- Salt-Free Strategy for the Insertion of CO2 into C?H Bonds: Catalytic Hydroxymethylation of Alkynes
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A copper(I) catalyst enables the insertion of carbon dioxide into alkyne C?H bonds by using a suitable organic base with which hydrogenation of the resulting carboxylate salt with regeneration of the base becomes thermodynamically feasible. In the presence of catalytic copper(I) chloride/4,7-diphenyl-1,10-phenanthroline, polymer-bound triphenylphosphine, and 2,2,6,6-tetramethylpiperidine as the base, terminal alkynes undergo carboxylation at 15 bar CO2 and room temperature. After filtration, the ammonium alkynecarboxylate can be hydrogenated to the primary alcohol and water at a rhodium/molybdenum catalyst, regenerating the amine base. This demonstrates the feasibility of a salt-free overall process, in which carbon dioxide serves as a C1 building block in a C?H functionalization.
- Wendling, Timo,Risto, Eugen,Krause, Thilo,Goo?en, Lukas J.
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Read Online
- Ruthenium-catalyzed reduction of allylic alcohols using glycerol as solvent and hydrogen donor
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Glycerol, a biodegradable and virtually non-toxic chemical, can be used as a green solvent and hydrogen donor in the ruthenium-catalyzed reduction of allylic alcohols, a tandem process that involves the initial redox-isomerization of the allylic alcohol and subsequent transfer hydrogenation of the resulting carbonyl compound. Among the different ruthenium sources employed, the best results were obtained with the hydrophilic arene-Ru(II) complex [RuCl 2(η6-C6H6)(DAPTA)] (DAPTA = 3,7-diacetyl-1,3,7-triaza-5-phosphabicyclo[3.3.1]nonane), which associated with KOH generates the corresponding saturated alcohols in high yields (up to 90%) and with almost complete selectivity in short reaction times. Interestingly, these reduction processes are also operative using technical grade glycerol.
- Díaz-álvarez, Alba E.,Crochet, Pascale,Cadierno, Victorio
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Read Online
- Iridium-Catalyzed Domino Hydroformylation/Hydrogenation of Olefins to Alcohols: Synergy of Two Ligands
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A novel one-pot iridium-catalyzed domino hydroxymethylation of olefins, which relies on using two different ligands at the same time, is reported. DFT computation reveals different activities for the individual hydroformylation and hydrogenation steps in the presence of mono- and bidentate ligands. Whereas bidentate ligands have higher hydrogenation activity, monodentate ligands show higher hydroformylation activity. Accordingly, a catalyst system is introduced that uses dual ligands in the whole domino process. Control experiments show that the overall selectivity is kinetically controlled. Both computation and experiment explain the function of the two optimized ligands during the domino process.
- Huang, Weiheng,Tian, Xinxin,Jiao, Haijun,Jackstell, Ralf,Beller, Matthias
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supporting information
(2022/01/13)
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- Umpolung Strategy for Arene C?H Etherification Leading to Functionalized Chromanes Enabled by I(III) N-Ligated Hypervalent Iodine Reagents
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The direct formation of aryl C?O bonds via the intramolecular dehydrogenative coupling of a C?H bond and a pendant alcohol represents a powerful synthetic transformation. Herein, we report a method for intramolecular arene C?H etherification via an umpoled alcohol cyclization mediated by an I(III) N-HVI reagent. This approach provides access to functionalized chromane scaffolds from primary, secondary and tertiary alcohols via a cascade cyclization-iodonium salt formation, the latter providing a versatile functional handle for downstream derivatization. Computational studies support initial formation of an umpoled O-intermediate via I(III) ligand exchange, followed by competitive direct and spirocyclization/1,2-shift pathways. (Figure presented.).
- Mikhael, Myriam,Guo, Wentao,Tantillo, Dean J.,Wengryniuk, Sarah E.
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supporting information
p. 4867 - 4875
(2021/09/14)
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- Access to Trisubstituted Fluoroalkenes by Ruthenium-Catalyzed Cross-Metathesis
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Although the olefin metathesis reaction is a well-known and powerful strategy to get alkenes, this reaction remained highly challenging with fluororalkenes, especially the Cross-Metathesis (CM) process. Our thought was to find an easy accessible, convenient, reactive and post-functionalizable source of fluoroalkene, that we found as the methyl 2-fluoroacrylate. We reported herein the efficient ruthenium-catalyzed CM reaction of various terminal and internal alkenes with methyl 2-fluoroacrylate giving access, for the first time, to trisubstituted fluoroalkenes stereoselectively. Unprecedent TON for CM involving fluoroalkene, up to 175, have been obtained and the reaction proved to be tolerant and effective with a large range of olefin partners giving fair to high yields in metathesis products. (Figure presented.).
