- 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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- Site-Specific Oxidation of (sp3)C-C(sp3)/H Bonds by NaNO2/HCl
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A site-specific oxidation of (sp3)C-C(sp3) and (sp3)C-H bonds in aryl alkanes by the use of NaNO2/HCl was explored. The method is chemical-oxidant-free, transition-metal-free, uses water as the solvent, and proceeds under mild conditions, making it valuable and attractive to synthetic organic chemistry.
- Zhao, Jianyou,Shen, Tong,Sun, Zhihui,Wang, Nengyong,Yang, Le,Wu, Jintao,You, Huichao,Liu, Zhong-Quan
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supporting information
p. 4057 - 4061
(2021/05/26)
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- 2, 4-diaminopyrimidine compound containing phenol fragment, preparation method, pharmaceutical compositions and use thereof
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The invention discloses a 2, 4-diaminopyrimidine compound containing phenol fragment with a general formula I shown in the specification, pharmaceutically acceptable salts or pharmaceutically acceptable solvates, a preparation method thereof, pharmaceutical compositions containing the compounds, and use of the compounds in preparation of drugs for preventing or treating anaplastic lymphoma kinaserelated abnormal cell proliferation, morphological changes, hyperkinesia and other associated diseases in organisms, and angiogenesis or cancerometastasis associated diseases, especially use in drugsfor treating or preventing tumor growth and metastasis.
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Paragraph 0144-0147
(2018/04/02)
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- Design, synthesis and docking studies of novel thienopyrimidine derivatives bearing chromone moiety as mTOR/PI3Kα inhibitors
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Two series of thienopyrimidine derivatives (10a-k, 16a-j) bearing chromone moiety were designed and synthesized. All the compounds were evaluated for inhibitory activity against mTOR kinase at a concentration of 10uM. Four selected compounds were further evaluated for the IC50 values against mTOR kinase, PI3Kα kinase and two cancer cell lines. Some of the target compounds exhibited moderate to excellent mTOR/PI3Kα kinase inhibitory activity and cytotoxicity. The most promising compound 16i showed good inhibitory activity against mTOR/PI3Kα kinase and good antitumor potency for H460 and PC-3 cell lines with IC50 values of 0.16 ± 0.03 μM, 2.35 ± 0.19 μM, 1.20 ± 0.23 μM and 0.85 ± 0.04 μM, which were 8.6, >5, 7.9 and 19.1 times more active than compound I (1.37 ± 0.07 μM, >10 μM, 9.52 ± 0.29 μM, 16.27 ± 0.54 μM), respectively. Structure-activity relationships (SARs) and docking studies indicated that the chromone moiety is necessary for the potent antitumor activity and cytotoxicity of these compounds. Substitution of the chromone moiety at the 6-position has a significant impact to the inhibitory activity, in particular a carboxylic acid group, produced the best potency.
- Zhu, Wufu,Chen, Chen,Sun, Chengyu,Xu, Shan,Wu, Chunjiang,Lei, Fei,Xia, Hui,Tu, Qidong,Zheng, Pengwu
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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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- 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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- Design and syntheses of novel N′-((4-oxo-4H-chromen-3-yl)methylene) benzohydrazide as inhibitors of cyanobacterial fructose-1,6-/sedoheptulose-1,7- bisphosphatase
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Cyanobacterial fructose-1,6-/sedoheptulose-1,7-bisphoshatase (Cy-FBP/SBPase) is an important target enzyme for finding inhibitors to solve harmful algal bloom (HAB). In this study, as potential inhibitors of Cy-FBP/SBPase, a series of novel chromone-connecting benzohydrazone compounds (Novel N′-((4-oxo-4H-chromen-3-yl)methylene)benzohydrazide) were designed and synthesized. Their inhibitory activities against Cy-FBP/SBPase were further examined in vitro. Some of these compounds, such as f6-f8, f11, f12 and f16, exhibit higher inhibitory activities (IC50 = 11.2-16.1 μM), especially, the compound f7 was identified as the most potent inhibitor with IC50 value of 11.2 μM. The probable binding-mode of compound f7 was further analyzed carefully by molecular docking methods. These results indicate that compound f7 could be used as a lead compound for further optimization and might have potential to be developed as a new algicide.
