydroxyl-containing aromatic compound in the acetylation reaction process by adopting the traditional method is overcome, the high selectivity of the reaction is realized by accurately controlling the temperature, the generation of by-products is reduced, and the production cost is reduced. The purity of the monomeris improved, a high-purity polymerized monomer is provided for the subsequent melt polycondensation reaction, and the performance of the liquid crystal polymer prepared by the polycondensation reaction is greatly improved.
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Paragraph 0102-0107
(2021/03/24)
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- An efficient method to prepare aryl acetates by the carbonylation of aryl methyl ethers or phenols
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Synthesis of valuable chemicals from lignin based compounds is critical for the application of biomass. Here, we develop a method of preparing aryl acetates by the carbonylation of aryl methyl ethers or phenols under low CO pressure. Good to excellent yields of aryl acetates were obtained using different substrates, and a possible reaction mechanism was proposed by conducting a series of control experiments. This method may provide a potential way for the utilization of lignin.
- Zhang, Dejin,Yang, Guoqiang,Xiong, Junping,Liu, Jia,Hu, Xingbang,Zhang, Zhibing
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p. 2683 - 2687
(2021/02/16)
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- A chromone derivative as a colorimetric and “ON-OFF-ON” fluorescent probe for highly sensitive and selective detection of Cu2+ and S2?
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A chromone derivative (L) which could be utilized for reversibly detecting Cu2+ and S2? by means of fluorescence quenching and displacement in aqueous solution was designed and developed. Upon the addition of Cu2+, the strong blue-green fluorescence emission of L was quenched rapidly and then recovered in 1 min by successively adding S2?. Furthermore, with the alternate addition of Cu2+ and S2?, the reversible cycles could be repeated for at least four times, which meant that L could be identified as a renewable dual-functioning probe. What's more, due to its excellent sensing performances, this probe L could also be used to detect Cu2+ and S2? with test strips conveniently.
- Liu, Cong,Tian, Limei,Liu, Kui,Xue, Jia,Fan, Long,Li, Tianrong,Yang, Zheng-yin
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- 4-Imidazol-1-yl-butane-1-sulfonic acid ionic liquid: Synthesis, structural analysis, physical properties and catalytic application as dual solvent-catalyst
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4-Imidazol-1-yl-butane-1-sulfonic acid (ImBu-SO3H) has been successfully synthetized and fully characterized by FT-IR and high-resolution NMR spectroscopy (1H, 13C). The “plausible” alternative structures of ImBu-SO3H were discussed on the basis of its NMR data. The ionic liquid showed interesting dual solvent-catalyst property, which was studied experimentally for the acetylation of a variety of functionalized alcohols, phenols, thiols, amines and α-tocopherol (α-CTP) as the most active form of vitamin E with acetic anhydride and which provided good yields within a short reaction time. ImBu-SO3H was successfully recycled by product extraction with an average recovered yield of 82% for 5 subsequent runs. The catalytic activity of the recycled ImBu-SO3H showed almost no loss even after five consecutive runs.
- Khaligh, Nader Ghaffari,Mihankhah, Taraneh,Johan, Mohd Rafie,Juan, Joon Ching
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p. 866 - 878
(2019/07/12)
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- Unprecedented acetylation of phenols using a catalytic amount of magnesium powder
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The acetylation of phenols with acetic anhydride was achieved using a catalytic amount of magnesium metal powder under air and solvent-free conditions to afford corresponding phenyl acetates in excellent yield (up to 98%).
- Bajracharya, Gan B.,Shrestha, Suryaman Sama
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supporting information
p. 1688 - 1693
(2018/06/15)
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- Design, synthesis and docking study of pyridine and thieno[2,3-b] pyridine derivatives as anticancer PIM-1 kinase inhibitors
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A series of pyridine and thieno[2,3-b]pyridine derivatives have been designed and synthesized as anticancer PIM-1 kinase inhibitors. Thirty-seven compounds were selected by NCI to be tested initially at a single dose (10 μM) in the full NCI 60 cell line panel. Compound 5b showed potent anticancer activity and was tested twice in the five-dose assay which confirmed its potent antitumor activity (GI50 values 0.302–3.57 μM) against all tested tumor cell lines except six cell lines where they showed moderate sensitivity. This compound was sent to NCI biological evaluation committee and still under consideration for further testing. In addition, the most active anticancer compounds in each series, 5b, 8d, 10c, 13h, and 15e, were evaluated for their PIM-1 kinase inhibitory activity. Compound 8d was the most potent one with IC50 = 0.019 μM followed by 5b, 15e, 10c and 13h with IC50 values 0.044, 0.083, 0.128 and 0.479 μM respectively. Moreover, docking study of the most active compounds in PIM-1 kinase active site was consistent with the in vitro activity.
