- A Mild Method for Electrochemical Reduction of Heterocyclic N-Oxides
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Deoxygenation of heteroaromatic N-oxides is commonly accomplished using chemical or enzymatic methods. In this work, we report on an expedient protocol for electrochemical reduction of pyridine N-oxide derivatives under mild conditions. A diverse range of mono- and bis N-oxides were converted into the corresponding nitrogen bases in good yields. Importantly, the method is highly selective towards N-oxides and tolerates challenging halo and nitro substituents in the heteroaromatic ring.
- Fukazawa, Yasuaki,Rubtsov, Aleksandr E.,Malkov, Andrei V.
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supporting information
p. 3317 - 3319
(2020/05/25)
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- Novel 8-nitroquinolin-2(1H)-ones as NTR-bioactivated antikinetoplastid molecules: Synthesis, electrochemical and SAR study
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To study the antiparasitic 8-nitroquinolin-2(1H)-one pharmacophore, a series of 31 derivatives was synthesized in 1–5 steps and evaluated in vitro against both Leishmania infantum and Trypanosoma brucei brucei. In parallel, the reduction potential of all molecules was measured by cyclic voltammetry. Structure-activity relationships first indicated that antileishmanial activity depends on an intramolecular hydrogen bond (described by X-ray diffraction) between the lactam function and the nitro group, which is responsible for an important shift of the redox potential (+0.3 V in comparison with 8-nitroquinoline). With the assistance of computational chemistry, a set of derivatives presenting a large range of redox potentials (from ?1.1 to ?0.45 V) was designed and provided a list of suitable molecules to be synthesized and tested. This approach highlighted that, in this series, only substrates with a redox potential above ?0.6 V display activity toward L. infantum. Nevertheless, such relation between redox potentials and in vitro antiparasitic activities was not observed in T. b. brucei. Compound 22 is a new hit compound in the series, displaying both antileishmanial and antitrypanosomal activity along with a low cytotoxicity on the human HepG2 cell line. Compound 22 is selectively bioactivated by the type 1 nitroreductases (NTR1) of L. donovani and T. brucei brucei. Moreover, despite being mutagenic in the Ames test, as most of nitroaromatic derivatives, compound 22 was not genotoxic in the comet assay. Preliminary in vitro pharmacokinetic parameters were finally determined and pointed out a good in vitro microsomal stability (half-life > 40 min) and a 92% binding to human albumin.
- Pedron, Julien,Boudot, Clotilde,Hutter, Sébastien,Bourgeade-Delmas, Sandra,Stigliani, Jean-Luc,Sournia-Saquet, Alix,Moreau, Alain,Boutet-Robinet, Elisa,Paloque, Lucie,Mothes, Emmanuelle,Laget, Michèle,Vendier, Laure,Pratviel, Geneviève,Wyllie, Susan,Fairlamb, Alan,Azas, Nadine,Courtioux, Bertrand,Valentin, Alexis,Verhaeghe, Pierre
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p. 135 - 152
(2018/06/08)
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- B(C6F5)3-Catalyzed Deoxygenation of Sulfoxides and Amine N-Oxides with Hydrosilanes
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An efficient strategy for the deoxygenation of sulfoxides and amine N-oxides by using B(C6F5)3 and hydrosilanes was developed. This method provided the corresponding aromatic and aliphatic products in good to high yields and showed good functional-group tolerance under mild conditions.
- Ding, Fangwei,Jiang, Yanqiu,Gan, Shaoyan,Bao, Robert Li-Yuan,Lin, Kaifeng,Shi, Lei
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p. 3427 - 3430
(2017/07/04)
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- Copper-catalyzed oxygen atom transfer of N-oxides leading to a facile deoxygenation procedure applicable to both heterocyclic and amine N-oxides
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Deoxygenation of various types of N-oxides including both heterocyclic and alkyl(aryl)amine derivatives has successfully been developed by the copper-catalyzed oxygen atom transfer using diazo compounds as the oxygen acceptor. The reaction proceeds smoothly over a broad range of substrates with excellent functional group tolerance under mild conditions. This journal is
- Jeong, Jisu,Lee, Donggun,Chang, Sukbok
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supporting information
p. 7035 - 7038
(2015/04/22)
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- One-pot synthesis of N-aryl propargylamine from aromatic boronic acid, aqueous ammonia, and propargyl bromide under microwave-assisted conditions
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A facile, one-pot synthesis of N-aryl propargylamine from aromatic boronic acid, aqueous ammonia, and propargyl bromide has been achieved under microwave-assisted conditions. The reactions can be smoothly completed within a total 10 min through a two-step procedure, including copper-catalyzed coupling of aromatic boronic acids with aqueous ammonia and following propargylation by propargyl bromide.