- Tu, Qi-Dong,Li, Ding,Sun, Yao,Han, Xin-Ya,Yi, Fan,Sha, Yibamu,Ren, Yan-Liang,Ding, Ming-Wu,Feng, Ling-Ling,Wan, Jian
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p. 2826 - 2831
(2013/06/27)
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- O-acylation of substituted phenols with various alkanoyl chlorides under phase-transfer catalyst conditions
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Esterification of several types of mono-and disubstituted phenols with various mono-and dialkanoyl chlorides was performed in phase-transfer catalysis conditions, using tetrabutylammonium chloride in a mixture of aqueous NaOH and dichloromethane. The process is particularly efficient (almost quantitative yields) as well as rapid (only 5 min reaction time, at a temperature of0°C). Taylor & Francis Group, LLC.
- Simion, Alina Marieta,Hashimoto, Iwao,Mitoma, Yoshiharu,Egashira, Naoyoshi,Simion, Cristian
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experimental part
p. 921 - 931
(2012/02/01)
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- New synthetic flavone derivatives induce apoptosis of hepatocarcinoma cells
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Natural flavonoids have broad biological activity, including anticancer. In this study, a series of novel flavone derivatives were synthesized with the substitutions of chlorine, isopropyl, methoxy, and nitro groups on the benzene ring of flavone skeleton to develop effective anticancer agents. Antiproliferative assays showed that the synthesized chemicals possess notable activity against hepatocarcinoma cells (HepG-2); in particular, the compound 6f with chlorine and dimethoxy modifications at the two benzene rings showed an IC50 at 1.1 μM to HepG-2. The 6f also displayed marked anticancer activity towards a panel of cancer cells, including nasopharyngeal carcinoma cells (CNE-2 and CNE-1), breast adenocarcinoma cell (MCF-7), and epithelial carcinoma cells (Hela). Exposing HepG-2 cells to compound 6f at 10 μM induced chromatin condensation, nuclear disassembly, and DNA fragmentation. In 6f-treated HepG-2 cells, the sub-G0 population was remarkably increased; and in these cells, both caspase-8 and caspase-9 activity was significantly increased, which in turn activated caspase-3. In addition, proapoptotic Bax was upregulated by compound 6f while the antiapoptotic Bcl-2 was downregulated. Taken together, our data suggest that the new flavonoid derivative 6f triggers apoptosis through both death-receptor and mitochondria-dependent intrinsic pathways, being a potent therapeutic agent against hepatocarcinoma.
- Liu, Huachen,Dong, Aijun,Gao, Chunmei,Tan, Chunyan,Xie, Zhenhua,Zu, Xuyu,Qu, Long,Jiang, Yuyang
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experimental part
p. 6322 - 6328
(2010/10/03)
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- Counterattack mode differential acetylative deprotection of phenylmethyl ethers: Applications to solid phase organic reactions
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A counterattack protocol for differential acetylative cleavage of phenylmethyl ether has been developed. The phenylmethyl moiety is liberated as benzyl bromide that is isolated and reused providing advantages in terms of waste minimization/utilization and atom economy. The applicability of this methodology has been extended for solid phase organic reactions with the feasibility of reuse of the solid support.
- Chakraborti, Asit K.,Chankeshwara, Sunay V.
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experimental part
p. 1367 - 1370
(2009/07/04)
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- Phosphomolybdic acid: Mild and efficient catalyst for acetylation of alcohols, phenols, and amines under solvent-free conditions
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Phosphomolybdic acid (PMA) has been found to be a simple and efficient catalyst for the acetylation of alcohols, phenols, and amines. Acetylation reactions with acetic anhydride (1.0 equiv) proceed in excellent yield in the presence of a catalytic amount (0.2 mol%) of PMA at ambient temperature within a relatively short reaction time (10 min). Structurally diverse alcohols, phenols, and amines undergo acetylation under solvent-free conditions. Georg Thieme Verlag Stuttgart.
- Kadam, Santosh T.,Sung, Soo Kim
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p. 267 - 271
(2008/12/22)
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- O-acylation mechanism of p-substituted phenols with various alkanoyl chlorides under phase transfer catalysis conditions
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The phenolic ester synthesis between equimolecular amounts of phenols and various alkanoyl chlorides in the presence of aqueous sodium hydroxide solution in a two-phase system (20 mL of each 10% NaOH and dicloromethane, respectively) was reinvestigated under PTC conditions (10 mmol of tetrabutyl ammonium chloride, BNC). The esterification was complete within several minutes and the obtained ester was in high purity. For example, phenyl acetate was obtained quantitatively at 0°C in 5 minutes using a stoichiometric amount of BNC. This acylation procedure is technically simple and does not require anhydrous conditions. A bimolecular electrophilic attack of alkanoyl chloride against the ion-pair in the organic phase, which was formed between the quaternary ammonium cation and the phenoxide anion, must be a rate-determining step, because a plot of the logarithm of relative rate constants of various alkanoyl chlorides vs Taft's polar substituents constants (taking into account the steric constants, Es) gave a good linear relationship. We have found a simple, rapid, convenient, easily separating and efficient PTC technique to synthesize phenolic esters.
