- Pharmaceutical characterization of myonovin, a novel skeletal muscle regenerator: In silico, in vitro and in vivo studies
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PURPOSE: MyoNovin is a novel skeletal muscle-regenerating compound developed through synthesis of two nitro groups onto a guaifenesin backbone to deliver nitric oxide to skeletal muscle with a potential to treat muscle atrophy. The purpose of this study was to utilize in silico, in vitro, and in vivo approaches to characterize MyoNovin and examine its safety, biodistribution, and feasibility for drug delivery. METHODS: In silico software packages were used to predict the physicochemical and biopharmaceutical properties of MyoNovin. In vitro cardiotoxicity was assessed using human cardiomyocytes (RL-14) while effects on CYP3A4 metabolic enzyme and antioxidant activity were examined using commercial kits. A novel HPLC assay was developed to measure MyoNovin concentration in serum, and delineate initial pharmacokinetic and acute toxicity after intravenous administration (20 mg/kg) to male Sprague-Dawley rats. RESULTS: MyoNovin showed relatively high lipophilicity with a LogP value of 3.49, a 20-fold higher skin permeability (19.89 cm/s*107) compared to guaifenesin (0.66 cm/s*107), and ~10-fold higher effective jejunal permeability (2.24 cm/s*104) compared to guaifenesin (0.26 cm/s*104). In vitro, MyoNovin was not cytotoxic to cardiomyocytes at concentrations below 8 μM and did not inhibit CYP3A4 or show antioxidant activity. In vivo, MyoNovin had a short half-life (t1/2) of 0.16 h, and a volume of distribution Vss of 0.62 L/kg. Biomarkers of MyoNovin cardiac and renal toxicity did not differ significantly from baseline control levels. CONCLUSIONS: The predicted high lipophilicity and skin permeability of MyoNovin render it a potential candidate for transdermal administration while its favourable intestinal permeation suggests it may be suitable for oral administration. Pharmacokinetics following IV administration of MyoNovin were delineated for the first time in a rat model. Preliminary single 20 mg/kg dose assessment of MyoNovin suggest no influence on cardiac troponin or β-N-Acetylglucosaminidase.
- Alrushaid, Samaa,Davies, Neal M.,Anderson, Judy E.,Le, Tyson,Yá?ez, Jaime A.,Maayah, Zaid H.,El-Kadi, Ayman O. S.,Rachid, Ousama,Sayre, Casey L.,L?benberg, Raimar,Burczynski, Frank J.
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Read Online
- Synthesis and First-Time Assessment of o-Eugenol Derivatives against Mycobacterium tuberculosis
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In this work, we report the first-time assessment of o-eugenol, 6-allyl-2-methoxyphenol, and their selected derivatives, against Mycobacterium tuberculosis H37RV, using the MABA susceptibility test. The bromo, nitro, O-alkylated, and reduced derivatives were obtained by standard methods and were characterized by spectroscopic and mass spectral data. Structure–activity relationships were investigated, with the most active derivatives being 4,5-dibromo-2-methoxy-6-propylphenol (139 μM) and 2-methoxy-3-nitro-6-propylphenol (237 μM). This study provides important information on the rational design of new lead anti-TB drugs based on o-eugenol derivatives.
- Moraes, Adriana Marques,da Silva, Emerson Teixeira,Wardell, James L.,de Souza, Marcus V. N.
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Read Online
- Nickel-catalyzed deallylation of aryl allyl ethers with hydrosilanes
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An efficient and mild catalytic deallylation method of aryl allyl ethers is developed, with commercially available Ni(COD)2 as catalyst precursor, simple substituted bipyridine as ligand and air-stable hydrosilanes. The process is compatible with a variety of functional groups and the desired phenol products can be obtained with excellent yields and selectivity. Besides, by detection or isolation of key intermediates, mechanism studies confirm that the deallylation undergoes η3-allylnickel intermediate pathway.