- Nouaille, Augustin,Pannecoucke, Xavier,Poisson, Thomas,Couve-Bonnaire, Samuel
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supporting information
p. 2140 - 2147
(2021/03/06)
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- Compounds for and methods of treating diseases
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The present invention provides heterocyclic compounds of formula (I) that modulate biological metals and to pharmaceutical compositions containing such compounds. The invention particularly relates to compounds that modulate iron and to compounds for the treatment of diseases, particularly neurological diseases such as Parkinson's disease (PD), Alzheimer's disease (AD), Alzheimer-type dementia, Huntington's disease (HD), amyotrophic lateral sclerosis (ALS), frontotemporal dementia (FTD) and multiple system atrophy (MSA).
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- Probing the Existence of a Metastable Binding Site at the β2-Adrenergic Receptor with Homobivalent Bitopic Ligands
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Herein, we report the development of bitopic ligands aimed at targeting the orthosteric binding site (OBS) and a metastable binding site (MBS) within the same receptor unit. Previous molecular dynamics studies on ligand binding to the β2-adrenergic receptor (β2AR) suggested that ligands pause at transient, less-conserved MBSs. We envisioned that MBSs can be regarded as allosteric binding sites and targeted by homobivalent bitopic ligands linking two identical pharmacophores. Such ligands were designed based on docking of the antagonist (S)-alprenolol into the OBS and an MBS and synthesized. Pharmacological characterization revealed ligands with similar potency and affinity, slightly increased β2/β1AR-selectivity, and/or substantially slower β2AR off-rates compared to (S)-alprenolol. Truncated bitopic ligands suggested the major contribution of the metastable pharmacophore to be a hydrophobic interaction with the β2AR, while the linkers alone decreased the potency of the orthosteric fragment. Altogether, the study underlines the potential of targeting MBSs for improving the pharmacological profiles of ligands.
- Gaiser, Birgit I.,Danielsen, Mia,Marcher-R?rsted, Emil,R?pke J?rgensen, Kira,Wróbel, Tomasz M.,Frykman, Mikael,Johansson, Henrik,Br?uner-Osborne, Hans,Gloriam, David E.,Mathiesen, Jesper Mosolff,Sejer Pedersen, Daniel
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p. 7806 - 7839
(2019/09/07)
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- Synthesis, in vitro and in silico evaluation of diaryl heptanones as potential 5LOX enzyme inhibitors
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A new series of diaryl heptanones (12a-q) were synthesized and their structures were confirmed by its 1H, 13C NMR and Mass spectral data. These analogs were evaluated for their anti-oxidant activity and potential to inhibit 5-lipoxygenase. Compounds 12k and 12o showed potent in vitro 5-lipoxygenase enzyme inhibitory activity with IC50 values of 22.2, 21.5 μM, which are comparable to curcumin (24.4 μM). Further they also have shown significant antioxidant activity. Molecular docking studies clearly showed correlation between binding energy and potency of these compounds.
- Meka, Bharani,Ravada, Suryachandra Rao,Muthyala, Murali Krishna Kumar,Kurre, Purna Nagasree,Golakoti, Trimurtulu
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p. 408 - 421
(2018/07/13)
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- Nucleophilic Amination of Methoxy Arenes Promoted by a Sodium Hydride/Iodide Composite
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A method for the nucleophilic amination of methoxy arenes was established by using sodium hydride (NaH) in the presence of lithium iodide (LiI). This method offers an efficient route to benzannulated nitrogen heterocycles. Mechanistic studies showed that the reaction proceeds through an unusual concerted nucleophilic aromatic substitution.
- Kaga, Atsushi,Hayashi, Hirohito,Hakamata, Hiroyuki,Oi, Miku,Uchiyama, Masanobu,Takita, Ryo,Chiba, Shunsuke
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supporting information
p. 11807 - 11811
(2017/09/20)
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- Stereoselective organocatalytic oxidation of alcohols to enals: A homologation method to prepare polyenes
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A novel method for organocatalytic oxidation through oxidative enamine catalysis was developed with excellent compatibility for the direct syntheses of enals from simple saturated alcohols. By using this amine-catalyzed IBX-oxidation, a wide range of aromatic and aliphatic substituted enals were successfully generated in high yields and exclusively stereoselective E-geometry. Moreover, varying the solvents and/or the loading amounts of IBX allowed for the selective oxidation of alcohols and aldehydes. Importantly, the homologous application of this method provided a selective and efficient way of preparing various highly sensitive conjugated polyene frameworks, which are enriched in natural products.
