- Electrochemical oxidation-induced benzyl C–H carbonylation for the synthesis of aromatic α-diketones
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Electrochemical oxidation-induced direct carbonylation of benzyl C–H bond for the synthesis of aromatic α-diketones is described. In this process, tetrabutylammonium iodide (nBu4NI) not only acts as an electrolyte, but its iodine anion is oxidized to an iodine radical at the anode, acting as a hydrogen atom transfer agent. The iodine radical extracts the benzyl hydrogen atom and causes the carbonylation of the benzyl position, where O2 in the air is used as an oxygen source.
- Tan, Yu-Fang,Chen, Yuan,Li, Rui-Xue,Guan, Zhi,He, Yan-Hong
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supporting information
(2021/12/21)
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- Combined Photoredox and Carbene Catalysis for the Synthesis of Ketones from Carboxylic Acids
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As a key element in the construction of complex organic scaffolds, the formation of C?C bonds remains a challenge in the field of synthetic organic chemistry. Recent advancements in single-electron chemistry have enabled new methods for the formation of various C?C bonds. Disclosed herein is the development of a novel single-electron reduction of acyl azoliums for the formation of ketones from carboxylic acids. Facile construction of the acyl azolium in situ followed by a radical–radical coupling was made possible merging N-heterocyclic carbene (NHC) and photoredox catalysis. The utility of this protocol in synthesis was showcased in the late-stage functionalization of a variety of pharmaceutical compounds. Preliminary investigations using chiral NHCs demonstrate that enantioselectivity can be achieved, showcasing the advantages of this protocol over alternative methodologies.
- Betori, Rick C.,Davies, Anna V.,Fitzpatrick, Keegan P.,Scheidt, Karl A.
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supporting information
p. 9143 - 9148
(2020/03/30)
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- Aqueous α-Arylation of Mono- and Diarylethanone Enolates at Low Catalyst Loading
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Acetophenone and deoxybenzoin derivatives are selectively α-arylated using a combination of very small amounts of palladium acetate and diphenylphosphine oxide as catalyst system and water as the only solvent. Target di- and triarylethanones are isolated virtually free of metal residues, and the reaction is amenable to gram-scale. A mechanistic proposal based on TEM images, poisoning experiments, kinetic plot and ESI-MS spectrometry is also provided. (Figure presented.).
- Astarloa, Iratxe,SanMartin, Raul,Herrero, María Teresa,Domínguez, Esther
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supporting information
p. 1711 - 1718
(2018/03/21)
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- NOVEL DIHYDROPYRIDIN-2(1H)-ONE COMPOUNDS AS S-NITROSOGLUTATHIONE REDUCTASE INHIBITORS AND NEUROKININ-3 RECEPTOR ANTAGONISTS
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The present invention is directed to novel dihydropyridin-2(1H)-one compounds useful as S-nitrosoglutathione reductase (GSNOR) inhibitors and/or Neurokinin-3 (NK3) receptor antagonists, pharmaceutical compositions comprising such compounds, and methods of making and using the same.
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Page/Page column 48
(2012/02/02)
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- NOVEL DIHYDROPYRIMIDIN-2(1H)-ONE COMPOUNDS AS S-NITROSOGLUTATHIONE REDUCTASE INHIBITORS
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The present invention is directed to novel dihydropyrimidin-2(1H)-one compounds useful as S-nitrosoglutathione reductase (GSNOR) inhibitors, pharmaceutical compositions comprising such compounds, and methods of making and using the same.
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Page/Page column 144-145
(2011/04/24)
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- Palladium-catalyzed synthesis of aryl ketones by coupling of aryl bromides with an acyl anion equivalent
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Palladium-catalyzed couplings of aryl bromides with N-tert-butylhydrazones as acyl anion equivalents to form aryl ketones are reported. The coupling process occurs at the C-position of hydrazones to form N-tert-butyl azo compounds. Isomerization of these azo compounds to the corresponding hydrazones, followed by hydrolysis, gave the desired mixed alkyl aryl ketones. The selectivity of C- versus N-arylation was strongly influenced by the substituent on nitrogen. Arylation at carbon occurred with N-tert-butylhydrazones, whereas N-arylation occurred with N-arylhydrazones. The arylation of hydrazones containing primary and secondary alkyl groups, as well as aryl groups, gave the desired ketones in good yields after hydrolysis. Functional groups on the aromatic ring, such as alkoxy, cyano, trifluoromethyl, carboalkoxy, carbamoyl, and keto groups, were tolerated. This reaction likely occurs by C-C bond-forming reductive elimination from an intermediate containing an η1-diazaallyl ligand. Copyright
- Takemiya, Akihiro,Hartwig, John F.
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p. 14800 - 14801
(2008/02/05)
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- CHEMICAL COMPOUNDS
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Compounds of formula (I):wherein variable groups are as defined within; for use in the inhibition of 11betaHSD1 are described
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- Adenosine A3 receptor antagonists
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A pharmaceutical composition for antagonizing adenosine at adenosine A3receptors which comprises a 1,3-azole compound substituted on the 4- or 5-position, or both, by a pyridyl which may be substituted is provided and can be used as a prophylactic and therapeutic agent for asthma, allergosis, inflammation, and so on.