- Ding, Guangni,Fan, Sijie,Wang, Jingyang,Wang, Yu,Wu, Xiaoyu,Xie, Xiaomin,Yang, Liqun,Zhang, Zhaoguo
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supporting information
(2021/09/28)
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- Nickel Hydride Catalyzed Cleavage of Allyl Ethers Induced by Isomerization
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This report discloses the deallylation of O - and N -allyl functional groups by using a combination of a Ni-H precatalyst and excess Bronsted acid. Key steps are the isomerization of the O - or N -allyl group through Ni-catalyzed double-bond migration followed by Bronsted acid induced O/N-C bond hydrolysis. A variety of functional groups are tolerated in this protocol, highlighting its synthetic value.
- Kathe, Prasad M.,Berkefeld, Andreas,Fleischer, Ivana
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supporting information
p. 1629 - 1632
(2021/02/09)
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- Enantioselective Construction of Si-Stereogenic Center via Rhodium-Catalyzed Intermolecular Hydrosilylation of Alkene
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Catalytic, enantioselective synthesis of stereogenic silicon compounds remains a challenge. Herein, we report a rhodium-catalyzed regio- and enantio-selective intermolecular hydrosilylation of alkene with prochiral dihydrosilane. This new method features a simple catalytic system, mild reaction conditions and a wide functional group tolerance.
- He, Tao,Liu, Li-Chuan,Ma, Wen-Peng,Li, Bin,Zhang, Qing-Wei,He, Wei
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supporting information
p. 17011 - 17015
(2020/11/30)
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- Subsupercritical Water Generated by Inductive Heating Inside Flow Reactors Facilitates the Claisen Rearrangement
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Claisen rearrangement of electron-deficient O-allylated phenols, including fluorine-modified phenols, is facilitated in aqueous media at high temperatures and pressures under flow conditions, as opposed to organic solvents. The O-allylation of phenols can be coupled with the Claisen rearrangement in an integrated flow system.
- Oltmanns, Mona,Kirschning, Andreas
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supporting information
p. 1942 - 1946
(2020/11/13)
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- Semisynthetic Phenol Derivatives Obtained from Natural Phenols: Antimicrobial Activity and Molecular Properties
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Semisynthetic phenol derivatives were obtained from the natural phenols: thymol, carvacrol, eugenol, and guaiacol through catalytic oxychlorination, Williamson synthesis, and aromatic Claisen rearrangement. The compounds characterization was carried out by 1H NMR, 13C NMR, and mass spectrometry. The natural phenols and their semisynthetic derivatives were tested for their antimicrobial activity against the bacteria: Staphylococcus aureus, Escherichia coli, Listeria innocua, Pseudomonas aeruginosa, Salmonella enterica Typhimurium, Salmonella enterica ssp. enterica, and Bacillus cereus. Minimum inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) values were determined using concentrations from 220 to 3.44 μg mL-1. Most of the tested compounds presented MIC values ≤220 μg mL-1 for all the bacteria used in the assays. The molecular properties of the compounds were computed with the PM6 method. Through principle components analysis, the natural phenols and their semisynthetic derivatives with higher antimicrobial potential were grouped.
- Pinheiro, Patrícia Fontes,Menini, Luciana Alves Parreira,Bernardes, Patrícia Campos,Saraiva, Sérgio Henriques,Carneiro, José Walkimar Mesquita,Costa, Adilson Vidal,Arruda, Társila Rodrigues,Lage, Mateus Ribeiro,Gon?alves, Patrícia Martins,Bernardes, Carolina De Oliveira,Alvarenga, Elson Santiago,Menini, Luciano
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p. 323 - 330
(2018/01/17)
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- Palladium-Catalyzed Fluoroalkylative Cyclization of Olefins
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A palladium-catalyzed fluoroalkylative cyclization of olefins with readily available Rf-I reagents to afford the corresponding fluoroalkylated 2,3-dihydrobenzofuran and indolin derivatives with moderate to excellent yields is reported. This novel procedure provides an efficient method for the construction of Csp3-CF2 and C-O/N bonds in one step. A wide range of functional groups are tolerated. It is proposed that a radical/SET (single electron transfer) pathway proceeding via the fluoroalkyl radical may be involved in the catalytic cycle.
