- Effect of the Chromone Core Substitution of Dirchromone on the Resultant Biological Activities
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Dirchromone is a bioactive vinyl sulfoxide-bearing chromone first isolated from the shrub Dirca palustris. Altogether, 32 of its derivatives were prepared to assess the effect of substitution of its chromone core upon activities against cancer cell lines, Gram-positive bacteria, and fungi (such as Candida albicans). All compounds were synthesized following a synthetic strategy involving Pummerer and soft-enolization Baker-Venkataraman rearrangements. Substituent position changes induced little variability on the activities tested. There was no correlation between cytotoxic and antibacterial effects, suggesting different underlying mechanisms of action. In particular, hydroxy group and cyanide substituents diminished cytotoxicity, with the latter featuring enhanced antibacterial activity. Higher homologues of 6-alkoxydirchromones also exhibited progressively emerging antifungal activity. Other modifications had moderate effects on cytotoxicity with some derivatives leading to increased potency. This behavior highlights the robustness of the natural dirchromone pharmacophore toward decoration, thus paving the way for more elaborate future drug design.
- St-Gelais, Alexis,Alsarraf, Jér?me,Legault, Jean,Plourde, Joanne,Pichette, André
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supporting information
p. 2786 - 2794
(2021/12/02)
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- Iron-catalyzed arene C-H hydroxylation
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The sustainable, undirected, and selective catalytic hydroxylation of arenes remains an ongoing research challenge because of the relative inertness of aryl carbon-hydrogen bonds, the higher reactivity of the phenolic products leading to over-oxidized by-products, and the frequently insufficient regioselectivity. We report that iron coordinated by a bioinspired L-cystine-derived ligand can catalyze undirected arene carbon-hydrogen hydroxylation with hydrogen peroxide as the terminal oxidant. The reaction is distinguished by its broad substrate scope, excellent selectivity, and good yields, and it showcases compatibility with oxidation-sensitive functional groups, such as alcohols, polyphenols, aldehydes, and even a boronic acid. This method is well suited for the synthesis of polyphenols through multiple carbon-hydrogen hydroxylations, as well as the late-stage functionalization of natural products and drug molecules.
- Cheng, Lu,Wang, Huihui,Cai, Hengrui,Zhang, Jie,Gong, Xu,Han, Wei
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- Efficient preparation method of 2'-hydroxyacetophenone compounds
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The invention discloses an efficient preparation method of 2'-hydroxyacetophenone compounds. The method comprises the following steps: substituted phenol and acetic anhydride in a molar ratio of 1:(1-1.1) is subjected to a reaction at 130-150 DEG C in the absent of a solvent, acetic acid substituted phenyl ester as shown in the formula is generated, and acetic acid and acetic acid substituted phenyl ester are separated by rectification; prepared acetic acid substituted phenyl ester is subjected to a transposition reaction under the action of a catalyst in an organic solvent at the temperatureof 50-120 DEG C, and 2'-hydroxyacetophenone compounds as shown in the formula are generated; filtering is performed to remove the catalyst after the reaction is finished, the solvent is removed by evaporation, and the 2'-hydroxyacetophenone compounds are prepared by rectification under vacuum, wherein the catalyst is phosphomolybdic acid, phosphotungstic acid, silicotungstic acid or a mixture of the acid. The preparation method has mild conditions and simple flow, and is environmentally friendly and suitable for industrial production, selectivity is high, and ortho-position selectivity is as high as 99.5%.
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Paragraph 0034; 0035; 0037; 0038
(2019/05/08)
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- NHC-Stabilized Radicals in the Formal Hydroacylation Reaction of Alkynes
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Mechanistic details of transformations catalyzed by N-heterocyclic carbenes (NHC) are currently of great interest, targeting questions on the active catalyst in operation and the structure and reactivity of key intermediates. These mechanistic studies are
- Phan, Jenny,Ruser, Stephanie-M.,Zeitler, Kirsten,Rehbein, Julia
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supporting information
p. 557 - 561
(2018/11/23)
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- Iridium-Catalyzed C(sp3)?H Addition of Methyl Ethers across Intramolecular Carbon–Carbon Double Bonds Giving 2,3-Dihydrobenzofurans
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Intramolecular addition of an O-methyl C(sp3)?H bond across a carbon-carbon double bond occurs in the iridium-catalyzed reaction of methyl 2-(propen-2-yl)phenyl ethers. The Ir/(S)-DTBM-SEGPHOS catalyst promotes the reaction efficiently in toluene at 110–135 °C to afford 3,3-dimethyl-2,3-dihydrobenzofurans. Enantioselective C(sp3)?H addition is achieved in the reaction of methyl 2-(1-siloxyethenyl)phenyl ethers, affording enantioenriched 3-hydroxy-2,3-dihydrobenzofuran derivatives with up to 96% ee. (Figure presented.).