- Abdelaziz, Marwa E.,El-Miligy, Mostafa M.M.,Fahmy, Salwa M.,Mahran, Mona A.,Hazzaa, Aly A.
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p. 674 - 692
(2018/08/02)
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- Practical and efficient synthesis of hydroxyaryl ketones catalyzed by HF@SiO2 under solvent-free condition
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A wide variety of hydroxyaryl ketones bearing different motifs was successfully synthesized with good yields and excellent selectivities in the presence of HF@SiO2 as an environmental friendly acid under solvent-free condition. Mild and green reaction conditions and excellent yields (50-91%) make this method an attractive method for the efficient synthesis of hydroxyaryl ketones. Fries rearrangement of phenyl benzoate in the presence of HF@SiO2 led to p-hydroxybenzophenone, while phenyl acetate in the same conditions produced o-hydroxyacetophenone as a single isomer.
- Paghandeh, Hossein,Saeidian, Hamid,Ghaffarzadeh, Mohammad
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p. 809 - 814
(2018/09/26)
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- A hydroquinone derivatives of synthetic method (by machine translation)
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The invention discloses a hydroquinone derivatives 2, 5 - dihydroxy hydroquinone synthetic method, in order to hydroquinone as the starting material, after the acylation, rearrangement, a Friedel-crafts reaction to obtain the target compound, this compound is an important intermediate synthesis of natural pigment. (by machine translation)
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Paragraph 0025; 0026
(2017/07/19)
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- Beta2-receptorexcitant and preparation method and application thereof
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The invention relates to a following formula I showed compound in a free form, a salt form or a solvated form and having a beta2-receptor exciting effect. II and III are contained in R1, Ar are following formula groups IV and V, definition of R1, R2, R3, R4, R5, R6, R7, R8, R9, R10, R13, R14, R15, R16, m and o is shown in the description. The invention further relates to a preparation method of the compound and application of a compound serving as a drug, in particular to treatment of diseases such as a chronic obstructive pulmonary disease, asthma and heart failure the aspects of a respiratory and cardiovascular system and a cardiovascular system.
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Paragraph 0101; 0102; 0103
(2017/08/25)
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- Size-selective catalysts in five functionalized porous coordination polymers with unsaturated zinc centers
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The five reported structural isomorphic porous coordination polymers (PCPs) 1-5, namely, [Zn(L)(ip) (1), Zn(L)(aip) (2), Zn(L)(hip) (3), Zn(L)(nip) (4), and Zn(L)(HBTC) (5) (L = N4,N4′-di(pyridine-4-yl)biphenyl-4,4′-dicarboxamide, H2ip = isophthalic acid, H2aip = 5-aminoisophthalic acid, H2hip = 5-hydroxyisophthalic acid, H2nip = 5-nitroisophthalic acid, H3BTC = 1,3,5-benzenetricarboxylic acid)] were used to catalyze the acetylation of phenol. All these heterogeneous catalysts exhibit good catalytic efficiency and size-selectivity toward the acetylation of phenols owing to their unsaturated metal centers, non-coordinated amide, and suitable channel size and shape. Among them, 2 displays the highest catalytic activity and excellent cooperative catalysis due to the presence of basic non-coordinated amide groups.
