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Guanwu Wang - One of the best experts on this subject based on the ideXlab platform.
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synthesis of ortho acid ester type 1 3 dioxolanofullerenes Radical Reaction of 60 fullerene with halocarboxylic acids promoted by lead iv acetate
Journal of Organic Chemistry, 2014Co-Authors: Xun You, Guanwu WangAbstract:A lead(IV) acetate-promoted Radical Reaction of [60]fullerene with halocarboxylic acids has been exploited to synthesize rare ortho acid ester-type 1,3-dioxolanofullerenes, the hydroxyl group of which can be further transformed to an ester or ether group. Intriguingly, an ortho acid ester-type 1,3-dioxolanofullerene can also be converted to a 1,4-dioxanonofullerene in the presence of a base or manipulated to another ortho acid ester-type 1,3-dioxolanofullerene by Reaction with a stronger halocarboxylic acid. Moreover, two possible Reaction pathways leading to the observed products are also proposed.
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synthesis of 60 fullerene fused tetrahydronaphthalene and indane derivatives via a pathway switched by aluminum chloride
Organic Letters, 2011Co-Authors: Tongxin Liu, Guanwu WangAbstract:The addition of aluminum chloride to the manganese acetate-mediated Radical Reaction of [60]fullerene with 2-arylmalonates, 2-benzylmalonates, and 2-arylcyanoacetates can switch the Reaction pathway and affords a variety of structurally novel and scarce [60]fullerene-fused tetrahydronaphthalene and indane derivatives. These products are formed probably through Radical addition, followed by Friedel–Crafts-type annulation.
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Radical Reaction of 60 fullerene with phosphorus compounds mediated by manganese iii acetate
Journal of Organic Chemistry, 2011Co-Authors: Guanwu Wang, Congzhou WangAbstract:Radical Reaction of [60]fullerene with phosphonates or phosphine oxide mediated by manganese(III) acetate dihydrate in chlorobenzene under three different conditions afforded three different types of phosphorylated fullerenes: singly bonded fullerene dimers 2, hydrophosphorylated fullerenes 3, and acetoxylated fullerene derivatives 4. In addition, interconversions among the three types of phosphorylated fullerene derivatives have also been investigated. A possible Reaction mechanism was proposed to explain experimental results.
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manganese iii acetate mediated Radical Reaction of 60 fullerene with phosphonate esters affording unprecedented separable singly bonded 60 fullerene dimers
Chemical Communications, 2011Co-Authors: Guanwu Wang, Congzhou Wang, Sane Zhu, Yasujiro MurataAbstract:Radical Reaction of [60]fullerene with phosphonate esters mediated by manganese(III) acetate in chlorobenzene afforded singly-bonded fullerene dimers, of which the individual meso and racemic isomers could be unexpectedly separated out for the first time.
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synthesis of fullerene fused lactones and fullerenyl esters Radical Reaction of 60 fullerene with carboxylic acids promoted by manganese iii acetate and lead iv acetate
Journal of Organic Chemistry, 2009Co-Authors: Tongxin Liu, Yongshun Huang, Guanwu WangAbstract:The manganese(III) acetate-mediated Radical Reaction of [60]fullerene with carboxylic acids in the presence of 4-(dimethylamino)pyridine exclusively afforded the [60]fullerene-fused lactones. Interestingly, the lead(IV) acetate-promoted Radical Reaction of [60]fullerene with the same carboxylic acids selectively gave another type of fullerene products, i.e., fullerenyl esters. Possible mechanisms for the formation of fullerene products are proposed.
Nadim Darwish - One of the best experts on this subject based on the ideXlab platform.
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metal single molecule semiconductor junctions formed by a Radical Reaction bridging gold and silicon electrodes
Journal of the American Chemical Society, 2019Co-Authors: Chandramalika R Peiris, Yan B Vogel, Anton Le P Brun, Albert C Aragones, Ismael Diezperez, Michelle L. Coote, Simone Ciampi, Nadim DarwishAbstract:Here we report molecular films terminated with diazonium salts moieties at both ends which enables single-molecule contacts between gold and silicon electrodes at open circuit via a Radical Reaction. We show that the kinetics of film grafting is crystal-facet dependent, being more favorable on ⟨111⟩ than on ⟨100⟩, a finding that adds control over surface chemistry during the device fabrication. The impact of this spontaneous chemistry in single-molecule electronics is demonstrated using STM-break junction approaches by forming metal–single-molecule–semiconductor junctions between silicon and gold source and drain, electrodes. Au–C and Si–C molecule–electrode contacts result in single-molecule wires that are mechanically stable, with an average lifetime at room temperature of 1.1 s, which is 30–400% higher than that reported for conventional molecular junctions formed between gold electrodes using thiol and amine contact groups. The high stability enabled measuring current–voltage properties during the lif...
Roger Atkinson - One of the best experts on this subject based on the ideXlab platform.