- Ohmura, Toshimichi,Kusaka, Satoshi,Torigoe, Takeru,Suginome, Michinori
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supporting information
p. 4448 - 4453
(2019/09/16)
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- Preparation technology of 1-(2-hydroxy-3-methoxyphenyl)ethanone
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The invention discloses a preparation technology of 1-(2-hydroxy-3-methoxyphenyl)ethanone. Through protecting group addition, alkylation, oxidation and deprotection, 1-(2-hydroxy-3-methoxyphenyl)ethanone is prepared from o-vanillin as a raw material. The
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- MCM-41-supported phosphotungstic acid-catalyzed cleavage of C-O bond in allyl aryl ethers
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Removal of the protecting allyl group from allyl aryl ethers in the presence of other oxygen protecting groups was successfully achieved using a solid acid supported on the high surface area material MCM-41. The catalyst showed excellent activity in the presence of various electron withdrawing, electron donating, and oxidizable functional groups. The methodology is also very useful for the removal of protecting allyl groups of various natural products such as vanillin, isovanillin, and other oxygen functionalized aldehydes and ketones.
- Sakate, Sachin S.,Kamble, Sumit B.,Chikate, Rajeev C.,Rode, Chandrashekhar V.
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p. 4943 - 4949
(2017/07/12)
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- COMPOUNDS, COMPOSITIONS, AND METHODS FOR MODULATING CFTR
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The present disclosure is directed to disclosed compounds that modulate, e.g., address underlying defects in cellular processing of CFTR activity.
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Paragraph 0287
(2017/08/01)
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- Synthesis and biological evaluation of phenoxyacetic acid derivatives as novel free fatty acid receptor 1 agonists
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Free fatty acid receptor 1 (FFA1) is a new potential drug target for the treatment of type 2 diabetes because of its role in amplifying glucose-stimulated insulin secretion in pancreatic β-cell. In the present studies, we identified phenoxyacetic acid derivative (18b) as a potent FFA1 agonist (EC50 = 62.3 nM) based on the structure of phenylpropanoic acid derivative 4p. Moreover, compound 18b could significantly improve oral glucose tolerance in ICR mice and dose-dependently reduced glucose levels in type 2 diabetic C57BL/6 mice without observation of hypoglycemic side effect. Additionally, compound 18b exhibited acceptable PK profiles. In summary, compound 18b with ideal PK profiles exhibited good activity in vitro and in vivo, and might be a promising drug candidate for the treatment of diabetes mellitus.
- Wang, Xuekun,Zhao, Tianxiao,Yang, Baowei,Li, Zheng,Cui, Jian,Dai, Yuxuan,Qiu, Qianqian,Qiang, Hao,Huang, Wenlong,Qian, Hai
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p. 132 - 140
(2015/02/18)
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- Lithiation of a silyl ether: Formation of an ortho-fries hydroxyketone
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A hydroxy-directed alkylation of an N,N-diethylarylamide using CIPE-assisted α-silyl carbanions (CIPE=complex-induced proximity effect) has been developed using a simple reagent combination of LDA (lithium diisopropylamide) and chlorosilane. A study of the mechanism, and the application of the procedure to an anionic Snieckus-Fries rearrangement for a highly efficient synthesis of the potent phosphatidylinositol 3-kinase (PI3K) inhibitor LY294002, are reported.
- Lo, Hong-Jay,Lin, Chin-Yin,Tseng, Mei-Chun,Chein, Rong-Jie
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p. 9026 - 9029
(2014/09/17)
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- A facile demethylation of ortho substituted aryl methyl ethers promoted by AlCl3
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An efficient and practical demethylation of ortho substituted aryl methyl ethers using AlCl3 has been developed. This method gives a high conversion, is simple to operate and is cost-effective. A mechanism involving the complexation of AlCl3 with the OMe and the adjacent electron withdrawing group is proposed. Many functional groups can be tolerated in the demethylation process, and 29 examples gave a demethylated product in a yield of 90-98%.
