- Redox Condensations of o-Nitrobenzaldehydes with Amines under Mild Conditions: Total Synthesis of the Vasicinone Family
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A total synthesis of the vasicinone family of natural products from bulk chemicals was developed. Reductive condensation of o-nitrobenzaldehydes with amines utilizing iron pentacarbonyl as a reducing agent followed by subsequent oxidation leads to a great variety of polycyclic nitrogen-containing heterocycles under mild conditions. Enantiomerically pure vasicinone, rutaecarpine, isaindigotone, and luotonin were synthesized from readily available starting materials like hydroxyproline, nitrobenzaldehyde, pyrrolidine, and piperidine in two to four operational steps without chromatography. The antifungal activity of all products was tested.
- Afanasyev, Oleg I.,Podyacheva, Evgeniya,Rudenko, Alexander,Tsygankov, Alexey A.,Makarova, Maria,Chusov, Denis
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p. 9347 - 9360
(2020/08/14)
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- Exceptional Substrate Diversity in Oxygenation Reactions Catalyzed by a Bis(μ-oxo) Copper Complex
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The enzyme tyrosinase contains a reactive side-on peroxo dicopper(II) center as catalytically active species in C?H oxygenation reactions. The tyrosinase activity of the isomeric bis(μ-oxo) dicopper(III) form has been discussed controversially. The synthesis of bis(μ-oxo) dicopper(III) species [Cu2(μ-O)2(L1)2](X)2 ([O1](X)2, X=PF6?, BF4?, OTf?, ClO4?), stabilized by the new hybrid guanidine ligand 2-{2-((dimethylamino)methyl)phenyl}-1,1,3,3-tetramethylguanidine (L1), and its characterization by UV/Vis, Raman, and XAS spectroscopy, as well as cryo-UHR-ESI mass spectrometry, is described. We highlight selective oxygenation of a plethora of phenolic substrates mediated by [O1](PF6)2, which results in mono- and bicyclic quinones and provides an attractive strategy for designing new phenazines. The selectivity is predicted by using the Fukui function, which is hereby introduced into tyrosinase model chemistry. Our bioinspired catalysis harnesses molecular dioxygen for organic transformations and achieves a substrate diversity reaching far beyond the scope of the enzyme.
- Paul, Melanie,Teubner, Melissa,Grimm-Lebsanft, Benjamin,Golchert, Christiane,Meiners, Yannick,Senft, Laura,Keisers, Kristina,Liebh?user, Patricia,R?sener, Thomas,Biebl, Florian,Buchenau, S?ren,Naumova, Maria,Murzin, Vadim,Krug, Roxanne,Hoffmann, Alexander,Pietruszka, J?rg,Ivanovi?-Burmazovi?, Ivana,Rübhausen, Michael,Herres-Pawlis, Sonja
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supporting information
p. 7556 - 7562
(2020/05/29)
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- Selective butyrylcholine esterase inhibitor or pharmaceutically acceptable salt thereof, and preparation method and application thereof
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The invention discloses a selective butyrylcholine esterase inhibitor represented by a general formula (I) or a pharmaceutically acceptable salt thereof, and a preparation method and an application thereof. Butyrylcholine esterase inhibitory activity, sel
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- New phenylaniline derivatives as modulators of amyloid protein precursor metabolism
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The chloroquinoline scaffold is characteristic of anti-malarial drugs such as chloroquine (CQ) or amodiaquine (AQ). These drugs are also described for their potential effectiveness against prion disease, HCV, EBV, Ebola virus, cancer, Parkinson or Alzheimer diseases. Amyloid precursor protein (APP) metabolism is deregulated in Alzheimer's disease. Indeed, CQ modifies amyloid precursor protein (APP) metabolism by precluding the release of amyloid-beta peptides (Aβ), which accumulate in the brain of Alzheimer patients to form the so-called amyloid plaques. We showed that AQ and analogs have similar effects although having a higher cytotoxicity. Herein, two new series of compounds were synthesized by replacing 7-chloroquinolin-4-amine moiety of AQ by 2-aminomethylaniline and 2-aminomethylphenyle moieties. Their structure activity relationship was based on their ability to modulate APP metabolism, Aβ release, and their cytotoxicity similarly to CQ. Two compounds 15a, 16a showed interesting and potent effect on the redirection of APP metabolism toward a decrease of Aβ peptide release (in the same range compared to AQ), and a 3–10-fold increased stability of APP carboxy terminal fragments (CTFα and AICD) without obvious cellular toxicity at 100 μM.
- Gay, Marion,Carato, Pascal,Coevoet, Mathilde,Renault, Nicolas,Larchanché, Paul-Emmanuel,Barczyk, Amélie,Yous, Sa?d,Buée, Luc,Sergeant, Nicolas,Melnyk, Patricia
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p. 2151 - 2164
(2018/03/23)
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- Hydrogenation of (N,N-disubstituted aminomethyl)nitrobenzenes to (N,N-disubstituted aminomethyl)anilines catalyzed by palladium-nickel bimetallic nanoparticles
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Since palladium-catalysts have strong abilities for both hydrogenation of nitro-group and hydrogenolysis of benzylamine, they have a much lower chemoselectivity for the hydrogenation of (N,N-disubstituted aminomethyl)nitrobenzenes. In this article, component stable Pd-Ni bimetallic nanoparticles were prepared by simply heating RANEY-Ni and Na2PdCl4 together in water. They demonstrated novel synergistic effects when they were used as a bimetallic catalyst, by which a highly efficient and chemoselective hydrogenation of (N,N-disubstituted aminomethyl)nitrobenzenes to (N,N-disubstituted aminomethyl)anilines was achieved.