- Chen, Xiaobei,Zhang, Yinan,Wan, Huixin,Wang, Wei,Zhang, Shilei
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p. 3532 - 3535
(2016/03/04)
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- Synthesis of 2-tetralone derivatives by Bi(OTf)3-catalyzed intramolecular hydroarylation/isomerization of propargyl alcohols
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Compared to 1-tetralones, 2-tetralones are expensive, less stable, and difficult to synthesize. A concise Bi-catalyzed method was developed for the synthesis of 2-tetralones from 5-phenylpent-1-yn-3-ol derivatives. Diverse 2-tetralones were obtained in moderate to good yields under mild conditions.
- Yun, Jihee,Park, Jungmin,Kim, Jaehyun,Lee, Kooyeon
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p. 1045 - 1048
(2015/02/19)
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- RE12 derivatives displaying Vaccinia H1-related phosphatase (VHR) inhibition in the presence of detergent and their anti-proliferative activity against HeLa cells
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New derivatives of Vaccinia H1-related phosphatase (VHR) inhibitor RE12 (5) were designed by replacing the long straight alkyl chain with other hydrophobic functionalities containing two aromatic rings, with the aim of obtaining potent, cell-active inhibitors. We established a direct coupling reaction between tetronic acid derivative and thioimidate to prepare the RE derivatives 6a-6i efficiently. These compounds all showed VHR-inhibitory activity in the presence of 0.001% NP-40, whereas RE12 (5) was inactive under this condition, even at 100 μM. Further structure-activity studies focused on terminal substitution afforded trifluoromethyl derivative 6k (RE176) and nitro derivative 6l (RE177). The IC50 value of 6l in the presence of NP-40 was almost equivalent to that of RE12 (5) in its absence. Compound 6k (RE176) potently inhibited proliferation of HeLa cells.
- Thuaud, Frederic,Kojima, Shuntaro,Hirai, Go,Oonuma, Kana,Tsuchiya, Ayako,Uchida, Takako,Tsuchimoto, Teruhisa,Sodeoka, Mikiko
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p. 2771 - 2782
(2014/05/06)
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- Discovery of synthetic methoxy-substituted 4-phenylbutyric acid derivatives as chemical chaperones
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In this study, we evaluated the chemical chaperone activity of synthetic 4-phenylbutyric acid (4-PBA) derivatives. These derivatives have a methoxy group at the benzene ring and/or longer or shorter fatty acid portions. Several 4-PBA derivatives demonstrated higher antiaggregation activity than 4-PBA. Moreover, 4-(4-methoxyphenyl)butanoic acid (7b) showed protective effects against endoplasmic reticulum stress-induced neuronal cell death.
- Mimori, Seisuke,Okuma, Yasunobu,Kaneko, Masayuki,Kawada, Koichi,Nomura, Yasuyuki,Murakami, Yasuoki,Hamana, Hiroshi
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supporting information
p. 1051 - 1052
(2013/09/24)
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- New serotonin 5-HT1A receptor agonists endowed with antinociceptive activity in vivo
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We report the synthesis of new compounds 4-35 based on two different openings (A and B) of the chromane ring present in the previously identified 5-HT1A receptor (5-HT1AR) ligand 3. The synthesized compounds were assessed for binding affinity, selectivity, and functional activity at the 5-HT1AR. Selected candidates resulting from B opening were also evaluated for their potential antinociceptive effect in vivo and pharmacokinetic properties in vitro. Analogue 19 [2-(4-{[2-(2-ethoxyphenoxy) ethyl]amino}butyl)tetrahydro-1H-pyrrolo[1,2-c]imidazole-1,3(2H)-dione] has been characterized as a high-affinity and potent 5-HT1AR agonist (K i = 2.3 nM; EC50 = 19 nM). Pharmacokinetic studies indicated that compound 19 displays a good metabolic stability in human liver microsomes (t1/2 ~ 3 h and CLint = 3.5 mL/min/kg, at 5 μM), and a low level of protein binding (25%, at 5 μM). Interestingly, 19 (3 mg/kg, ip, and 30 mg/kg, po) caused significant attenuation of formalin-induced behavior in early and late phases of the mouse intradermal formalin test of pain, and this in vivo effect was reversed by the selective 5-HT1AR antagonist WAY-100635. Thus, the new 5-HT1AR agonist identified in this work, 19, exhibits oral analgesic activity, and the results herein represent a step toward identifying new therapeutics for the control of pain.
- Valhondo, Margarita,Marco, Isabel,Martín-Fontecha, Mar,Vázquez-Villa, Henar,Ramos, José A.,Berkels, Reinhard,Lauterbach, Thomas,Benhamú, Bellinda,López-Rodríguez, María L.