- Liao, Jianhua,Fan, Lianfeng,Guo, Wei,Zhang, Zhenming,Li, Jiawei,Zhu, Chuanle,Ren, Yanwei,Wu, Wanqing,Jiang, Huanfeng
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supporting information
p. 1008 - 1011
(2017/03/15)
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- Highly efficient Tsuji-Trost allylation in water catalyzed by Pd-nanoparticles
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Palladium nanoparticles stabilized by poly(vinylpyrrolidone) catalyze Tsuji-Trost allylations in water with very high turnover numbers. The di-allylation of methylene active compounds and the allylation of bio-based phenols was performed in high yield. The allylation of lignin showed a high selectivity towards the phenolic OH groups.
- Llevot,Monney,Sehlinger,Behrens,Meier
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supporting information
p. 5175 - 5178
(2017/07/12)
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- Boosting effect of ortho-propenyl substituent on the antioxidant activity of natural phenols
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Seven new antioxidants derived from natural or synthetic phenols have been designed as alternatives to BHT and BHA antioxidants. Influence of various substituents at the ortho, meta and para positions of the aromatic core of phenols on the bond dissociation enthalpy of the ArO-H bond was evaluated using a DFT method B3LYP/6-311++G(2d,2p)//B3LYP/6-311G(d,p). This prediction highlighted the ortho-propenyl group as the best substituent to decrease the bond dissociation enthalpy (BDE) value. The rate constants of hydrogen transfer from these phenols to DPPH radical in a non-polar and non-protic solvent have been measured and were found to be in agreement with the BDE calculations. For o-propenyl derivatives from 2-tert-butyl-4-methylphenol, BHA, creosol, isoeugenol and di-o-propenyl p-cresol, fewer radicals were trapped by a single phenol molecule, i.e. a lower stoichiometric number. Reaction mechanisms involving the evolution of the primary phenoxyl radical ArO are proposed to rationalise these effects.
- Marteau, Clémentine,Guitard, Romain,Penverne, Christophe,Favier, Dominique,Nardello-Rataj, Véronique,Aubry, Jean-Marie
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supporting information
p. 418 - 427
(2015/10/19)
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- O-eugenol: A versatile molecule for production of polyfunctional alkenes via organometallic catalysis
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In this study, the synthesis and cross metathesis of o-eugenol (2-allyl-6-methoxy phenol) has been investigated. Synthesis was conducted through two stages of reaction. The first step in the synthetic procedure was to obtain the intermediate 1-but-3-enyl-2-methoxy benzene. Then the heating of the obtained intermediate will initiate will initiate a [3,3] sigmatropic rearrangement to give the o-eugenol with a good yield. The ruthenium-catalyzed cross-metathesis of o-eugenol derivatives with electron deficient olefins including methyl acrylate, acrylonitrile and acrylamides was also reported. In addition the polymerization of 1-allyl-2-(allyloxy)-3-methoxybenzene was possible by acyclic diene metathesis and this allowed to synthesize a polymer from a natural substrate. All the resulting structures were supported by the spectroscopic data.
- Al-Ayed, Abdullah Sulaiman,Hamdi, Naceur,Peruzzini, Maurizio
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p. 960 - 964
(2016/03/01)
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- Regioselective Alkoxycarbonylation of Allyl Phenyl Ethers Catalyzed by Pd/dppb under Syngas Conditions
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A simple and regioselective synthesis of phenoxy esters and phenylthio esters is reported. The products are obtained by selective alkoxycarbonylation catalyzed by Pd2(dba)3, 1,4-bis(diphenylphisphino)butane (dppb), and syngas (CO/H2) in chloroform/alcohol. This methodology affords bifunctional products in good yield with excellent n-selectivity and without the need to use additives.