- Du, Zhen-Ting,Lu, Jing,Yu, Hong-Rui,Xu, Yan,Li, An-Pai
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experimental part
p. 222 - 227
(2010/08/04)
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- Synthesis of methoxy-substituted phenols by peracid oxidation of the aromatic ring
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A novel benign protocol for the preparation of hydroxy-methoxybenzene derivatives is disclosed. By utilizing this protocol, activated aromatic compounds such as l,3-dimethoxy-2-methyl-benzene and 1-(2,6-dimethoxyphenyl) ethanone are smoothly converted to the corresponding monohydroxylated compound. The reaction can be considered to be a normal aromatic electrophilic substitution reaction, and the regioselectivity for the reaction thus follows the similar rules as for electrophilic substitutions. The protocol is composed by benign reagents, namely, hydogenperoxide, acetic acid, and p-toluene sulfonic acid, which lead to the production of ethaneperoxoic acid in situ. The ethaneperoxoic acid operates as the hydroxylating reagent. The hydroxylation reaction is completed within a short period and requires moreover only mild experimental conditions, which make this novel protocol a green, cheap, and rapid process leading to hydroxy-methoxybenzene derivatives. The proposed reaction mechanism is supported by density functional theory and NMR spectroscopy experiments. The mechanism is constituted by two discrete steps: (a) addition of OH+ to the most nucleophilic carbon atom of the aromatic ring, which is the rate-determining step, and (b) the loss of the proton from the aromatic ring.
- Bjorsvik, Hans-Rene,Occhipinti, Giovanni,Gambarotti, Cristian,Cerasino, Leonardo,Jensen, Vidar R.
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p. 7290 - 7296
(2007/10/03)
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- Preparative monohydroxyflavanone syntheses and a protocol for gas chromatography-mass spectrometry analysis of monohydroxyflavanones
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We describe a facile efficient, and preparative approach for monohydroxyflavanone syntheses. Using this protocol, a hydroxyl is regio-selectively introduced at one carbon of a flavanone A- or B-ring per synthesis. The seven possible isomers were each synthesized from the corresponding monomethoxymethoxylated 2′-hydroxychalcones in acidic solution. These monohydroxyflavanones were characterized using a gas chromatography-mass spectrometry (GC-MS) system that incorporated a DB-5 capillary column. Ours is the first report of a preparative synthetic method during which a single hydroxyl can be selectively added to a flavanone A- or B-ring at any position. We are also the first to develop a procedure that separates the seven isomers by GC and characterizes the mass spectra of the isomers. Both the synthetic method and the GC-MS conditions may become important tools during future flavanone metabolism and oxidation studies.
- Kagawa, Hitoshi,Shigematsu, Asako,Ohta, Shigeru,Harigaya, Yoshihiro
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p. 547 - 554
(2007/10/03)
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- Use of chromans
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The invention relates to the use of 2-[4-({[(2R)-8-isopropoxy-chroman-2-yl]-methyl}amino)butyl]-1,2-benzisothiazol-3(2H)-one 1,1-dioxide, its physiologically acceptable salts, hydrates and/or solvates, in particular its hydrochloride, for the production o
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- 4-phenoxycoumarins as herbicidal agents
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There are provided methods to control mono-cotyledenous weed species in the presence of crops and particularly in the presence of cereal crops. Also provided are 4-(2,6-disubstituted-phenoxy)coumarin derivatives useful as herbicidal agents and methods to
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- 4-Phenoxycoumarins as herbicidal agents
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There are provided methods to control monocotyledenous weed species in the presence of crops and particularly in the presence of cereal crops. Also provided are 4-(2,6-disubstituted-phenoxy)coumarin derivatives useful as herbicidal agents and methods to p
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- 8,2'-DIHYDROXYFLAVONE FROM PRIMULA PULVERULENTA
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A novel flavone, isolated from the farinose exudate of Primula pulverulenta, was identified as 8,2'-dihydroxyflavone.This is the first naturally occurring flavone, in which ring A is oxygenated only at C-8.The structure was deduced from spectral comparisons with the structurally related flavones: 5,2'-, 3,2'- and 2',3'-dihydroxyflavone and confirmed by total synthesis.The spectral properties of other flavones oxygenation with a simple pattern are discussed in relation to 8,2'-dihydroxyflavone.Key Word Index - Primula pulverulenta; Primulaceae; farinose excretion; 8,2'-dihydroxyflavone; 8,2'-dimethoxyflavone.
- Wollenweber, Eckhard,Mann, Karin,Iinuma, Munekazu,Tanaka, Toshiyuki,Mizuno, Mizuo
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p. 1483 - 1486
(2007/10/02)
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