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supporting information
p. 7851 - 7861
(2013/11/06)
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- Tandem phenolic oxidative amidation-intramolecular diels-alder reaction: An approach to the himandrine core
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An oxidative cyclization of dienic sulfonamides mediated by iodobenzene diacetate in TFA, followed by a tandem intramolecular Diels-Alder reaction, achieves desymmetrization of a "locally symmetrical" dienone with good levels of diastereoselectivity and leads to valuable synthetic intermediates for the himandrine alkaloids.
- Liang, Huan,Ciufolini, Marco A.
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supporting information; experimental part
p. 1760 - 1763
(2010/10/21)
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- Oxidative spirocyclization of phenolic sulfonamides: Scope and applications
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A full account of the oxidative dearomatization of para- and ortho-phenolic sulfonamides is provided together with an overview of the chemistry of the products and their elaboration to building blocks for spirocyclic alkaloids. A concise total synthesis of putative lepadiformine complements the discussion. Making building blocks: The oxidative dearomatization of para- and ortho-phenolic sulfonamides provides building blocks for spirocyclic alkaloids (see scheme). The chemistry of the products of this reaction and a concise total synthesis of putative lepadiformine is given.
- Liang, Huan,Ciufolini, Marco A.
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supporting information; experimental part
p. 13262 - 13270
(2011/03/17)
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- Ruthenium-catalyzed redox isomerization/transfer hydrogenation in organic and aqueous media: A one-pot tandem process for the reduction of allylic alcohols
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The hexamethylbenzene-ruthenium(ii) dimer [{RuCl(μ-Cl) (η6-C6Me6)}2] 1 and the mononuclear bis(allyl)-ruthenium(iv) complex [RuCl2(η 3:η2:η3-C12H 18)]2, associated with base and a hydrogen donor, were found to be active catalysts for the selective reduction of the CC bond of allylic alcohols both in organic and aqueous media. The process, which proceeds in a one-pot manner, involves a sequence of two independent reactions: (i) the initial redox-isomerization of the allylic alcohol, and (ii) subsequent transfer hydrogenation of the resulting carbonyl compound. The highly efficient transformation reported herein represents, not only an illustrative example of auto-tandem catalysis, but also an appealing alternative to the classical transition-metal catalyzed CC hydrogenations of allylic alcohols. The process has been successfully applied to aromatic as well as aliphatic substrates affording the corresponding saturated alcohols in 45-100% yields after 1.5-24 h. The best performances were reached using (i) 1-5 mol% of 1 or 2, 2-10 mol% of Cs2CO3, and propan-2-ol or (ii) 1-5 mol% of 1 or 2, 10-15 equivalents of NaO2CH, and water. The catalytic efficiency is strongly related to the structure of the allylic alcohol employed. Thus, in propan-2-ol, the reaction rate essentially depends on the steric requirement around the CC bond, therefore decreasing with the increasing number of substituents. On other hand, in water the transformation is favoured for primary allylic alcohols vs. secondary ones.
- Cadierno, Victorio,Crochet, Pascale,Francos, Javier,Garcia-Garrido, Sergio E.,Gimeno, Jose,Nebra, Noel
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scheme or table
p. 1992 - 2000
(2010/06/19)
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- SPHINGOSINE-1 -PHOSPHATE RECEPTOR AGONIST AND ANTAGONIST COMPOUNDS
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The present invention is directed to novel, potent, and selective agents, which are agonists or antagonists of the one or more of the individual receptors of the S1P receptor family. The compounds of the invention are useful as therapeutics for treating medical conditions associated with agonism or antagonism of the individual receptors of the S1P receptor family.