- Deng, Dongsheng,Guo, Hui,Ji, Baoming,Wang, Weizhou,Ma, Lufang,Luo, Feng
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p. 12611 - 12616
(2017/11/06)
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- Highly efficient and recyclable acetylation of phenols and alcohols by nickel zirconium phosphate under solvent-free conditions
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Nickel zirconium phosphate nanoparticles have been used as an efficient catalyst for the acetylation of a wide range of alcohols and phenols with acetic anhydride in good to excellent yields under solvent-free conditions. The steric and electronic properties of the different substrates had a significant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively coupled plasma optical emission spectroscopy, X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and transmission electron microscopy. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity.
- Hajipour, Abdol Reza,Karimi, Hirbod,Kohi, Afshin
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- Graphite oxide-catalyzed acetylation of alcohols and phenols
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Graphite oxide (GO) was used as a catalyst for the reactions of alcohols and phenols with acetic anhydride. The acetates of primary and secondary alcohols were prepared in good to excellent yields in short reaction time under mild conditions. Electron deficient phenols could be converted to the corresponding acetates steadily. As an efficient catalyst, GO is easily available, cheap, moderately toxic and weakly acidic.
- Liu, Yuan-Yuan,Qi, Jun-Mei,Bai, Li-Sha,Xu, Yue-Long,Ma, Ning,Sun, Fei-Fei
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supporting information
p. 726 - 730
(2016/05/19)
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- Preparation, characterization and application of RHA/TiO2 nanocomposites in the acetylation of alcohols, phenols and amines
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In this work, anatase-phase nano-titania was prepared by embedding in rice husk ash, and identified using a variety of techniques. The obtained nanocomposite (RHA/TiO2) was used as a green and inexpensive catalyst for the promotion of the acetylation of alcohols, phenols and amines with Ac2O at room temperature under solvent free conditions. The procedure gave the products in excellent yields during all reaction times. Also this catalyst can be reused for several times without loss of its catalytic activity.
- Seddighi, Mohadeseh,Shirini, Farhad,Goli-Jolodar, Omid
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p. 1003 - 1010
(2016/08/08)
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- The first vinyl acetate mediated organocatalytic transesterification of phenols: A step towards sustainability
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The present report outlines our efforts toward a simple yet elegant protocol for O-acylation of a wide variety of phenols. This highly enabling and solventless method relies on vinyl acetate as an innocuous acyl donor and DABCO as an organocatalyst. Operational simplicity, excellent yields, higher and faster conversion rates without excess reagents, a simple workup and essentially no need of columns are some of the salient features of the reported protocol.
- Kumar, Manoj,Bagchi, Sourav,Sharma, Anuj
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supporting information
p. 8329 - 8336
(2015/11/10)
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- Acetylation of alcohols and phenols under solvent-free conditions using iron zirconium phosphate
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Iron zirconium phosphate (ZPFe) nanoparticles were found to function as an efficient catalyst for the acetylation of a wide range of alcohols and phenols using acetic anhydride, generating good to excellent yields under solvent-free conditions. The steric and electronic properties of various substrates had a significant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively coupled plasma-optical emission spectrometry, X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and transmission electron microscopy. These analyses revealed that the interlayer distance in the catalyst increased from 7.5 to 9.3 ? when Fe3+ was intercalated between the layers, whereas the crystallinity of the material was reduced. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity. This new method for the acetylation of alcohols and phenols has several important advantages, including mild and environmentally friendly reaction conditions, as well as good to excellent yields and a facile work-up.
- Hajipour, Abdol R.,Karimi, Hirbod,Masti, Amir
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p. 595 - 602
(2015/09/28)
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- Catalytic application of fluorous silica gel in Fries rearrangement
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Commercially available fluorous silica gel (Fluoro Flash) with no further post-modification was successfully investigated and applied merely as a catalyst in Fries rearrangement of various aryl esters under solvent free conditions in 4 h and optimized temperatures. In addition to good yields and recyclability of the catalyst, toxicity of reaction medium, by-products, and wastes were minimized. Also, low catalyst loading was another advantage of this methodology.
