- Non-plasmonic Ni nanoparticles catalyzed visible light selective hydrogenolysis of aryl ethers in lignin under mild conditions
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Light-driven catalysis on catalytically versatile group VIII metals, which has been widely used in thermal catalysis, holds great potential in solar-to-chemical conversion. We report a novel photocatalysis process for the selective hydrogenolysis of aryl ethers in lignin on a heterogeneous catalyst of non-precious Ni nanoparticles supported on ZrO2. Three aryl ether bonds in lignin were successfully cleaved under mild conditions with excellent conversion and good to excellent selectivity under visible light irradiation. We also used solar irradiation to demonstrate a significant reduction in the total energy consumption. The light irradiation excited interband transitions in Ni nanoparticles and the resultant energetic electrons enhanced the activity of reductive cleavage of the aryl ethers. Its application potential was illustrated by the depolymerization of dealkaline lignin to give a total monomer yield of 9.84 wt% with vanillin, guaiacol, and apocynin as the three major products.
- Baeyens, Jan,Li, Peifeng,Ouyang, Yixuan,Sarina, Sarina,Su, Haijia,Xiao, Gang,Zhao, Yilin,Zhu, Huai-Yong
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supporting information
p. 7780 - 7789
(2021/10/12)
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- Alpha,beta-unsaturated ketone derivatives, preparation method of derivatives and application of derivatives as medicines
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The invention relates to the technical field of medicine, and proposes alpha,beta-unsaturated ketone derivatives and a preparation method thereof. The derivatives have a structural general formula represented by a formula I shown in the specification, whe
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Paragraph 0171-0173; 0177-0178
(2019/12/15)
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- Unambiguous Identification of β-Tubulin as the Direct Cellular Target Responsible for the Cytotoxicity of Chalcone by Photoaffinity Labeling
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Chalcone is a simple and potentially privileged structure in medicinal chemistry with a diverse repertoire of biological activities, among which cytotoxicity is of particular interest. The sharp structure–activity relationship (SAR) for chalcone's cytotoxicity suggests structure-specific target interactions. Despite the numerous putative targets proposed, evidence for direct target interactions in cells is unavailable. In this study, guided by the sharp cytotoxic SAR, we developed a cytotoxic chalcone-based photoaffinity labeling (PAL) probe, (E)-3-(3-azidophenyl)-1-[3,5-dimethoxy-4-(prop-2-yn-1-yloxy)phenyl]-2-methylprop-2-en-1-one (C95; IC50: 0.38±0.01 μm), along with two structurally similar non-cytotoxic probes. These probes were used to search for the direct cellular target responsible for chalcone's cytotoxicity through intact cell-based PAL experiments, in which β-tubulin was identified to specifically interact with the cytotoxic probe (i.e., C95) but not the non-cytotoxic probes. A set of phenotypical and biochemical assays further reinforced β-tubulin as the cytotoxic target of chalcones. Peptide mass quantitation by mass spectrometric analysis revealed one peptide potentially labeled by C95, providing information on chalcone's binding site on β-tubulin.
- Zhou, Bo,Yu, Xingxin,Zhuang, Chunlin,Villalta, Peter,Lin, Yong,Lu, Junxuan,Xing, Chengguo
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supporting information
p. 1436 - 1445
(2016/07/16)
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- Isolation of functionalized phenolic monomers through selective oxidation and CO bond cleavage of the β-O-4 linkages in Lignin
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Functionalized phenolic monomers have been generated and isolated from an organosolv lignin through a two-step depolymerization process. Chemoselective catalytic oxidation of β-O-4 linkages promoted by the DDQ/tBuONO/ O2 system was achieved in model compounds, including polymeric models and in real lignin. The oxidized β-O-4 linkages were then cleaved on reaction with zinc. Compared to many existing methods, this protocol, which can be achieved in one pot, is highly selective, giving rise to a simple mixture of products that can be readily purified to give pure compounds. The functionality present in these products makes them potentially valuable building blocks.
- Lancefield, Christopher S.,Ojo, O. Stephen,Tran, Fanny,Westwood, Nicholas J.
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supporting information
p. 258 - 262
(2015/02/19)
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- Cu(OAc)2-catalyzed remote benzylic C(sp3)-H oxyfunctionalization for C=O formation directed by the hindered para-hydroxyl group with ambient air as the terminal oxidant under ligand- and additive-free conditions
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A hindered para-hydroxyl group-directed remote benzylic C(sp3)-H oxyfunctionalization has been developed for the straightforward transformation of 2,6-disubstituted 4-cresols, 4-alkylphenols, 4-hydroxybenzyl alcohols and 4-hydroxybenzyl alkyl ethers into various aromatic carbonyl compounds. The ligand- and additive-free Cu(OAc)2-catalyzed atmospheric oxidation mediated by ethylene glycol unlocks a facile, atom-economical, and environmentally benign C=O formation for the functionalization of primary and secondary benzyl groups. Due to the pharmaceutical importance of 4-hydroxybenzaldehydes and 4-hydroxyphenones, the methodology is expected to be of significant value for both fundamental research and practical applications.