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Page/Page column 127-128
(2008/12/07)
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- Intramolecular C-N bond formation reactions catalyzed by ruthenium porphyrins: Amidation of sulfamate esters and aziridination of unsaturated sulfonamides
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Ruthenium porphyrins [Ru(F20-TPP)(CO)] (F20-TPP = 5,10,15,20-tetrakis(pentafluorophenyl)porphyrinato dianion) and [Ru(Por*)(CO)] (Por* = 5,10,15,20-tetrakis[(1S,4R,5R,8S)-1,2,3,4,5,6,7,8-octahydro-1,4:5, 8-dimethanoanthracen-9-yl]porphyrinato dianion) catalyzed intramolecular amidation of sulfamate esters p-X-C6H4(CH 2)2OSO2NH2 (X = Cl, Me, MeO), XC6H4(CH2)3OSO2NH 2 (X = p-F, p-MeO, m-MeO), and Ar(CH2)2OSO 2NH2 (Ar = naphthalen-1-yl, naphthalen-2-yl) with PhI(OAc)2 to afford the corresponding cyclic sulfamidates in up to 89% yield with up to 100% substrate conversion; up to 88% ee was attained in the asymmetric intramolecular amidation catalyzed by [Ru(Por*)(CO)]. Reaction of [Ru(F20-TPP)(CO)] with PhI=NSO2OCH 2CCl3 (prepared by treating the sulfamate ester Cl 3CCH2OSO2NH2 with PhI(OAc) 2) afforded a bis(imido)ruthenium(VI) porphyrin, [Ru VI(F20-TPP)(NSO2OCH2CCl 3)2], in 60% yield. A mechanism involving reactive imido ruthenium porphyrin intermediate was proposed for the ruthenium porphyrin-catalyzed intramolecular amidation of sulfamate esters. Complex [Ru(F20-TPP)(CO)] is an active catalyst for intramolecular aziridination of unsaturated sulfonamides with PhI(OAc)2, producing corresponding bicyclic aziridines in up to 87% yield with up to 100% substrate conversion and high turnover (up to 2014).
- Liang, Jiang-Lin,Yuan, Shi-Xue,Huang, Jie-Sheng,Che, Chi-Ming
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p. 3610 - 3619
(2007/10/03)
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- Inhibitors of microsomal triglyceride transfer protein and method
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Compounds are provided which inhibit microsomal triglyceride transfer protein and thus are useful for lowering serum lipids and treating atherosclerosis and related diseases. The compounds have the structure STR1 wherein R1 to R7, Q, X and Y are as defined herein.
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- Synthesis and biological activity of cinnamaldehydes as angiogenesis inhibitors
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A series of 2-hydroxycinnamaldehyde derivatives was synthesized for examing a structure-activity relationship for inhibition of angiogenesis. The anti-angiogenic effects of 2'-substituted cinnamaldehydes and related analogs were determined in a chick embryo chorioallantoic membrane assay system.
- Kwon, Byoung-Mog,Lee, Seung-Ho,Cho, Young-Kwon,Bok, Song-Hae,So, Seung-Ho,Youn, Mi-Ran,Chang, Soo-Ik
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p. 2473 - 2476
(2007/10/03)
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- ALPHA-OMEGA-DIARYLALKANE COMPOUNDS SEROTONIN-2 RECEPTOR AGONISTS
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Compounds of formula (I): STR1 [wherein: R 1 is aryl; R 2 is hydrogen, alkyl, alkoxy, halogen or cyano; R 3 is a group of formula--B--NR 4 R 5, where R 4 and R 5 are independently hydrogen, alkyl or substituted alkyl or R 4 and R 5, together with the nitr
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- Radical isomerization via intramolecular ipso substitution of aryl ethers: Aryl translocation from oxygen to carbon
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Bromopropyl aryl ethers an converted to 3-arylpropanols under standard radical generating conditions in the presence of tributylstannane and AIBN. This rearrangement involves intramolecular ipso attack of the alkyl radicals which generates spiro cyclohexadienyl radical intermediates.
- Lee, Eun,Lee, Chulbom,Tae, Jin Sung,Whang, Ho Sung,Li, Kap Sok
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p. 2343 - 2346
(2007/10/02)
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- SELECTIVE DEMETHYLATION OF ALIPHATIC METHYL ETHER IN THE PRESENCE OF AROMATIC METHYL ETHER WITH THE ALUMINUM CHLORIDE-SODIUM IODIDE-ACETONITRILE SYSTEM
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A combination system of aluminum chloride-sodium iodide-acetonitrile effects selective demethylation of aliphatic methyl ethers in the presence of aromatic methyl ether.KEYWORDS - demethylation; methyl ether; aluminum chloride; sodium iodide; hard acid; soft nucleophile
- Node, Manabu,Ohta, Keiichiro,Kajimoto, Tetsuya,Nishide, Kiyoharu,Fujita, Eiichi,Fuji, Kaoru
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p. 4178 - 4180
(2007/10/02)
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- Methylase Models: Studies on General-Base vs. Nucleophilic Catalysis in the Intramolecular Alkylation of Phenols
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The ortho substituted phenols, 1 and 3, have been synthesized as models for the O-methylation of catecholamines, as catalyzed by catechol O-methyltransferase.The decomposition of 1 and 3 was studied at 40 deg C over a wide range of pH in both oxyanion and
- Knipe, Jay O.,Vasquez, Peter J.,Coward, James K.
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p. 3202 - 3209
(2007/10/02)
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