- Facile synthesis of TEG-substituted 4-(N-methyl-N-Boc-amino)styrylpyridine and PET imaging agent [F]florbetapir ([F]AV-45)
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Triethylene glycol-substituted 4-(N-methyl-N-Boc-amino)styrylpyridine which can serve as key precursor for many monodentate and multidentate imaging agents for Aβ plaques in human brain has been readily synthesized with cost-effective starting materials. The important non-radioactive monodentate positron emission tomography agent [F]florbetapir ([F]AV-45) has also been prepared by our new method.
- Yao, Tuo,Li, Zhi
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supporting information
p. 422 - 427
(2018/02/06)
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- Amino substituted 4-pyridylbutadienes: Synthesis and fluorescence investigations
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Synthesis and spectroscopic investigations of a series of donor-π-acceptor systems containing pyridine as the electron withdrawing group and an amino derivative (dimethylamino, diphenylamino, carbazole and julolidine) as electron donating group, separated by a π-spacer are described. The effect of varying donors on absorption and emission properties was studied in different solvents. All the molecules investigated exhibit pronounced positive polarity dependent solvatochromic shifts of up to ~141 nm. Strong fluorescence quantum yields are also observed for dienes containing carbazole and diphenylamine donors. This behavior suggests the presence of highly polar emitting states as a result of π -π?intramolecular charge-transfer (ICT). The observations were corroborated by a linear relation of the fluorescence maximum (νmax) versus the solvent polarity function (Δf) from the Lippert-Mataga correlation. The emission lifetime shows a decay profile consistent with the formation of one species (1 and 3) and two species (2 and 4) in the excited state.
- Agnihotri, Harsha,Mahalingavelar, Paramasivam,Mande, Hemant,Ghalsasi, Prasanna,Kanvah, Sriram
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p. 341 - 348
(2015/09/07)
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- Continuous flow photocyclization of stilbenes-scalable synthesis of functionalized phenanthrenes and helicenes
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A continuous flow oxidative photocyclization of stilbene derivatives has been developed which allows the scalable synthesis of backbone functionalized phenanthrenes and helicenes of various sizes in good yields.
- Lefebvre, Quentin,Jentsch, Marc,Rueping, Magnus
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supporting information
p. 1883 - 1890
(2013/10/22)
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- Facile C-N cleavage in a series of bridged lactams
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A series of strained bi- and tricyclic amides has been shown to be unusually sensitive to cleavage of the C-N bond adjacent to the amide moiety. This bond undergoes facile breaking when subjected to treatment with H2/Pd(OH)2, MeI, and DDQ. In each case, the reaction is highly regioselective and mainly results in breaking the C-N bond that deviates the farthest from its natural planar state. Preliminary experiments that bear on the mechanisms of these reactions are described. Copyright
- Lei, Yao,Wrobleski, Aaron D.,Golden, Jennifer E.,Powell, Douglas R.,Aube, Jeffrey
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p. 4552 - 4553
(2007/10/03)
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- Synthesis of aryl(difluoromethylenephosphonates) via electrophilic fluorination of α-carbanions of benzylic phosphonates with N- fluorobenzenesulfonimide.
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The electrophilic fluorination of a wide variety of benzylic phosphonates with N-fluorobenzenesulfonimide has been examined. The fluorination reaction proceeds well in the presence of an array of functional groups such as nitro, bromo, ketone, ester, phenyl and ether groups. Phenyl and biphenyl derivatives containing two α,α-difluoromethylenephosphonate groups can also be prepared. This procedure is compatible with methyl or ethyl phosphonate esters but not with t-butyl esters or with benzylic phosphonates containing an additional benzylic moiety at the para-position.
- Taylor, Scott D.,Kotoris, Christopher C.,Dinaut, A. Nicole,Chen, Mei-Jin
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p. 1691 - 1714
(2007/10/03)
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- Reactivity of the acids of trivalent phosphorus and their derivatives. Part VI. The reaction of the >P-O- anions with benzyl bromides para-substituted in the phenyl ring
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The reaction of p-substituted benzyl bromides with the >P-O- ions in THF, alcohols and toluene as the solvents is described. According to the reduction potential of the p-substituted benzyl bromides and the solvent used the formation of the P-C bond, debromination and/or dimerization occur. The principal process is believed to be X-philic substitution, the dimers are formed through a secondary process via SET from the p-substituted benzyl anions into the p-substituted benzyl bromides.
- Witt, Dariusz,Rachon, Janusz
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p. 169 - 187
(2007/10/03)
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