- Ghaffarzadeh, Mohammad,Ahmadi, Maryam
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- Acetylation of alcohols and phenols by zinc zirconium phosphate as an efficient heterogeneous catalyst under solvent-free conditions
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An efficient method for the acetylation of a wide range of alcohols as well as phenols with acetic anhydride in good to excellent yields under solvent-free conditions, using zinc zirconium phosphate as the catalyst was investigated. The catalyst was characterized by XRD, inductivity coupled plasma-optical emission spectroscopy, and scanning electron microscope. Products are easily isolated and the protocol is mild and green, compared to the existing methods. Graphical abstract: [Figure not available: see fulltext.]
- Hajipour, Abdol Reza,Karimi, Hirbod,Karimzadeh, Morteza
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p. 1461 - 1472
(2014/09/30)
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- Rice husk ash: A new, cheap, efficient, and reusable reagent for the protection of alcohols, phenols, amines, and thiols
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Amild, efficient, and eco-friendly protocol for the protection of alcohols and phenols as trimethylsilyl ethers has been developed using rice husk ash as a reagent. This reagent is also able to catalyze the acetylation of alcohols, phenols, thiols, and amines with acetic anhydride. All reactions were performed under mild conditions in good to high yields. Copyright
- Shirini,Akbari-Dadamahaleh, Somayeh,Mohammad-Khah, Ali
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p. 577 - 586
(2014/06/09)
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- Acetylation of alcohols and phenols under solvent-free conditions using copper zirconium phosphate
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Copper zirconium phosphate nanoparticles have been used as an efficient catalyst for the acetylation of a wide range of alcohols and phenols with acetic anhydride in good to excellent yields under solvent-free conditions. The steric and electronic properties of the different substrates had a significant influence on the reaction conditions required to achieve the acetylation. The catalyst used in the current study was characterized by inductively-coupled plasma optical emission spectroscopy, energy dispersive spectroscopy, X-ray diffraction, N2 adsorption-desorption, scanning electron microscopy, and transmission electron microscopy. These analyses revealed that the interlayer distance in the catalyst increased from 7.5 to 8.0 ? when Cu2+ was intercalated between the layers, whereas the crystallinity of the material was reduced. This nanocatalyst could also be recovered and reused at least six times without any discernible decrease in its catalytic activity. This new method for the acetylation of alcohols and phenols has several key advantages, including mild and environmentally friendly reaction conditions, as well as good to excellent yields and a facile work-up.
- Hajipour, Abdol R.,Karimi, Hirbod
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p. 1982 - 1989
(2015/09/28)
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- Rice husk: Introduction of a green, cheap and reusable catalyst for the protection of alcohols, phenols, amines and thiols
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A mild, efficient and eco-friendly protocol for the chemoselective protection of benzylic and primary and less hindered secondary aliphatic alcohols and phenols as trimethylsilyl ethers and different types of amines as N-tert-butylcarbamates is developed using rice husk (RiH) as the catalyst. This reagent is also able to catalyze the acetylation of alcohols, phenols, thiols and amines with acetic anhydride. Easy work-up, relatively short reaction times, excellent yields and low cost, availability and reusability of the catalyst are the striking features of this methodology, which can be considered to be one of the best and general methods for the protection of alcohols, phenols, thiols and amines. In addition, the use of a green reagent in the above-mentioned reactions results in a reduction of environmental pollution and of the cost of the applied methods.
- Shirini, Farhad,Akbari-Dadamahaleh, Somayeh,Mohammad-Khah, Ali,Aliakbar, Ali-Reza
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p. 164 - 170
(2014/03/21)
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- Preparation and characterization of multi-walled carbon nanotubes (MWCNTs), functionalized with phosphonic acid (MWCNTs-C-PO3H2) and its application as a novel, efficient, heterogeneous, highly selective and reusable catalyst for acetylation of alcohols, phenols, aromatic amines, and thiols
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A novel, efficient, heterogeneous, and reusable multi-walled carbon nanotubes (MWCNTs), functionalized with phosphonic acid (MWCNTs-C-PO 3H2) has been synthesized. The synthesized CNTs were characterized using some electron microscopic techniques such as scanning electron microscopy (SEM), atomic force microscopy (AFM), Energy dispersive X-ray spectroscopy (EDAX), and also some thermal and spectroscopic methods such as thermogravimetry (TG). The nitrogen adsorption behavior of the MWCNTs-C-PO3H2 catalyst was evaluated using the TG instrumentation system at 25°C. The catalyst was applied successfully for highly efficient and selective acetylation of alcohols, phenols, thiols and aromatic amines with acetic anhydride at room temperature under solvent-free conditions. The reusability of the catalyst was checked and the recovered catalyst was reused for five runs without significant loss in activity.