- Amézquita-Valencia, Manuel,Alper, Howard
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p. 3860 - 3867
(2016/05/24)
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- A diastereoselective route to trans-2-aryl-2,3-dihydrobenzofurans through sequential cross-metathesis/isomerization/allylboration reactions: Synthesis of bioactive neolignans
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A new highly diastereoselective synthetic route to trans-2,3-dihydrobenzofuran systems, in particular those bearing an aryl substituent at the C2 position, is described. The cornerstone of our strategy is the implementation of a cross-metathesis/isomerization/allylboration sequence starting from 2-allyl-substituted phenols and aldehydes. After an intramolecular Mitsunobu cyclization step, the anti-homoallylic alcohols allow the synthesis of the desired skeleton in a stereoselective fashion. As an illustration, we used this strategy for the preparation of the dihydrodehydrodiconiferyl alcohol (1a), a natural dihydrobenzofuran neolignan, as well as for a formal synthesis of its O-demethylated derivative 1b. An enantioselective version of this approach employing a chiral phosphoric acid in the allylboration step is also studied.
- Hemelaere, Rémy,Carreaux, Fran?ois,Carboni, Bertrand
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supporting information
p. 2470 - 2481
(2015/04/22)
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- Structure-activity relationships in the domain of odorants having marine notes
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Continuing our investigations into marine note odorants, we herein describe several new scaffolds. Among them, 2,3-dihydrobenzofuran-2-carbaldehyde is particularly interesting. The results demonstrate that the seven-membered ring with a ketone functional group of the Calone 1951 family can be replaced by a five-membered ring carrying an aldehydefunction. In addition, this work has allowed us to discover the valuable 2-methoxy-4-methylphenyl methyl carbonate (20b), which is very close to vanillin, and 2-methoxy-2,4-dimethyl-1,3-benzodioxole (29d), which belongs to the isoeugenol/dihydroeugenol olfactive family.
- Gaudin, Jean-Marc,De Saint Laumer, Jean-Yves
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p. 1437 - 1447
(2015/03/04)
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- PdI2-catalyzed regioselective cyclocarbonylation of 2-allyl phenols to dihydrocoumarins
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A simple, efficient, and regioselective synthesis of 3-methyl-3,4-dihydrocoumarins is reported. The reaction of 2-allyl phenols with synthesis gas was catalyzed by PdI2, and 1,3,5,7-tetramethyl-6-phenyl-2,4,8-trioxa-6-phosphaadamantane (L1) and 1,3,5,7-tetramethyl-6-tetradecyl-2,4,8-trioxa-6-phosphaadamantane (L2) were effective as ligands, affording good product selectivity in all cases.
- Amzquita-Valencia, Manuel,Alper, Howard
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supporting information
p. 5827 - 5829
(2015/01/08)
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- Enantioselective synthesis of benzofurans and benzoxazines via an olefin cross-metathesis-intramolecular oxo-Michael reaction
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Chiral phosphoric acid and Hoveyda-Grubbs II were found to catalyze an olefin cross-metathesis-intramolecular oxo-Michael cascade reaction of the ortho-allylphenols and enones to provide a variety of benzofuran and benzoxazine derivatives in moderate to good yields and enantioselectivity.
- Zhang, Jun-Wei,Cai, Quan,Gu, Qing,Shi, Xiao-Xin,You, Shu-Li
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supporting information
p. 7750 - 7752
(2013/09/02)
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- A new catalyst for the asymmetric Henry reaction: Synthesis of β-nitroethanols in high enantiomeric excess
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A new chiral tetrahydrosalen ligand has been designed and synthesized from cis-2,5-diaminobicyclo[2.2.2]octane. The complex generated in situ by the interaction of the ligand with (CuOTf)2·C6H 5CH3 was an efficient catalyst for the asymmetric Henry reaction, producing nitroaldol products in high yield and good stereoselectivity. Henry reactions catalyzed by this tetrahydrosalen-Cu(I) complex led to syntheses of β-adrenergic blocking agents (S)-toliprolol, (S)-moprolol, and (S)-propanolol.