- Hashimoto, Iwao,Kawaji, Takatoshi,Mitoma, Yoshiharu,Simion, Alina M.,Semion, Cristian,Ishimoto, Keiko,Prakash, G.K. Surya,Olah, George A.,Tashiro, Masashi
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p. 149 - 155
(2007/10/03)
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- Formylchromone derivatives as a novel class of protein tyrosine phosphatase 1B inhibitors
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Formylchromone inhibits a human protein tyrosine phosphatase PTP1B with a IC50 value of 73 μM. The chemical reactivity of formylchromone was adjusted by substitution at various positions of the formylchromone skeleton. In an initial assessment of the structure-activity relationship, the most potent inhibitor showed an IC50 of 4.3 μM against PTP1B and strong or medium selectivity against other human PTPases, LAR and TC-PTP. This compound, however, was not selective against microbial PTPases, YPTP1 and YOP. The potency and selectivity of the formylchromone derivatives expecting further improvements provides a novel pharmacophore for the design of drugs for the treatmenrt of type 2 diabetes and obesity.
- Shim, Yi Sup,Kim, Ki Chul,Chi, Dae Yoon,Lee, Keun-Hyeung,Cho, Hyeongjin
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p. 2561 - 2563
(2007/10/03)
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- Acetylation of phenols in organic solvent catalyzed by a lipase from chromobacterium viscosum
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Lipase from Chromobacterium viscosum, absorbed on an inert support, was employed as catalyst for the esterification of monohydric phenols in organic solvent, with vinyl acetate as acyl donor. The effect of aromatic ring substitution on the initial rate of transesterification was investigated.
- Nicolosi,Piatelli,Sanfilippo
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p. 2477 - 2482
(2007/10/02)
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- Substituent Effect in o-Nitroperbenzoic Acid Oxidation of m- and p-Substituted Acetophenones
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The Baeyer-Villiger reaction of m- and p-substituted acetophenones (substituents: H, p-MeO, p-t-Bu, p-i-Pr, p-Et, p-Me, p-Cl, p-Br, m-MeO, m-Me, m-Cl) with o-nitroperbenzoic acid was studied in chloroform at 30 deg C.The rate constants for the general acid catalysis were measured at several concentrations of o-nitrobenzoic acid which acted as an acid catalyst.The uncatalyzed and acid-catalyzed rate constants obtained afforded ρ values of -2.16 and -4.11 with ?, respectively.The results indicated that the rate-determining step is the migration of the phenyl group in the peroxy acid-carbonyl adduct for all the substituents studied, whether the reaction is acid-catalyzed or not, and that the acid catalyst intervenes only in the formation of the acid-ketone adduct in the initial state and not in the migration step.The variation of the leaving group abilities required the variation of the substituent constants applied, whereas the acid intervention in the addition step was reflected only in the variation of the ρ value, not in the substituent constants to be applied.The smaller resonance demand for o-nitrobenzoic acid indicated that the structure of the transition state in the migration step was looser and that the position of the transition state was earlier than those for m-chloroperbenzoic acid.
- Token, Katsuo,Hirano, Kenji,Yokoyama, Tai,Goto, Katsumi
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p. 2766 - 2771
(2007/10/02)
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- OXYGENATION OF AROMATIC AND ALIPHATIC HYDROCARBONS BY A NEW REAGENT SYSTEM, Fe(CH3CN)6(2+)-H2O2-Ac2O: AN EFFECTIVE MODEL REAGENT FOR MONO-OXYGENASE
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Reactions of aromatic and aliphatic hydrocarbons with a new system, Fe(CH3CN)6(2+) - H2O2 - Ac2O in CH3CN, gave oxygenation products with fairly high reaction efficiency ( Tables I and II )compared to known to reagent systems used as enzyme models for mono-oxygenases.Investigations of the mechanism of these reactions indicated the involvement of either complex C.FeIV(OH)(OAc)(2+), or complex D, FeIV(OAc)(2+), dependig on the organic substrate.Keywords-oxygenation; aromatic hydrocarbon; aliphatic hydrocarbon; hexakisacetonitrile iron(II) perchlorate; hydrogen peroxide; enzyme model; mono-oxygenase
- Kotani, Eiichi,Kobayashi. Shigeki,Ishii, Yoko,Tobinaga, Seisho
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p. 4671 - 4679
(2007/10/02)
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