- Dehghani, Farzaneh,Sardarian, Ali Reza,Doroodmand, Mohammad Mehdi
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p. 673 - 684
(2014/05/20)
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- Lewis basic ionic liquid as an efficient and facile catalyst for acetylation of alcohols, phenols, and amines under solvent-free conditions
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The Lewis basic ionic liquid 1,8-diazabicyclo[5.4.0]undec-7-en-8-ium acetate was employed for the acetylation of various phenols, alcohols, and amines in good-to-excellent yields at 50 C under solvent-free conditions in a short time. Compared with existing methods based on conventional catalysts and toxic solvents, the reported method is simple, mild and environmentally viable. Furthermore, the ionic liquid was conveniently separated from the products and easily recycled to catalyze other acetylation reactions with excellent yields. .
- Ji, Li,Qian, Chao,Chen, Xin-Zhi
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p. 369 - 374
(2013/05/21)
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- Poly(N-vinylimidazole) as an efficient catalyst for acetylation of alcohols, phenols, thiols and amines under solvent-free conditions
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Poly(N-vinylimidazole) is able to promote instantaneous quantitative acetylation of a variety of functionalized alcohols, phenols, thiols and amines with acetic anhydride at room temperature under solvent-free conditions. This new method consistently has excellent yields and the catalyst can be reused and recovered several times. Furthermore, the reaction can even be carried out on a larger scale. The Royal Society of Chemistry.
- Khaligh, Nader Ghaffari
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- A succinimide-N-sulfonic acid catalyst for acetylation reactions in absence of a solvent
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A small amount of succinimide-N-sulfonic acid efficiently catalyzed the acetylation of a variety alcohols, phenols, thiols, amines and aldehydes with acetic anhydride at room temperature under solvent free conditions. This catalyst has the advantages of excellent yields and short reaction times and the reaction can be carried out on a large scale, which makes it potentially useful for industrial applications.
- Shirini, Farhad,Khaligh, Nader Ghaffari
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p. 695 - 703
(2013/08/25)
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- Solvent-free acetylation and tetrahydropyranylation of alcohols catalyzed by recyclable sulfonated ordered nanostructured carbon
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Rapid and practical green acetylation and tetrahydropyranylation routes of structurally diverse alcohols and phenols were applied under solvent-free reaction conditions providing excellent yields, using catalytic amounts of environmentally friendly sulfonated ordered nanoporous carbon (CMK-5-SO 3H). Non-toxic nature of the catalyst, its easy handling, recovery and reusability, and the absence of any solvent characterize the presented procedures as efficient methods. These procedures provide methods for the separation of the product by simple filtration.
- Zareyee, Daryoush,Alizadeh, Parastoo,Ghandali, Mohammad S.,Khalilzadeh, Mohammad A.
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p. 713 - 721
(2013/07/26)
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- Preparation, characterization and use of poly(4-vinylpyridinium) perchlorate as a new, efficient, and versatile solid phase catalyst for acetylation of alcohols, phenols and amines
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Poly(4-vinylpyridine) perchlorate, is a supported, recyclable, eco-benign catalyst for the reaction acetylation of structurally diverse alcohols, phenols and amines at room temperature under solvent-free conditions. The catalyst was studied by FT-IR, X-ray diffraction, Scanning Electron Microscope and Thermo-gravimetric Analyses. All the products were extensively characterized by 1H NMR, FT-IR, GC-MS and melting point analyses. The catalyst can be recovered and reused without loss of activity. The work-up of the reaction consists of a simple filtration, followed by concentration of the crude product and purification. It is important to point out that a large-scale reaction is possible using a same amount of catalyst.
