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Showing 1 to 20 of 57 for “"Cyclopropane"”.
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Anion Relay Cyclopropanation and Aryl Vinyl Cyclopropane Cope Rearrangements
… to effect anion relay in the synthesis of vinyl cyclopropanes, and subsequent aromatic Cope rearrangement of those vinyl cyclopropanes. This protocol provides a supplementary method of anion relay utilizing readily accessible nucleophiles, which obviates the need for synthesis of alkyl silanes or …
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Radical rearrangement in the spiro(cyclopropane-1,1'-indan) and 3',4'-dihydrospiro(cyclopropane-1,1'(2H)-naphthalene) systems. An investigation of fast radical clocks
… tin hydride method. At 75$\sp\circ$C, the spiro (cyclopropane-1,1$\sp\prime$-indan) -2$\sp\prime$-yl and 3$\sp\prime$,4$\sp\prime$-dihydrospiro (cyclopropane-1,1$\sp\prime$(2$H$)-naphthalene) -2$\sp\prime$-yl radicals undergo ring opening with rate constants of 2.11 $\times$ 10$\sp9$ s$\sp{-1}$ …
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The generation and reactivity of functionalised organozinc carbenoids for cyclopropane synthesis
… of functionalised organozinc carbenoids for cyclopropane synthesis with alkenes. In the introductory chapter, a brief overview of the different methods for preparation of heteroatom-functionalised cyclopropanes is presented, including [2+1] cycloaddition reactions using a carbene or carbenoid …
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The Stereochemistry of Homolytic and Electrophilic Displacements on The Cyclopropane Ring
Made available in DSpace on 2014-12-05T19:37:25Z (GMT). No. of bitstreams: 1 6001675.pdf: 5258263 bytes, checksum: 84b95a1d6bd796b6db9a1f483cc0a542 (MD5) Previous issue date: 1960
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Intermolecular Carbon-13 Kinetic Isotope Effect in the Thermal Structuralisomerization of Cyclopropane
Made available in DSpace on 2014-12-09T17:35:48Z (GMT). No. of bitstreams: 1 6711922.pdf: 6434035 bytes, checksum: 0833c7069c2960fd1a7276501a99f19b (MD5) Previous issue date: 1967
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The kinetics of the deactivation of a nickel catalyst during the hydrogenation of cyclopropane,
Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Chemical Engineering, 1968.
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Stress relief: Exercising Lewis acid catalysis for donor-acceptor cyclopropane ring-opening annulations, a basis for new reaction methodologies
… to assemble diverse polycycles, donor-acceptor cyclopropanes are useful, versatile synthetic equivalents for C-C bond formations. By taking advantage of the strain within these unique, polarized systems, differing molecular architectures can be accessed directly to perform contemporary organic …
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Synthesis of Cyclopropane-Fused 1,5-Diazocin-2-ones via Metal-Templated Intramolecular Addition of Nitrogen Nucleophiles to Pre-Generated Cyclopropenes
… by which to access compounds possessing the 3,4-cyclopropane-annulated 1,5-diazocin-2-one scaffold. The methods described herein are based on the intramolecular nucleophilic addition of nitrogen nucleophiles to the cyclopropene double bond in a direct 8-membered cyclization. This method allows …
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Reactions of a super-electron donor with diarylcyclopropanes and epoxides
… donor 1.57. The geometric isomerisation of diarylcyclopropanes was also achieved by DMAP-derived electron donor 1.57. Both geometric isomers of 1,2-bis(4-fluorophenyl)cyclopropane and 1,2- diphenylcyclopropane were isomerised when submitted to 1.57 (Scheme 2). However, no complete isomerisation …
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The Study of Various Hydrogen-Bonded Complexes Using Pulsed, Fourier-Transform Fabry-Perot Microwave Techniques
… rotational Zeeman effect for complexes involving cyclopropane gives additional electronic distribution information for the complexes and is shown to indirectly give magnetic properties for cyclopropane. The complexes discussed include complexes between cyclopropane and HCl, HF, and HCN and …
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The Chemistry of Cyclopropylarene Radical Cations
Cyclopropane derivatives are frequently utilized as "probes" for radical cation intermediates in a number of important chemical and biochemical oxidation. The implicit assumption in such studies is that if a radical cation is produced, it will undergo ring opening. Through a detailed examination of …
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A Study of the Structure Of 1,1,2,2-Tetracyanocyclopropane-Methanol Adduct
… addition to occur between a nucleophile and a cyclopropane, it was necessary for the cyclopropane to contain two activating groups, such as -COCR or -CN. The initial intent of this research was to investigate the possibility of similar reactions with 1,1,2,2- tetracyanocyclopropanes. However, …
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Synthesis and Evaluation of Aziridine Analogs of Presqualene Diphosphate as Squalene Synthase Inhibitors
… may indicate a bridged non-classical, protonated cyclopropane intermediate in the formation of presqualene diphosphate.
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A preliminary study of the characteristic physical properties of chlorinated asphalt
… lowest member of the series, cyclopropane has the structural formula: [see PDF file for formula]</p><p>This series is “saturated”, but “unsaturated compounds with a similar structure can occur. Such a compound would be cyclopropane, [see PDF file for formula]</p>
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Fused and spiro furanones from tetronic acid synthons: Oxa and azacycles featuring the butenolide ring
… Conia reaction produced the corresponding spiro cyclopropane furan-2,4-diones. Nucleophilic ring opening with diverse alcohols converted the spiro cyclopropane furan-2,4-diones to 3-beta-alkyloxypropyltetronic acids. When using O-benzyl isourea for the 4-O-alkylation of 3-allyl tetronic acids, …
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Understanding the physiological role of the small RNA RydC
… RydC was previously shown to stabilize cfa (cyclopropane fatty acid synthase) mRNA, resulting in higher levels of cyclopropane fatty acids in the cell membrane. Here, we show that additional sRNAs, ArrS and CpxQ, also directly regulate cfa post-transcriptionally. RydC and ArrS act through …
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The rearrangement of cyclopropyl carbenes
… - 140° in an alkaline aprotic medium.<br/><br/>Cyclopropane carboxaldehyde p-toluene sulphonyl hydrazone itself gives rise mainly to cyclobutene. The direction of ring opening has been determined from a study of asymmetrically substituted cyclopropyl carbenes, The substitution pattern in the …
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Development of New N-Cyclopropyl Based Electron Transfer Probes for Cytochrome P-450 and Monoamine Oxidase Catalyzed Reactions
… opening pathway. Therefore a new series of spiro cyclopropanes were designed to lock the cyclopropyl group into the appropriate bisected conformation. The electrochemical results reported herein show that the rate constant for ring opening of …
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A Nanosecond Laser Spectrophotometric and Product Investigation of the Chemistry of Fluorenylidene
… been studied in hexafluorobenzene, cyclohexane, cyclopropane, spiropentane, acetonitrile, and Freon 113 spectroscopically, and chemically by isolation and characterization of products. Proposal of an equilibrium between singlet and triplet fluorenylidene has been made. Evidence has also been …
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