- White, James D.,Shaw, Subrata
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p. 6270 - 6273
(2013/02/23)
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- Dialkoxybenzene and dialkoxyallylbenzene feeding and oviposition deterrents against the cabbage looper, trichoplusia ni: Potential insect behavior control agents
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The antifeedant, oviposition deterrent, and toxic effects of individual dialkoxybenzene compounds/sets and of hydroxy- or alkoxy-substituted allylbenzenes, obtained through Claisen rearrangement of substituted allyloxybenzenes, were assessed against the cabbage looper, Trichoplusia ni, in laboratory bioassays. Most of the compounds/sets strongly deterred larval feeding, with some exhibiting mild toxic and oviposition deterrent effects as well. Some of the compounds/sets were more active than the commercial insect repellent, DEET (N,N-diethyl-m-toluamide), as both feeding and oviposition deterrents against the cabbage looper. On the basis of the obtained oviposition data a general hypothesis was proposed regarding the oviposition sites: one binding mode with the alkyl and allyl groups on the same side of the benzene ring resulted in deterrence, the other with alkyl and allyl groups on opposite sides of the benzene ring resulted in stimulation. The results suggest some structure-activity relationships useful in improving the efficacy of the compounds and designing new, nontoxic insect control agents for agriculture.
- Akhtar, Yasmin,Yu, Yang,Isman, Murray B.,Plettner, Erika
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scheme or table
p. 4983 - 4991
(2011/08/06)
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- METHODS AND COMPOSITIONS FOR CONTROL OF CABBAGE LOOPER, Trichoplusia ni
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The invention provides in part dialkoxybenzene compounds for controlling infestation by a Trichoplusia ni, and methods thereof. The compounds include a compound of Formula I: where R1 may be methyl, ethyl, propyl, n-butyl, isopentyl(3-methylbutyl) or allyl; R2 may be at positions 2, 3 or 4 and may be H, methyl, ethyl, propyl, n-butyl, isopentyl(3-methylbutyl) or allyl; and R3 may be optionally present at positions 2, 3 and 4, and is allyl; except that when R2 is at position 2, R3 if present is at position 3, and when R2 is at position 3, R3 if present is at positions 2 or 4, and when R2 is at position 4, R3 if present is at position 2, and when R2 is at position 4 and R3, if present, has reacted with an OH group at position 1 in a Markovnikov sense, then R3 becomes R4, a dihydrofuran.
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Page/Page column 22
(2010/07/04)
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- Stereoselective construction of substituted chromans by palladium-catalyzed cyclization of propargylic carbonates with 2-(2-Hydroxyphenyl)acetates
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Highly substituted chromans have been constructed In a highly stereoselective manner by a palladium-catalyzed reaction of propargylic carbonates with 2-(2-hydroxyphenyl)acetates. Enantioselective reactions also successfully proceeded to give the optically active chromans with high enantioselectivity.
- Yoshida, Masahiro,Higuchi, Mariko,Shishido, Kozo
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supporting information; experimental part
p. 4752 - 4755
(2009/12/09)
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- NOVEL HETEROCYCLIC COMPOUNDS USEFUL FOR THE TREATMENT OF INFLAMMATORY AND ALLERGIC DISORDERS: PROCESS FOR THEIR PREPARATION AND PHARMACEUTICAL COMPOSITIONS CONTAINING THEM
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The present invention relates to novel Phosphodiesterase type 4 (PDE4) inhibitors of the formula (1) and analogs, tautomers, enantiomers, a diasteromers, regioisomers, stereoisomers, polymorphs, pharmaceutically acceptable salts, appropriate N-oxides, pharmaceutically acceptable solvates thereof and the pharmaceutical compositions containing them which are useful in the treatment of allergic and inflammatory diseases including asthma, chronic bronchitis, atopic dermatitis, urticaria, allergic rhinitis, allergic conjunctivitis, vernal conjunctivitis, eosinophilic granuloma, psoriasis, rheumatoid arthritis, septic shock, ulcerative colitis, Crohn's disease, reperfusion injury of the myocardium and reperfusion injury of the brain, chronic glomerulonephritis, endotoxic shock and adult respiratory distress syndrome.
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Page/Page column 26-27
(2009/12/24)
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- General, mild, and intermolecular Ullmann-type synthesis of diaryl and alkyl aryl ethers catalyzed by diol-copper(I) complex
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(Chemical Equation Presented) A wide range of diaryl ethers and alkyl aryl ethers are synthesized through intermolecular C(aryl)-O bond formation from the corresponding aryl iodides/aryl bromides and phenols/alcohols through Ullmann-type coupling reaction in the presence of a catalytic amount of easily available (±)-diol L3-CuI complex under very mild reaction conditions. Less reactive aryl bromides can also be used for O-arylation of phenols under the same reaction conditions without increasing the reaction temperature, catalyst loading, and time. The catalytic system not only is capable of coupling hindered substrate but also tolerates a broad range of a series of functional groups.
