- A simple and direct access to ethylidene malonates
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The condensation of active methylene compounds 1 with acetaldehyde was efficiently promoted by a catalytic amount of lithium bromide in the presence of acetic anhydride to give ethylidene malonates 2 in 77-97% yield. Georg Thieme Verlag Stuttgart.
- Sylla, Maite,Joseph, Delphine,Chevallier, Emilie,Camara, Cheikhou,Dumas, Francoise
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- Design, synthesis, and biological evaluation of some novel indolizine derivatives as dual cyclooxygenase and lipoxygenase inhibitor for anti-inflammatory activity
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Some novel indolizine derivatives were synthesized by bioisosteric modification of imidazo[1,2-a]pyridine for anti-inflammatory activity. The physicochemical characterization and structure of compounds were elucidated by state of the art spectroscopic technique. Induced fit docking was performed for initial screening to elucidate the interactions with corresponding amino acids of cyclooxygenase (COX-1, COX-2) and lipoxygenase (LOX) enzymes. The target compounds 53–60 were then evaluated against in vivo carrageenan and arachidonic acid induced rat paw edema models for anti-inflammatory activity. Amongst all the synthesized derivatives, compound 56 showed the significant anti-inflammatory activity in both rat paw edema models with very less ulcerogenic liability in comparison to standard diclofenac, celecoxib, and zileuton. The compounds 56 was further assessed to observe in vitro enzyme inhibition assay on both cyclooxygenase and lipoxygenase enzyme where it showed a preferential and selective non-competitive enzyme inhibition towards the COX-2 (IC50?=?14.91?μM, Ki?=?0.72?μM) over COX-1 (IC50?>?50?μM) and a significant non-competitive inhibition of soybean lipoxygenase enzyme (IC50?=?13.09?μM, Ki?=?0.92?μM). Thus, in silico, in vivo, and in vitro findings suggested that the synthesized indolizine compound 56 has a dual COX-2 and LOX inhibition characteristic and parallel in vivo anti-inflammatory activity in comparison to the standard drugs.
- Shrivastava, Sushant K.,Srivastava, Pavan,Bandresh, Robin,Tripathi, Prabhash Nath,Tripathi, Avanish
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- Acetal Addition to Electron-Deficient Alkenes with Hydrogen Atom Transfer as a Radical Chain Propagation Step
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We describe a visible-light-promoted addition of a hydrogen atom and an acetal carbon toward various electron-deficient alkenes. 1,3-Dioxolane is converted to its radical species in the presence of persulfate and an iridium catalyst upon visible light irradiation, which then reacts with electron-deficient alkenes. The reaction operates via a radical chain mechanism, a less commonly observed pathway for this class of transformation. Hydrogen atom transfer from 1,3-dioxolane to α-malonyl radicals is corroborated by experimental and density functional theory studies.
- Chan, Wei Chuen,Vinod, Jincy K.,Koide, Kazunori
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p. 3674 - 3682
(2021/02/16)
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- PYRIMIDONE DERIVATIVES AS SELECTIVE CYTOTOXIC AGENTS AGAINST HIV INFECTED CELLS
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The present disclosure is directed to pyrimidone derivatives of Formula I and their use for selectively killing HIV infected GAG-POL expressing cells without concomitant cytotoxicity to HIV nave cells, and for the treatment or prophylaxis of infection by HIV, or for the treatment, prophylaxis or delay in the onset or progression of AIDS or AIDS Related Complex (ARC).
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Page/Page column 57; 58
(2020/07/14)
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- Br?nsted Base-Mediated Aziridination of 2-Alkyl-Substituted-1,3-Dicarbonyl Compounds and 2-Acyl-Substituted-1,4-Dicarbonyl Compounds by Iminoiodanes
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The synthesis of α,α-diacylaziridines and α,α,β-triacylaziridines from reaction of 2-alkyl-substituted-1,3-dicarbonyl compounds and 2-acyl-substituted-1,4-dicarbonyl compounds with arylsulfonyliminoiodinanes (ArSO2N=IPh) under Br?nsted base-med
- Tejo, Ciputra,Tirtorahardjo, Davin,Day, David Philip,Ma, DIk-Lung,Leung, Chung-Hang,Chan, Philip Wai Hong
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p. 430 - 435
(2017/04/07)
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- Direct Photoredox-Catalyzed Reductive Difluoromethylation of Electron-Deficient Alkenes
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Photoredox-catalyzed reductive difluoromethylation of electron-deficient alkenes was achieved in one step under tin-free, mild and neutral conditions. This protocol affords a facile method to introduce RCF2 (R=H, Ph, Me, and CH2N3) groups at sites β to electron-withdrawing groups. It was found that TTMS (tris(trimethylsilyl)silane) served nicely as both the H-atom donor and the electron donor in the catalytic cycle. Experimental and DFT computational results provided evidence that RCF2 (R=H, Ph, Me) radicals are nucleophilic in nature.
- Tang, Xiao-Jun,Zhang, Zuxiao,Dolbier, William R.