- Khaligh, Nader Ghaffari
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- O-acetylation: Synthesis of acetylated phenols from aryl-methyl ethers over boron alkoxides
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A new acetylation procedure has been applied to 13 aryl-methyl ethers using boron chemistry. In this procedure, demethylation of aryl-methyl ethers and acetylation of the resulting phenols were combined into one procedure in order to shorten the number of stages and to achieve easy purification. Eleven known with/without bromine and two new [bis(3,4-diacetoxyphenyl)methanone and 5,5'-methylenebis(1,2-diacetoxy-3,4-dibromobenzene) (a natural bromophenol's acetylated derivative)] acetylated arene compounds were synthesised from their methoxy derivatives by this method. The effectiveness of the method was illustrated by producing an acetylated natural bromophenol from its methyl ether. The phenol form was obtained by hydrolysing the acetylated natural bromophenol. Thus, the advantage of this method in the natural product chemistry of phenolic compounds was confirmed.
- Balaydin, Halis T.
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scheme or table
p. 238 - 240
(2012/09/08)
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- HF-Pyridine: A versatile promoter for monoacylation/sulfonylation of phenolic diols and for direct conversion of t-butyldimethylsilyl ethers to the corresponding acetates
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Monoacylation and trifluoromethanesulfonylation of phenolic diols were achieved by the aid of HF-pyridine, whereas diacylation occurred with pyridine alone. Furthermore, HF-pyridine was found to promote the direct conversion of t-butyldimethylsilyl ethers to the corresponding acetates.
- Michigami, Kyosuke,Yoshimoto, Kazuya,Hayashi, Masahiko
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scheme or table
p. 138 - 139
(2012/03/09)
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- Highly efficient solvent-free acetylation of alcohols with acetic anhydride catalyzed by recyclable sulfonic acid catalyst (SBA-15-Ph-Pr-SO3H)- An environmentally benign method
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The catalytic activity of highly thermal stable, hydrophobic, and complete heterogeneous propylsulfonic acid functionalized nanostructured SBA-15 for excellent acetylation of alcohols and phenols with acetic anhydride at ambient temperature in solvent-free conditions was examined under environmentally benign reaction conditions. The salient features of this protocol are the absence of solvent, a green experimental procedure, and simple reusability of the catalyst (at least five reaction cycles).
- Zareyee, Daryoush,Ghadikolaee, Abdollah Razaghi,Khalilzadeh, Mohammad A.
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experimental part
p. 464 - 468
(2012/06/16)
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- New porphyrin-polyoxometalate hybrid materials: Synthesis, characterization and investigation of catalytic activity in acetylation reactions
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New hybrid complexes based on covalent interaction between 5,10,15,20-tetrakis(4-aminophenyl)porphyrinatozinc(ii) and 5,10,15,20- tetrakis(4-aminophenyl)porphyrinatotin(iv) chloride, and a Lindqvist-type polyoxometalate, Mo6O192-, were prepared. These new porphyrin-polyoxometalate hybrid materials were characterized by 1H NMR, FT IR and UV-Vis spectroscopic methods and cyclic voltammetry. These spectro- and electrochemical studies provided several spectral data for synthesis of these compounds. Cyclic voltammetry showed the influence of the polyoxometalate on the redox process of the porphyrin ring. The catalytic activity of tin(iv)porphyrin-hexamolybdate hybrid material was investigated in the acetylation of alcohols and phenols with acetic anhydride. The reusability of this catalyst was also investigated.
- Araghi, Mehdi,Mirkhani, Valiollah,Moghadam, Majid,Tangestaninejad, Shahram,Mohammdpoor-Baltork, Iraj
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p. 11745 - 11752
(2013/02/23)
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- Novel double-SO3h functionalized ionic liquid for acetylation
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Novel double-SO3H functionalized ionic liquid (DFIL) was synthesized and its catalytic activities for acetylation studied. The result showed that the DFIL possess high acidity and was very efficient for the acetylation of alcohols, amines and phenols with good to excellent yields in short reaction times. Operational simplicity, stability to water and air, small amounts needed, low cost, high yields, high acidity, applicability to large-scale reactions and reusability are the key features of the DFIL, which indicated promising applications of DFIL in green chemical processes. Pleiades Publishing, Ltd., 2012.