- Jiang, Yu-Bo,Zhang, Wen-Sheng,Cheng, Hui-Ling,Liu, Yu-Qi,Yang, Rui
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p. 779 - 782
(2014/06/09)
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- Discovery of a new antileishmanial hit in 8-nitroquinoline series
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A series of nitrated 2-substituted-quinolines was synthesized and evaluated in vitro toward Leishmania donovani promastigotes. In parallel, the in vitro cytotoxicity of these molecules was assessed on the murine J774 and human HepG2 cell lines. Thus, a very promising antileishmanial hit molecule was identified (compound 21), displaying an IC50 value of 6.6 μM and CC 50 values ≥ 100 μM, conferring quite good selectivity index to this molecule, in comparison with 3 drug-compounds of reference (amphotericin B, miltefosine and pentamidine). Compound 21 also appears as an efficient in vitro antileishmanial molecule against both Leishmania infantum promastigotes and the intracellular L. donovani amastigotes (respective IC50 = 7.6 and 6.5 μM). Moreover, hit quinoline 21 does not show neither significant antiplasmodial nor antitoxoplasmic in vitro activity and though, presents a selective antileishmanial activity. Finally, a structure-activity relationships study enabled to define precisely the antileishmanial pharmacophore based on this nitroquinoline scaffold: 2-hydroxy-8-nitroquinoline.
- Paloque, Lucie,Verhaeghe, Pierre,Casanova, Magali,Castera-Ducros, Caroline,Dumetre, Aurelien,Mbatchi, Litaty,Hutter, Sebastien,Kraiem-M'Rabet, Manel,Laget, Michele,Remusat, Vincent,Rault, Sylvain,Rathelot, Pascal,Azas, Nadine,Vanelle, Patrice
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experimental part
p. 75 - 86
(2012/09/08)
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- Chemokine receptor binding heterocyclic compounds
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This invention relates to a novel class of heterocyclic compounds that bind chemokine receptors, inhibiting the binding of their natural ligands thereby. These compounds result in protective effects against infection by HIV through binding to chemokine receptors, including CXCR4 and CCR5, thus inhibiting the subsequent binding by these chemokines. The present invention provides a compound of Formula I wherein, W is a nitrogen atom and Y is absent or, W is a carbon atom and Y═H; R1to R7may be the same or different and are independently selected from hydrogen or straight, branched or cyclic C1-6alkyl; R8is a substituted heterocyclic group or a substituted aromatic group Ar is an aromatic or heteroaromatic ring each optionally substituted at single or multiple, non-linking positions with electron-donating or withdrawing groups; n and n′ are independently, 0-2; X is a group of the formula: Wherein, Ring A is an optionally substituted, saturated or unsaturated 5 or 6-membered ring, and P is an optionally substituted carbon atom, an optionally substituted nitrogen atom, sulfur or oxygen atom. Ring B is an optionally substituted 5 to 7-membered ring. Ring A and Ring B in the above formula can be connected to the group W from any position via the group V, wherein V is a chemical bond, a (CH2)n″group (where n″=0-2) or a C═O group. Z is, (1) a hydrogen atom, (2) an optionally substituted C1-6alkyl group, (3) a C0-6alkyl group substituted with an optionally substituted aromatic or heterocyclic group, (4) an optionally substituted C0-6alkylamino or C3-7cycloalkylamino group, (5) an optionally substituted carbonyl group or sulfonyl. These compounds further include any pharmaceutically acceptable acid addition salts and metal complexes thereof and any stereoisomeric forms and mixtures of stereoisomeric forms thereof.
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Page column 41-42
(2008/06/13)
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- Sulfuric acid on silica-gel: An inexpensive catalyst for aromatic nitration
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Solid acidic catalysts made of sulfuric acid supported on silica-gel and their application to the nitration of aromatics with nitric acid and isopropyl nitrate are described. Substrates with very different levels of activation were investigated. Methods to overcome the poisoning produced by water and to tune the catalysts activity according to the reactivity of the substrate are outlined.
- Riego, Juan M.,Sedin, Zeno,Zaldivar, Jose M.,Marziano, Nunziata C.,Tortato, Claudio
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p. 513 - 516
(2007/10/02)
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- NUCLEOPHILIC HETEROAROMATIC SUBSTITUTIONS. XXXIX. THE REACTION OF α- AND γ-- AND α- AND γ--7-NITROQUINOLINE WITH PIPERIDINE IN BENZONITRILE: BASE CATALYSIS AND O vs S REACTIVITY
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The reactivity of the title compounds with piperidine has been examined.Product analysis showed that substitution is accompanied by other processes, the extent of which depends on the reactivity of the substrates towards nucleophilic substitution and is greatest in the case of the γ-arylthio derivative, which does not undergo substitution at all.Accordingly, a kinetic analysis of the reaction could be performed only for the two aryloxy and the α-arylthio derivatives.Second-order rate coefficients for the reactions of the α-substituted quinolines were found to be independent of amine concentration and the α-aryloxy derivative was found to be only ca 4 times as reactive as the α-arylthio compound.In contrast, the reaction of the γ-aryloxy derivative followed third-order kinetics and turned out to be base-catalysed because it was accelerated by added quinuclidine.The reaction mechanisms are discussed in the light of these observations and other, previously reported, facts.
- Cidda, Claudio,Sleiter, Giancarlo
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p. 155 - 162
(2007/10/02)
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- Process for the production of nitro derivatives of aromatic compounds
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Nitroderivates of aromatic compounds which are difficult to nitrate, can readily be obtained by nitration providing that the aromatic compound is treated with nitric acid or another nitrating agent in the presence of aliphatic or cycloaliphatic hydrocarbons monosubstituted or polysubstituted by halogen, the nitro group or an alkyl sulphonyl group, and the nitro derivative formed subsequently isolated.
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