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- An improved and practical procedure for the synthesis of substituted phenylacetylpyridines
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A general procedure for the synthesis of substituted phenylacetylpyridines in excellent yields is described using a Horner-Emmons condensation between α-aminoalkylphosphonates of pyridinecarboxaldehydes and benzaldehydes with cesium carbonate at room temperature.
- Journet, Michel,Cai, Dongwei,Larsen, Robert D.,Reider, Paul J.
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p. 1717 - 1720
(2007/10/03)
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- Proton activating factors and keto-enol-zwitterion tautomerism of 2-, 3- And 4-phenylacetylpyridines
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Equilibrium constants for keto-enol tautomerism of 2-, 3- and 4-phenylacetylpyridines in aqueous solution at 25°C have been measured as pKTE = 3.35, 4.2 and 3.1 respectively (KTE = [enol]/[ketone], PKTE = -log KTE). Corresponding values for the N-protonated ketones are 1.64, 2.80 and 1.54. These enol contents are consistently higher than those of the isomeric phenacylpyridines, except in the case of the (unprotonated) 2-isomer where the greater enol content of the latter (pKTE = 2.0) can be attributed to more effective stabilization by hydrogen-bonding to the pyridyl nitrogen in a six- than five-membered ring. The tautomeric constants were obtained by combining rate constants for enolisation, measured by halogen trapping, with rate constants for relaxation of the enol tautomer (generated by quenching the enolate anion into acid or acidic buffers) to its more stable keto isomer. Approximate tautomeric constants for zwitterion formation (pKTZ = 4.6, 7.4 and 6.1 for 2-, 3- and 4-isomers respectively) are inferred from measurements of ionisation constants and keto-enol tautomeric constants for N-methylated ketones by taking the N-methylated enolate anions as models for the zwitterions and correcting for the substituent effect of the methyl group. The tautomerism is discussed in terms of the relationship pKT = ΔpKab + log PAF which dissects tautomeric constants into contributions from (a) a difference in pKas of non-interacting acidic and basic tautomeric sites (ΔpKab) and (b) a mutual stabilisation of these sites from conjugative, inductive or hydrogen-bonded interactions between them. This stabilisation is described by a proton activating factor (PAF) measuring the effect of protonation at one tautomeric site upon the ionisation constant at the other.
- McCann, Geraldine M.,More O'Ferrall, Rory A.,Walsh, Sinead M.
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p. 2761 - 2772
(2007/10/03)
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- Substituted (1,2-Diarylethyl)amide Acyl-CoA:Cholesterol Acyltransferase Inhibitors: Effect of Polar Groups on in Vitro and in Vivo Activity
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Substituted (1,2-diarylethyl)amides have been prepared and evaluated for their ability to inhibit microsomal acyl-CoA:cholesterol acyltransferase activity in vitro and to lower hepatic cholesteryl ester content in vivo in a cholesterol-fed hamster.Simple unsubstituted (diarylethyl)amides were potent inhibitors in vitro but showed poor activity in vivo.Introduction of polar groups at specific locations on the diarylethylamine moiety decreased in vitro activity but increased in vivo activity.Both effects were highly structure dependent, suggesting specific interactions which were mediating activity in each model.Optimization of these opposing effects led to compounds which were potent in both models.
- Clader, John W.,Berger, Joel G.,Burrier, Robert E.,Davis, Harry R.,Domalski, Martin,et al.
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p. 1600 - 1607
(2007/10/02)
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- Synthese von Pyridylphenyl-imidazothiazolen
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The synthesis of the isomeric 6(5)-phenyl-5(6)-pyridyl-2,3-dihydroimidazothiazoles are described.Only the synthesis of 5-phenyl-6-(2-pyridyl)-2,3-dihydroimidazothiazole failed.
- Klose, Walter,Schwarz, Katica
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p. 669 - 671
(2007/10/02)
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- Imidazole derivatives in the treatment of pain
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Compounds of the formula SPC1 Wherein R1 represents lower alkyl, cycloalkyl or phenyl which is optionally substituted by halogen, lower alkyl or lower alkoxy, and one of the groups R2 and R3 represents phenyl which is optionally substituted by halogen, lower alkyl, hydroxy, lower alkoxy, lower alkylthio or lower alkylsulphonyl, and the other represents a 6-membered heteroaromatic radical containing 1 or 2 ring nitrogen atoms, their N-oxides and salts, with anti-inflammatory, antinociceptive and antipyretic activity, they are active ingredients of pharmaceutical compositions and can be used for the relief and removal of pain as well as for the treatment of rheumatic, arthritic and other inflammatory complaints; an illustrative example is 2-isopropyl-4(5)-(p-methoxyphenyl)-5(4)-3-pyridyl-imidazole.
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