- Zhu, Lili,Liang, Xuezheng
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p. 684 - 688
(2013/02/23)
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- Amorphous carbon-silica composites bearing sulfonic acid as solid acid catalysts for the chemoselective protection of aldehydes as 1,1-diacetates and for N-, O- and S-acylations
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Amorphous carbon-silica composites bearing sulfonic acid derived from inexpensive natural organic compounds (glucose, maltose, cellulose, chitosan and starch) were prepared by partial carbonization followed by sulfonation and their catalytic activity was evaluated for the protection of aldehydes as 1,1-diacetates and for N-, O- and S-acylations under solvent-free conditions. Different biomaterials have been chosen, with a view to select the most active solid acid catalyst. Carbon-silica composites were characterized by FTIR, XRD and elemental analysis. Sulfonated carbon-silica composite derived from starch was found to be the most active and could be recycled for several runs without loss of significant activity. It was also characterized by TGA, SEM and TEM.
- Gupta, Princy,Paul, Satya
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experimental part
p. 2365 - 2372
(2011/10/31)
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- Highly efficient and versatile acetylation of alcohols, phenols and amines catalyzed by methylenediphosphonic acid (MDP) under solvent-free conditions
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Methylenediphosphonic Acid (MDP) was found to be a simple, cheap and reusable heterogeneous catalyst for the acetylation of structurally diverse alcohols, phenols and amines with acetic anhydride under solvent-free conditions at room temperature. This method showed preferential selectivity for the acetylation of the amino group in the presence of hydroxyl group. The method is very mild and the yields were in excellent.
- Xie, Minhao,Wang, Hongyong,Wu, Jun,He, Yongjun,Liu, Yaling,Zou, Pei
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experimental part
p. 884 - 886
(2012/04/23)
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- Synthesis and biological evaluation of new flavonoid fatty acid esters with anti-adipogenic and enhancing glucose consumption activities
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Oleoyl Formononetin (OF) has good weight loss activity and hypolipidemic activity, could improve insulin sensitivity and suppress adipogenesis. To acquire better biological activities, three series of flavonoid fatty acid esters were designed and synthesized by optimizing the structure of OF. Their bioactivities were assayed in vitro. Some of these novel compounds could effectively inhibit preadipocyte proliferation and adipogenesis. Moreover, they could enhance glucose consumption in adipocytes notably.
- Zhao, Wei,Sun, Jie,Xiang, Hua,Zeng, Yan-Yan,Li, Xiao-Bo,Xiao, Hong,Chen, De-Ying,Ma, Ren-Ling
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experimental part
p. 3192 - 3203
(2011/06/24)
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- Polystyrene-bound electron-deficient tin(IV) porphyrin: A new, highly efficient, robust and reusable catalyst for acetylation of alcohols and phenols with acetic anhydride
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In the present work, tetrakis(p-aminophenyl)porphyrinatotin(IV) trifluoromethanesulfonate, [SnIV(TNH2PP)(OTf) 2], supported on chloromethylated polystyrene was prepared and characterized by elemental analysis, FT IR and diffuse reflectance UV-Vis spectroscopic methods. This new heterogenized catalyst was used for acetylation of alcohols and phenols with acetic anhydride in short reaction times and high yields. The catalyst is of high reusability and stability in the acetylation reactions and was recovered several times without loss of its initial activity and catalyst leaching.
- Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj,Gharaati, Shadab
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scheme or table
p. 1080 - 1087
(2012/03/11)
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- H6GeMo10V2O40·16H 2O nanoparticles prepared by hydrothermal method: A new and reusable heteropoly acid catalyst for highly efficient acetylation of alcohols and phenols under solvent-free conditions
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A new Keggin-type heteropoly acid, namely decamolybdodivanadogermanic acid (H6GeMo10V2O40·16H 2O), with nanosized particles (5-8 nm), has been synthesized by a hydrothermal method and characterized by elemental analysis, thermogravimetric analysis (TGA), powder X-ray diffractometry (XRD), Fourier-transform infrared spectroscopy (FTIR), UV-Visible spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and potentiometric titration. H6GeMo10V2O40·16H 2O revealed high catalytic activity for acetylation of various alcohols and phenols with acetic anhydride at room temperature (298 ± 2 K) and under solvent-free conditions. The catalyst can be easily recovered and used repeatedly for five cycles with a slight loss of activity. The catalytic activity of H6GeMo10V2O40· 16H2O was higher than that of other Keggin-type heteropoly acids, such as H3PW12O40, H3PMo 12O40 and H4SiW12O40.