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estimation of hydroxyl Radical Reaction rate constants for gas phase organic compounds using a structure reactivity relationship an update
Atmospheric Environment, 1995Co-Authors: Eric S C Kwok, Roger AtkinsonAbstract:Abstract The structure-reactivity approach proposed by Atkinson (1986, Chem. Rev. 86 , 69-201) and extended by Atkinson (1987, Int. J. Chem. Kinet. 19 , 799-828) for the calculation of rate constants for the gas-phase Reactions of the OH Radical with organic compounds has been re-investigated using the presently available database. Substituent group factors for several new groups are derived, including those for fluorinated eithers. Using a large fraction of the available database to derive the parameters needed to calculate the OH Radical Reaction rate constants, the 298 K rate constants of ∼90% of approximately 485 organic compounds are predicted to within a factor of 2 of the experimental values. Disagreements between calculated and experimental rate constants most commonly occur for halogen-containing compounds, and in particular for haloalkanes, haloalkenes and halogenated ethers. Disagreements also arise for ethers, especially for polyethers and cycloethers. The present estimation technique is reasonably reliable when used within the database used in its derivation, but extrapolation to organic compounds outside of this database results in a lack of assurance of its reliability, and its use for organic compounds which belong to classes other than those used in its development is discouraged.
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product formation from the gas phase Reactions of oh Radicals and o3 with a series of monoterpenes
Journal of Atmospheric Chemistry, 1994Co-Authors: Hannele Hakola, Janet Arey, Sara M Aschmann, Roger AtkinsonAbstract:The formation yields of nine carbonyl products are reported from the gas-phase OH Radical-initiated Reactions (in the presence of NO x ) and the O3 Reactions with seven monoterpenes. The products were identified using GC/MS and GC-FTIR and quantified by GC-FID analyses of samples collected on Tenax solid adsorbent cartridges. The identities of products from camphene, limonene and β-pinene were confirmed by comparison with authentic standards. Sufficient quantities of products from the 3-carene, limonene, α-pinene, sabinene and terpinolene Reactions were isolated to allow structural confirmation by proton NMR spectroscopy. The measured total carbonyl formation yields ranged from non-detectable for the OH Radical Reaction with camphene and the O3 Reactions with 3-carene and limonene to ∼0.5 for the OH Radical Reaction with limonene and the O3 Reaction with sabinene.
Giuseppe Zanardi - One of the best experts on this subject based on the ideXlab platform.
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tin free generation of alkyl Radicals from alkyl 4 pentynyl sulfides via homolytic substitution at the sulfur atom
Organic Letters, 2008Co-Authors: Giorgio Bencivenni, Tommaso Lanza, Matteo Minozzi, Piero Spagnolo, Rino Leardini, Daniele Nanni, Giuseppe ZanardiAbstract:Homolytic substitution at the sulfur atom of β-(phenylsulfanyl)vinyl Radicals, obtained by Radical Reaction of benzenethiol with easily accessible alkyl 4-pentynyl sulfides, is a mild, effective, tin-free route for the generation of all types of alkyl Radicals. This protocol can be employed in reductive defunctionalizations as well as cyclizations onto both electron-rich and electron-poor C−C double bonds.
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tin free generation of alkyl Radicals from alkyl 4 pentynyl sulfides via homolytic substitution at the sulfur atom
Organic Letters, 2008Co-Authors: Giorgio Bencivenni, Tommaso Lanza, Matteo Minozzi, Piero Spagnolo, Rino Leardini, Daniele Nanni, Giuseppe ZanardiAbstract:Homolytic substitution at the sulfur atom of beta-(phenylsulfanyl)vinyl Radicals, obtained by Radical Reaction of benzenethiol with easily accessible alkyl 4-pentynyl sulfides, is a mild, effective, tin-free route for the generation of all types of alkyl Radicals. This protocol can be employed in reductive defunctionalizations as well as cyclizations onto both electron-rich and electron-poor C-C double bonds.
Marianna Pierobon - One of the best experts on this subject based on the ideXlab platform.
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emergence of a novel catalytic Radical Reaction titanocene catalyzed reductive opening of epoxides
Journal of the American Chemical Society, 1998Co-Authors: Andreas Gansauer, Harald Bluhm, Marianna PierobonAbstract:The preparatively important catalytic opening of epoxides to β-titanoxy Radicals via single-electron transfer (SET) is described. These Radicals can be reduced to alcohols or participate in C−C bond-forming Reactions. A key step in the catalytic cycle is the conceptually novel protonation of titanium−oxygen and −carbon bonds. Our method combines the advantages of Radical Reactions, e.g., high functional group tolerance and stability of Radicals under protic conditions, with the ability of organometallic complexes to determine the course of transformations in reagent-controlled Reactions.
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emergence of a novel catalytic Radical Reaction titanocene catalyzed reductive opening of epoxides
Journal of the American Chemical Society, 1998Co-Authors: Andreas Gansauer, Harald Bluhm, Marianna PierobonAbstract:The preparatively important catalytic opening of epoxides to β-titanoxy Radicals via single-electron transfer (SET) is described. These Radicals can be reduced to alcohols or participate in C−C bond-forming Reactions. A key step in the catalytic cycle is the conceptually novel protonation of titanium−oxygen and −carbon bonds. Our method combines the advantages of Radical Reactions, e.g., high functional group tolerance and stability of Radicals under protic conditions, with the ability of organometallic complexes to determine the course of transformations in reagent-controlled Reactions.
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catalytic highly regio and chemoselective generation of Radicals from epoxides titanocene dichloride as an electron transfer catalyst in transition metal catalyzed Radical Reactions
Angewandte Chemie, 1998Co-Authors: Andreas Gansauer, Marianna Pierobon, Harald BluhmAbstract:Sensitive functional groups like halides, ketones, or tosylates pose no difficulties in the new, [Cp2TiCl2]-catalyzed, Radical Reaction [Eq. (1)]. The conversions proceed with excellent chemoselectivity, which in many cases is complementary to that of established Reactions.