- Bao, Hailin,Wang, Dingsheng,Wang, Xinyan,Cheng, Chuanjie,Li, Yadong,Hu, Yuefei
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p. 47125 - 47130
(2015/06/16)
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- SUBSTITUTED N-ARYL-9-OXO-9H-FLUORENE-1-CARBOXAMIDES AND ANALOGS AS ACTIVATOR OF CASPASES AND INDUCERS OF APOPTOSIS
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The present invention is directed to substituted N-aryl-9-oxo-9H-fluorene-1-carboxamides and analogs thereof, represented by the general Formula I: (I) wherein R1-R8, X and Ar are defined herein. The present invention also relates to the discovery that co
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Page/Page column 41-43
(2010/10/20)
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- Synthesis of methyl carbamates from primary aliphatic amines and dimethyl carbonate in supercritical CO2: Effects of pressure and cosolvents and chemoselectivity
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(Chemical Equation Presented) At 130 °C, in the presence of CO 2 (5-200 bar), primary aliphatic amines react with dimethyl carbonate (MeOCO2Me, DMC) to yield methyl carbamates (RNHCO2Me) and N-methylation side-products (RNHMe and RNMe2). The pressure of CO2 largely influences both the reaction conversion and the selectivity toward urethanes: in general, conversion goes through a maximum (70-80%) in the midrange (40 bar) and drops at lower and higher pressures, whereas selectivity is continuously improved (from 50% up to 90%) by an increase of the pressure. This is explained by the multiple role of CO2 in (i) the acid/base equilibrium with aliphatic amines, (ii) the reactivity/solubility of RNHCO2- nucleophiles with/in DMC, and (iii) the inhibition of competitive N-methylation reaction of the substrates. Cosolvents also affect the reaction: in particular, a drop in selectivity is observed with polar protic media (i.e., MeOH), plausibly because of solvation effects (through H-bonds) of RNHCO2- moieties. The reaction shows also a good chemoselectivity: bifunctional aliphatic amines bearing either aromatic NH2 or OH substituents [XC6H4(CH2)nNH2, X = NH2, OH; n = 1 2], undergo methoxycarbonylation reactions exclusively at aliphatic amino groups and give the corresponding methyl carbamates [XC 6H4(CH2)nNHCO2Me] in 39-65% isolated yields.
- Selva, Maurizio,Tundo, Pietro,Perosa, Alvise,Dall'Acqua, Federico
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p. 2771 - 2777
(2007/10/03)
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- 2-(Tosylamino)benzyltrimethylammonium halides as precursors of 2-substituted indoles
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The reactions of 2-(tosylamino)benzyltrimethylammonium halides (1) with dimethylsulfonium 2-oxo-2-phenylethylide (6b), dimethylsulfonium 2-ethoxy-2-oxo-ethylide (6c) and dimethylsulfonium cyanomethylide (6d) are useful synthetic routes to 2-substituted indoles (8b-d). The relationship between reaction conditions and selectivity is discussed.
- Croce, Piero Dalla,Ferraccioli, Raffaella,La Rosa, Concetta
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p. 2397 - 2407
(2007/10/03)
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- POTENTIAL ANTIDEPRESSANTS. SYNTHESIS OF 6,11-DIHYDRODIBENZOTHIEPIN-11-YL (DIMETHYLAMINOMETHYL)PHENYL ETHERS, SULFIDES, AMINES AND SOME RELATED COMPOUNDS
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Reactions of 11-chloro-6,11-dihydrodibenzothiepin and its 2-bromo derivative with the isomeric (dimethylaminomethyl)phenols, (dimethylaminomethyl)thiophenols, and (dimethylaminomethyl)anilines in toluene afforded the title compounds IIIb,c, Va, VIIIa,b,c, and Xa,b,c.Reactions of 11-chloro-6,11-dihydrodibenzothiepin and its 2-chloro and 2-methyl derivatives with N,N-dimethyl-2-(4-aminophenoxy)ethylamine and N,N-dimethyl-3-(4-aminophenoxy)propylamine by heating in dimethylformamide in the presence of sodium carbonate gave the diamino ethers XI-XIV.Thecompounds showed only indications of the antidepressant agents profile and some antimicrobial effects in vitro.
- Sindelar, Karel,Valenta, Vladimir,Holubek, Jiri,Matousova, Oluse,Protiva, Miroslav
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p. 282 - 295
(2007/10/02)
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- Synthesis and Reactions of Trimethylsilylmethyl Azide
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Trimethylsilylmethyl azide, prepared quantitatively from trimethylsilylmethyl chloride and sodium azide, could be used for the amination of aryl Grignard reagents or aryl-lithium compounds.
- Nishiyama, Kozaburo,Tanaka, Nobuko
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p. 1322 - 1323
(2007/10/02)
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- A USEFUL METHOD TO INTRODUCE ORTHO AMINO GROUPS IN AROMATIC COMPOUNDS
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Aromatic lithio compounds were reacted with tosyl azide and the resulting triazenes, in situ, were reduced with Ni-Al alloy to give primary aromatic amines.
- Narasimhan, Nurani S.,Ammanamanchi, RadhaKrishna
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p. 4733 - 4734
(2007/10/02)
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