- Naidu, Ajay B.,Jaseer,Sekar, Govindasamy
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supporting information; experimental part
p. 3675 - 3679
(2009/09/26)
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- An efficient intermolecular BINAM-copper(I) catalyzed Ullmann-type coupling of aryl iodides/bromides with aliphatic alcohols
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A wide range of alkyl aryl ethers are synthesized from the corresponding aryl iodides and aliphatic alcohols through Ullmann-type intermolecular coupling reactions in the presence of a catalytic amount of easily available BINAM-CuI complex. Less reactive aryl bromides have also been shown to react with aliphatic alcohols under identical reaction conditions to give good yields of the alkyl aryl ethers without increasing the reaction temperature and time.
- Naidu, Ajay B.,Sekar
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p. 3147 - 3151
(2008/09/20)
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- Synthesis of aromatic spiroacetals related to γ-rubromycin based on a 3H-spiro[1-benzofuran-2,2′-chromane] skeleton
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The synthesis of a series of aromatic 5,6-benzannelated and naphthyl-benzannelated spiroacetals related to the spiroacetal unit present in the quinonoid antibiotic γ-rubromycin is reported. The key steps include the use of Sonogashira coupling to construct an aryl acetylene that is coupled to an aryl aldehyde forming a propargyl alcohol intermediate. Hydrogenation of the resultant alkynol followed by oxidation produces a masked dihydroxyketone that upon treatment with silica-supported sodium hydrogen sulfate undergoes concomitant deprotection and cyclisation to afford the desired fused aromatic spiroacetal.
- Tsang, Kit Yee,Brimble, Margaret A.
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p. 6015 - 6034
(2008/02/02)
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- Microwave-accelerated Claisen rearrangement in bicyclic imidazolium [b-3C-im][NTf2] ionic liquid
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With microwaves, a chemically stable ionic liquid [b-3C-im][NTf2] recently developed in our laboratory was used as solvent and successfully applied to accelerate Claisen rearrangement reactions at high temperatures. In the presence of Lewis acid MgCl2, these thermal rearrangements could be achieved in similar reaction times but at lower temperature. For the microwaved reactions studied in this work, without scarifying isolated yields, the reaction times were significantly reduced from hours (by conventional heating) to ≤3 min. Our result also demonstrated that [b-3C-im][NTf2] ionic liquid was a useful solvent substitute and could be recycled multiple times for the studied rearrangement reaction at elevated temperatures.
- Lin, Yung-Lun,Cheng, Jen-Yen,Chu, Yen-Ho
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p. 10949 - 10957
(2008/02/13)
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- A facile synthesis of fused aromatic spiroacetals based on the 3,4,3′,4′-tetrahydro-2,2′-spirobis(2H-1-benzopyran) skeleton
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The facile synthesis of a series of aromatic 6,6-spiroacetals based on the parent 3,4,3′,4′-tetrahydro-2,2′-spirobis(2H-1-benzopyran) heterocyclic system is reported. Key steps included the use of a Sonogashira coupling for the synthesis of an aryl acetylene that was coupled to an aryl aldehyde to form a propargyl alcohol intermediate. Hydrogenation of the alkynol followed by oxidation produced a masked dihydroxy ketone that upon treatment with trimethylsilyl bromide underwent deprotection and cyclisation to the fused aromatic spiroacetal.
- Brimble, Margaret A.,Flowers, Christopher L.,Trzoss, Michael,Tsang, Kit Y.
