- Contra-thermodynamic Olefin Isomerization by Chain-Walking Hydrofunctionalization and Formal Retro-hydrofunctionalization
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We report a contra-thermodynamic isomerization of internal olefins to terminal olefins driven by redox reactions and formation of Si-F bonds. This process involves chain-walking hydrosilylation of internal olefins and subsequent formal retro-hydrosilylation. The process rests upon the high activities of platinum hydrosilylation catalysts for isomerization of metal alkyl intermediates and a new, metal-free process for the conversion of alkylsilanes to alkenes. By this approach, 1,2-disubstituted and trisubstituted olefins are converted to terminal olefins.
- Hanna, Steven,Butcher, Trevor W.,Hartwig, John F.
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supporting information
p. 7129 - 7133
(2019/09/12)
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- Application of "click" chemistry in solid phase synthesis of alkyl halides
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A convenient and highly selective microwave assisted procedure for the conversion of allylic, benzylic and aliphatic alcohols to their corresponding halides using polymer-bound triphenylphosphine and iodine is presented. In case of symmetrical diols, mono-iodination product is obtained in very high yield. Additionally, highly regioselective behavior is observed in our procedure. Simplicity in operation, no column chromatography required for the purification of the products, recyclability of the reagents used, short reaction times and good to excellent yields are the advantages of our protocol. Most functional groups remain unaffected under our reaction condition.
- Das, Diparjun,Chanda, Tridib,Rokhum, Lalthazuala
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p. 775 - 783
(2016/01/20)
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- Synthesis of 6-thio pseudo glycolipids and their orientation on a gold slide studied by IRRAS
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We have synthesized four 6-thio pseudo glycolipid analogues and assessed how two of them self-assembled on a gold surface. These structures were designed as candidate tethers molecules to anchor bilayer lipid membranes on gold. 6-Deoxy-6-thiogalactose was chosen to anchor the macromolecule to the gold and define an aqueous zone at the gold surface. A long alkane chain (C-12 or C-18) linked to the anomeric position of the sugar residue was chosen to anchor a bilayer lipid membrane. The linkage between the carbohydrate and the hydrophobic chains is either a glycosidic bond or a 1,4-disubstituted triazole formed by copper(I)-catalysed alkyne-azide cycloaddition (CuAAC) of the propargyl glycoside with azido-dodecane and azido-octadecane. We are expecting that the hydrocarbon chains will orient themselves perpendicular to the gold surface and be incorporated into the first leaflet of the bilayer membrane. We have studied self assembled monolayers of the C-12 aglycone analogues on gold using infrared reflection absorption spectroscopy (IRRAS). We compared the results given by the IRRAS experiments to the IR spectra recorded by attenuated total reflection (ATR) spectroscopy on films of the randomly oriented analogues. Our results demonstrate that the C-12 analogues did bind to gold and did orient themselves perpendicular to the gold slide.
- Guillemineau, Mickael,Singh, Serena,Grossutti, Michael,Auzanneau, France-Isabelle
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experimental part
p. 2723 - 2730
(2011/03/17)
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- The fluid-mosaic model, homeoviscous adaptation, and ionic liquids: Dramatic lowering of the melting point by side-chain unsaturation
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(Figure Presented) Defying conventional wisdom: Ionic liquids (ILs) with long, unsaturated alkyl appendages (see top structure) defy established trends that link long ion-bound alkyl groups to higher melting points. The new ILs are also less viscous than a saturated standard (see bottom structure) at the same temperature. These features parallel those that underpin homeoviscous adaptation in certain organisms and are indirectly supportive of a fluid-mosaiclike nanoscale character.
- Murray, Samuel M.,O'Brien, Richard A.,Mattson, Kaila M.,Ceccarelli, Christopher,Sykora, Richard E.,West, Kevin N.,Davis Jr., James H.
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body text
p. 2755 - 2758
(2010/07/06)
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- Anti-cancer nitro- and thia-fatty acids
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The present invention relates to pharmaceutical compositions comprising, as an anti-cancer agent: (a) one or more compounds having the formula NO2-A-B, wherein A is a saturated or unsaturated hydrocarbon chain of 14-26 double bonds, and B is (CH2)m(COOH)n in which n is a integer from 0 to 2 and m is an integer from 0 to 2; or a derivative thereof in which the hydrocarbon chain has one or more than one substitution selected from the group consisting of hydroxy, hydroperoxy, epoxy and peroxy; (b) one or more compounds selected from polyunsaturated fatty acids (PUFA's) having a 16 to 26 carbon atom chain and 3 to 16 double bonds, and wherein the PUFA is covalently coupled at the carboxylic acid group to an amino acid selected from glycine and aspartic acid; (c) one or more compounds selected from unsaturated fatty acids having an 18 to 25 carbon atom chain and 1 to 6 double bonds and wherein the fatty acid has one or two beta-oxa, gamma-oxa, beta-thia, gamma-thia substitutions: or (d) one or more compounds having formula (I) wherein A' is a saturated or unsaturated hydrocarbon chain of 9-26 carbon atoms, X is oxygen or is absent and B' is (CH2)J(COOH)k in which j is an integer from 1 to 3 and K is 0 or 1; or a derivative thereof in which the hydrocarbon chain has one or more than one substitution selected from the group consisting of hydroxy, hydroperoxy, epoxy and peroxy; and a pharmaceutically acceptable carrier or diluent.
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- Polyunsaturated nitroalkanes and nitro-substituted fatty acids
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Nitroalkanes 4 are readily prepared from naturally derived polyunsaturated fatty alcohols 1 via succesive conversion to the corresponding haloalkanes 2 and 3, and reaction with silver nitrite. Reaction of nitroalkanes 4a,b with methyl acrylate, followed by ester hydrolysis, affords nitro-substituted fatty acids 6a,b and 8a,b. Oxidation of alcohols 1a,b gives the corresponding aldehydes 9a,b, which react by Henry condensation with nitromethane to give β-hydroxynitroalkanes 10a,b.
- Easton,Xia,Pitt,Ferrante,Poulos,Rathjen
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p. 451 - 457
(2007/10/03)
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- A FACILE PROCEDURE FOR THE DIRECT CONVERSION OF ETHERS TO ALKYL IODIDES
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Treatment of ethers with phenyl dichlorophosphate and sodium iodide in refluxing xylenes or acetonitrile resulted in the cleavage of the ether linkage leading to the formation of alkyl iodides.
- Liu, Hsing-Jang,Wiszniewski, Virginia
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p. 119 - 124
(2007/10/02)
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- β-Cyclodextrin-Epichlorohydrin Copolymers as Efficient Catalysts in Phase-Transfer-Catalyzed Nucleophilic Substitution Reactions
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Copolymers of β-cyclodextrin (β-CD) with epichlorohydrin showed much higher phase-transfer catalytic activity than β-CD in liquid-liquid two-phase nucleophilic displacement reactions.The enhanced efficiency of the polymer catalysts was attributed to the cooperative effect of more than one β-CD group in polymers in bringing a substrate from an organic phase to an aqueous phase.
- Tanaka, Nobuo,Yamaguchi, Atsumi,Araki, Yoshio,Araki, Mikio
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p. 715 - 718
(2007/10/02)
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