- Jiang, Jian-An,Chen, Cheng,Huang, Jian-Gang,Liu, Hong-Wei,Cao, Song,Ji, Ya-Fei
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supporting information
p. 1248 - 1254
(2014/03/21)
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- DEPOLYMERIZATION OF LIGNIN USING SOLID ACID CATALYSTS
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The invention provides for a process for the depolymerization of lignin in an inert atmosphere to result in substituted phenolic monomer compounds. The process is catalysed by heterogeneous solid acid catalysts and is carried out in batch or continuous mode.
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Page/Page column 6; 7
(2012/12/13)
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- Selective methoxy ether cleavage of 2,6-dimethoxyphenol followed by a selective acylation
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A Friedel-Crafts reaction of 2,6-dimethoxyphenol in the presence of aluminum chloride and propanoyl or butanoyl chloride, respectively, lead, at elevated temperatures, to a selective cleavage of one of the methoxy groups followed by a selective acylation
- Adogla, Enoch A.,Janser, Romy F.J.,Fairbanks, Samuel S.,Vortolomei, Caitlyn M.,Meka, Ranjith K.,Janser, Ingo
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experimental part
p. 11 - 14
(2012/01/14)
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- Ethacrynic acid analogues lacking the α,β-unsaturated carbonyl unit-Potential anti-metastatic drugs
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A series of ethacrynic acid analogues, lacking the α,β-unsaturated carbonyl unit, was synthesized and subsequently evaluated for their ability to inhibit the migration of human breast cancer cells, MCF-7/AZ. Several of the analogues were already active in the low micromolar range, whereas ethacrynic acid itself shows no potential to inhibit the migration of these cancer cells. Preliminary studies show that the presence of one or more methoxy groups at the phenyl ring of ethacrynic acid is important in order for the ethacrynic acid analogues to demonstrate an inhibitory effect on the migration.
- Janser, Romy F.J.,Meka, Ranjith K.,Bryant, Zack E.,Adogla, Enoch A.,Vogel, Elizabeth K.,Wharton, Jaimie L.,Tilley, Cynthia M.,Kaminski, Catherine N.,Ferrey, Seth L.,Van slambrouck, Severine,Steelant, Wim F.A.,Janser, Ingo
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experimental part
p. 1848 - 1850
(2010/07/06)
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- Determination of methoxyphenols in ambient atmospheric particulate matter: Tracers for wood combustion
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Combustion of wood and other biomass fuels produces source-specific organic compounds arising from pyrolysis of lignin, including substantial amounts of 4-substituted methoxylated phenolic compounds (methoxyphenols). These compounds have been used as atmospheric markers to determine the contribution of wood smoke to ambient atmospheric fine particulate matter (PM). However, reliable quantification of methoxyphenols represents an analytical challenge because these compounds are polar, semivolatile, and somewhat reactive. We report herein an improved gas chromatographic-mass spectrometric (GC/MS) method for the sensitive and reliable determination of methoxyphenols in low-volume ambient PM samples. Deuterated standard compounds are added to the environmental samples prior to extraction to determine analyte recoveries in each sample. Analytical figures of merit for the assay, as applied to ambient PM2.5 and PM10 samples are as follows: recovery = 63-100%; precision = 2-6%; analytical limit of detection (S/N 2) = 0.002 μg/mL; limit of quantitation = 0.07-0.45 ng/m3 (assuming a 14 m3 sample). The improved method was applied to ambient PM samples collected between 1999 and 2000 in Seattle, WA. Particle-bound methoxyphenol concentrations in the range 3 were observed and the methoxyphenols were present almost exclusively in the fine (PM2.5) size fraction. We also demonstrated that XRF analysis of samples of atmospheric PM collected on Teflon filters significantly reduced the levels of methoxyphenols measured in the PM samples in subsequent assay of the same filters. Therefore, XRF analysis of filters, commonly undertaken to obtain trace element concentrations for use in source apportionment analyses, would preclude the subsequent analysis of those filters for methoxyphenols and other similarly semivolatile or reactive organic chemicals.
- Simpson, Christopher D.,Paulsen, Michael,Dills, Russell L.,Liu, L.-J. Sally,Kalman, David A.
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p. 631 - 637
(2007/10/03)
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- Quinone Dehydrogenation. Oxidation of Benzylic Alcohols with 2,3-Dichloro-5,6-dicyanobenzoquinone
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2,3-Dichloro-5,6-dicyanobenzoquinone (DDQ) reacts with primary and secondary aryl-substituted alcohols under mild conditions in dioxane solution to give the corresponding carbonyl compounds in high yields.In contrast to other oxidants, DDQ can be applied advantageously for the oxidation of hydroxyaryl-substituted alcohols.A mechanism involving participation of the phenolic hydroxyl group in the dehydrogenation reaction is discussed.Oxidations of hydroxyaryl-substituted alcohols by DDQ in methanolsolution resulting in the formation of benzoquinones by loss of the hydroxyaryl side chain are interpreted in terms of phenol oxidation.An example of a pyridine-catalyzed Smiles rearrangement of an o-hydroxy-substituted diphenyl ether is reported.
- Becker, Hans-Dieter,Bjoerk, Anders,Adler, Erich
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p. 1596 - 1600
(2007/10/02)
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