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p. 5883 - 5896
(2007/10/03)
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- Asymmetric synthesis of aryloxypropanolamines via OsO4-catalyzed asymmetric dihydroxylation
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A simple and effective procedure for the enantioselective synthesis of several β-adrenergic blocking agents incorporating the first asymmetric synthesis of celiprolol, is described. The key steps are (i) sharpless asymmetric dihydroxylation of aryl allyl ethers to introduce chirality into the molecules and (ii) conversion of cyclic sulfates into the corresponding epoxides using a three-step procedure.
- Sayyed, Iliyas A.,Thakur, Vinay V.,Nikalje, Milind D.,Dewkar, Gajanan K.,Kotkar,Sudalai
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p. 2831 - 2838
(2007/10/03)
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- Synthesis of coumarins by ring-closing metathesis using Grubbs' catalyst
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A novel generally applicable synthesis of coumarins from phenolic substrates utilizing ring-closing metathesis is described. This sequence involves O-allylation of phenols followed by ortho-Claisen rearrangement, subsequent based-induced isomerization affording 2-(1-propenyl)phenols, acylation with acryloyl chloride, and finally ring-closing metathesis (RCM) with Grubbs' second generation catalyst.
- Nguyen Van, Tuyen,Debenedetti, Silvia,De Kimpe, Norbert
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p. 4199 - 4201
(2007/10/03)
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- Thermodynamic, spectroscopic, and density functional theory studies of allyl aryl and prop-1-enyl aryl ethers. Part 1. Thermodynamic data of isomerization
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A chemical equilibration study of the relative thermodynamic stabilities of seventy isomeric allyl aryl ethers (a) and (Z)-prop-1-enyl aryl ethers (b) in DMSO solution has been carried out. From the variation of the equilibrium constant with temperature the Gibbs energies, enthalpies, and entropies of isomerization at 298.15 K have been evaluated. Because of their low enthalpies, the (Z)-prop-1-enyl aryl ethers are strongly favored at equilibrium, the Gibbs energies of the a→b isomerization ranging from -12 to -23 kJ mol-1. The entropy contribution is negligible in most reactions, but occasionally small positive values less than +10 J K-1 mol-1 of the entropy of isomerization are found. The equilibration studies were also extended to involve two pairs of related isomeric ethers with a Me substituent on C(2) of the olefinic bond. The Me substituent was found to increase the relative thermodynamic stability of the allylic ethers by ca. 3.4 kJ mol-1.
- Taskinen, Esko
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p. 1824 - 1834
(2007/10/03)
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- Synthesis of the bisbenzannelated spiroketal core of the γ-rubromycins. The use of a novel Nef-type reaction mediated by Pearlman's catalyst
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The synthesis of the bisbenzannelated spiroketal core 6 of γ-rubromycin 1 from the substituted nitrostyrene 20 was achieved by using a novel Nef-type reaction mediated by Pearlman's catalyst. The precursor 28 was synthesised from readily prepared starting materials using Henry condensation chemistry. The product 6 was found to exist in two conformations in solution as shown by NMR spectroscopy.
- Capecchi, Tanya,De Koning, Charles B.,Michael, Joseph P.
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p. 2681 - 2688
(2007/10/03)
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- Facile synthesis of 5,6-dimethoxy-1-tetralone
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A facile synthesis of 5,6-dimethoxy-1-tetralone, a key intermediate in the synthesis of an antidepressant compound, ABT-200, was developed from the inexpensive starting material guaiacol.
- Lahiri, Saswata,Ramarao,Rao, B. Venkateswara,Rao, A.V. Rama,Chorghade, Mukund S.
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- Nitroalkenes as precursors to the aromatic spiroketal skeleton of γ- rubromycin. A Nef-type reaction mediated by Pearlman's catalyst
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The first synthesis of the benzannelated spiroketal core of γ- rubromycin using Henry condensations and a novel Nef-type reaction induced by Pearlman's catalyst is described.
- Capecchi, Tanya,De Koning, Charles B.,Michael, Joseph P.
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p. 5429 - 5432
(2007/10/03)
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- Asymmetric dihydroxylation of aryl allyl ethers
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Asymmetric dihydroxylation of substituted aryl allyl ethers is described. Para-substituents are shown to favor high enantioselectivity (89-95%ee), while ortho-groups have a deleterious effect (28-63%ee). Four medicinal agents were prepared: guaifenesin (expectorant), mephenesin (muscle relaxant), chlorphenesin (antifungal) and propanolol (β-blocker).