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supporting information
p. 18961 - 18965
(2016/01/26)
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- Copper(II) triflate catalyzed amination and aziridination of 2-Alkyl substituted 1,3-dicarbonyl compounds
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A method to prepare α-acyl-β-amino acid and 2,2-diacyl aziridine derivatives efficiently from Cu(OTf)2 + 1,10-phenanthroline (1,10-phen)-catalyzed amination and aziridination of 2-alkyl substituted 1,3-dicarbonyl compounds with PhI=NTs is described. By taking advantage of the orthogonal modes of reactivity of the substrate through slight modification of the reaction conditions, a divergence in product selectivity was observed. In the presence of 1.2 equiv of the iminoiodane, amination of the allylic C-H bond of the enolic form of the substrate, formed in situ through coordination to the Lewis acidic metal catalyst, was found to selectively occur and give the β-aminated adduct. On the other hand, increasing the amount of the nitrogen source from 1.2 to 2-3 equiv was discovered to result in preferential formal aziridination of the C-C bond of the 2-alkyl substituent of the starting material and formation of the aziridine product.
- Ton, Thi My Uyen,Tejo, Ciputra,Tiong, Diane Ling Ying,Chan, Philip Wai Hong
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p. 7344 - 7350
(2012/06/16)
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- Bronsted base-modulated Regioselective Pd-catalyzed intramolecular aerobic oxidative amination of alkenes: Formation of seven-membered amides and evidence for allylic C-H activation
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A novel palladium-catalyzed intramolecular aerobic oxidative allylic C-H amination of olefins has been developed. Bronsted base can modulate the regioselectivity, favoring the formation of 7-membered rings. Mechanistic studies using deuterium-labeled substrates as probes support a rate-determining allylic C-H activation/irreversible reductive elimination pathway.
- Wu, Liang,Qiu, Shuifa,Liu, Guosheng
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supporting information; scheme or table
p. 2707 - 2710
(2009/10/10)
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- Mechanism for photodecomposition of naphtho[1,8-de][1,3] dithiin-1-bis(ethoxycarbonyl)methylides
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Naphtho[1,8-de][1,3]dithiin-1-bis(ethoxycarbonyl)methylides (3) were prepared by the reaction of naphtho[1,8-de]dithiins with diethyl diazomalonate in the presence of copper acetylacetonate. The sulfonium ylides 3 underwent photo-rearrangement giving olefin 5 quantitatively together with naphthalene-1,8-dithiole.
- Fujii, Takayoshi,Sakuragi, Hirochika,Furukawa, Naomichi
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p. 8039 - 8042
(2007/10/02)
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- SYNTHESIS OF DIETHYL ALKYLIDENEMALONATES BY THE REDUCTION OF C-ACYLMALONIC DIETHYL ESTERS
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Ethoxymagnesium diethyl malonate was acetylated with an acid chloride and the resulting esters of C-acylmalonic acid (3) were reduced with sodium borohydride in acetic acid.The obtained esters of 1-hydroxyalkylmalonic acid (4) were converted, without isolation, into the required alkylidenediethyl malonates (5) by dehydration with phosphorus pentachloride and triethylamine.
- Doleschall, Gabor
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p. 823 - 829
(2007/10/02)
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- Hydroxyalkylation and Lactone Formation from Dialkyl Malonate by Means of a EuIII/EuII Photoredox System
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A EuIII/EuII photoredox system in alcohol induced an effective hydroxyalkylation at an α-position of a dialkyl malonate.The alcohol adduct was then converted to the lactone.A step-by-step hydroxyalkylation mechanism was suggested in which the Eu ion is used as a photocatalyst and also as a condensation catalyst for the reaction of dialkyl malonates and aldehydes.
- Ishida, Akito,Yamashita, Shinya,Takamuku, Setsuo
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p. 2229 - 2231
(2007/10/02)
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- Stereochemical studies on the reactions catalyzed by the PLP-dependent enzyme 1-aminocyclopropane-1-carboxylate deaminase
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The stereochemical course of 1-aminocyclopropane-1-carboxylate deaminase which catalyzes the fragmentation of the cyclopropane substrate to alpha -ketobutyrate and ammonia has been unraveled with the help of substrates stereospecifically labeled with deuterium and/or tritium, and this has afforded important information about the process occurring at the active site during enzymatic conversion.
- Liu,Auchus,Walsh
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p. 5335 - 5348
(2007/10/07)
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- REACTIONS INVOLVING SELENIUM METAL AS AN ELECTROPHILE. 2. A GENERAL PROCEDURE FOR THE PREPARATION OF UNSATURATED β-DICARBONYL COMPOUNDS
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A variety of β-dicarbonyl compounds can be converted to the corresponding unsaturated derivatives in high yields.The process involves reaction of the β-dicarbonyl carbanion with Se metal, followed by alkylation with methyl iodide to form the methylseleno derivative and subsequent oxidative elimination.
- Liotta, Dennis,Saindane, Manohar,Barnum, Christopher,Ensley, Harry,Balakrishnan, Pattabiraman
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p. 3043 - 3046
(2007/10/02)
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