- Farhadi, Saeid,Zareisahamieh, Reza,Zaidi, Masoumeh
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experimental part
p. 1323 - 1332
(2012/04/04)
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- Electron-deficient [TiIV(salophen)(OTf)2]: A new and highly efficient catalyst for the acetylation of alcohols and phenols with acetic anhydride
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In the present work, a highly efficient method for acetylation of alcohols and phenols with acetic anhydride catalyzed by high-valent [Ti IV(salophen)(OTf)2] is reported. Under these conditions, primary, secondary and tertiary alcohols as well as phenols were acetylated with short reaction times and high yields. The catalyst was reused several times without loss of its catalytic activity.
- Yadegari, Maryam,Moghadam, Majid,Tangestaninejad, Shahram,Mirkhani, Valiollah,Mohammadpoor-Baltork, Iraj
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experimental part
p. 2237 - 2243
(2011/10/03)
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- Investigation of catalytic activity of high-valent vanadium(IV) tetraphenylporphyrin: A new, highly efficient and reusable catalyst for acetylation of alcohols and phenols with acetic anhydride
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In the present work, the catalytic activity of high-valent tetraphenylporphyrinatovanadium(IV) trifluoromethanesulfonate, [V IV(TPP)(OTf)2], in the acetylation of alcohols and phenols with Ac2O is reported. This new V(IV) catalyst was used as an efficient catalyst for not only primary alcohols (benzylic and aliphatic) but also sterically-hindered secondary and tertiary alcohols with acetic anhydride and the corresponding acetates were obtained in 85-99% yield and 0.5-15 min. Acetylation of phenols with acetic anhydride was also performed to afford the desired acetates in 88-99% and 1.5-20 min. This catalyst can be reused several times without loss of its catalytic activity.
- Taghavi, S. Abdolmanaf,Moghadam, Majid,Mohammadpoor-Baltork, Iraj,Tangestaninejad, Shahram,Mirkhani, Valiollah,Khosropour, Ahmad Reza
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experimental part
p. 159 - 164
(2011/12/16)
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- Synthesis of hydrazones schiff bases and microbiological evaluation of lsonicotinoyl hydrazide with different acetophenone
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A series of hydrazones Schiff bases compounds have been synthesized by reacting isonicotinoyl hydrazide with 2-hydroxy-5-chloro acetophenone, 2-hydroxy-5-methyl acetophenone, 2-hydroxy-5-carboxy acetophenone, 2,5-dihydroxy acetophenone, 2-hydroxy-5-chloro-4-methyl acetophenone, 2-hydroxy-5-chloro-3- nitro acetophenone, 2-hydroxy-5-methyl-3-nitro acetophenone and 2-hydroxy-5-bromo acetophenone. The Schiff bases have been evaluated for the antifungal and antibacterial activities.
- Kelode,Mandlik,Aswar
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scheme or table
p. 1053 - 1062
(2012/04/04)
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- Highly efficient dynamic kinetic resolution of secondary aromatic alcohols with low-cost and easily available acid resins as racemization catalysts
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A new and efficient dynamic kinetic resolution (DKR) process of secondary aromatic alcohols was developed with acid resins as racemization catalysts. Acid resin CD8604 was shown to have excellent racemization activity and good biocompatibility. When employing CD8604 and complex acyl donors as racemization catalyst and acyl donor, respectively, enantiomerically pure aromatic acetate was obtained with excellent yield and ee values through the DKR process. It is noteworthy that the system could be reused more than 10 times with little loss of yield and ee value.
- Cheng, Yongmei,Xu, Gang,Wu, Jianping,Zhang, Chensheng,Yang, Lirong
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supporting information; experimental part
p. 2366 - 2369
(2010/06/13)
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