- Wang,Zhang,Sharpless
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p. 2267 - 2270
(2007/10/02)
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- 1,2-benzisoxazole compounds
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Compounds of formula I STR1 in which m represents an integer from 0 to 5, n represents an integer from 1 to 2, p is equal to 0, 1 or 2, X, Y and Z, which may be identical or different, each represent a hydrogen atom, a halogen atom, a linear or branched alkyl radical, a trifluoromethyl radical, an alkoxy radical, an alkylthio radical or a hydroxyl radical, and R represents a 2-benzofuranyl or 2,3-dihydro-2-benzofuranyl radical (it being possible for each to be substituted on the benzene ring), a 2,3,6,7-tetrahydrobenzo[1,2-b:4,5-b']difuran-2-yl radical, a 4-oxo-4H-chromen-2-yl radical (optionally substituted on the benzene ring), a benzocyclobutenyl radical of formula A or an indanyl radical of formula B: STR2 (in which: R1 and R2, which may be identical or different, each represent a hydrogen atom, a halogen atom, a trifluoromethyl radical, an alkyl radical, an alkoxy radical, a hydroxyl radical, a hydroxyalkyl radical or an alkylthio radical, or together form a methylenedioxy radical or an ethylenedioxy radical, and R3 represents a hydrogen atom or a linear or branched alkyl radical having 1 to 6 carbon atoms), or a radical of formula C: STR3 (in which R4, R5 and R6, which may be identical or different, each represent a hydrogen atom, a halogen atom, a trifluoromethyl radical, a hydroxyl radical, an alkyl radical, an alkoxy radical or an alkylthio radical, their optical isomers and their addition salts with a pharmaceutically acceptable organic or inorganic acid.
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- STRUCTURE-ACTIVITY RELATIONSHIPS OF PHENYLPROPANOIDS AS GROWTH INHIBITORS OF THE GREEN ALGA SELENASTRUM CAPRICORNUTUM
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Twenty-seven commercial or synthetic phenylpropanoids have been tested in broth against the unicellular alga Selenastrum capricornutum.The antialgal activity seems to be linked to the number as well as to the position of the methoxyl group in the molecule.A slight effect of the side chain substitution was also observed. Key Word Index - Selenastrum capricornutum; allelochemicals; phenylpropanoids.
- Greca, Marina Della,Monaco, Pietro,Pollio, Antonino,Previtera, Lucio
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p. 4119 - 4124
(2007/10/02)
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- Synthesis of methyl 2,3-dihydro-2-benzofurancarboxylates from o-allylphenols via 2-(phenylthiomethyl)-2,3-dihydrobenzofurans
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A method for synthesizing methyl 2,3-dihydro-2-benzofurancarboxylates rom o-allylphenols is described.The reaction of 6allyl-2,3-dichlorophenol (3) with benzenesulfenyl chloride (PhSCl) in acetonitrile gave a mixture of PhSCl -adducts, which was heated in aqueous acetonitrile then with sodium bicarbonate to obtain 6,7-dichloro-2-(phenylmethyl)-2,3-dihydrobenzofuran (6). α-Dichlorination of the phenylthiomethyl group of 6 and subsequent methanolysis gave the methyl ester 5 in high yield.The generality of this synthetic method was examined by the conversion of o-allylphenols 11 having various substituents on the benzene ring into the corresponding methyl ester 23.Cyclization of 11 to sulfides 12 could be achived similerly to the case of 3.However, in the subsequent conversions of 12 to 23, selective α-dichlorination followed by methanolysis could be achived only with 12 substituted with an electron-withdrawing group such as a chloro or nitro group.Keywords - oallylphenils; methyl 2,3-dihydro-2-benzofurancarboxylate; 2-(phenylthiomethyl)-2,3-dihydrobenzofuran; benzenesulfenyl chloride; α-chlorination; methanolysis.
- Yodo, Mitsuaki,Harada, Hiroshi
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p. 2361 - 2368
(2007/10/02)
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