- Bis-triethylene Glycolic Crown-5-calix[4]arene: A Promoter of Nucleophilic Fluorination Using Potassium Fluoride
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We designed and synthesized a bis-triethylene glycolic crown-5-calix[4]arene (BTC5A) as a multifunctional promoter for nucleophilic fluorination using KF. The synergetic effect of the calix-crown moiety and ethylene glycols of BTC5A enabled KF to be easil
- Kang, Seok Min,Kim, Chul Hee,Lee, Kyo Chul,Kim, Dong Wook
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Read Online
- Unbalanced-Ion-Pair-Catalyzed Nucleophilic Fluorination Using Potassium Fluoride
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An unbalanced ion pair promoter (e.g., tetrabutylammonium sulfate), consisting of a bulky and charge-delocalized cation and a small and charge-localized anion, greatly accelerates nucleophilic fluorinations using easy handling KF. We also successfully converted an inexpensive and commercially available ion-exchange resin to the polymer-supported ion pair promoter (A26–SO42–), which could be reused after filtration. Moreover, A26–SO42– can be used in continuous flow conditions. In our conditions, water is well-tolerated.
- Hammond, Gerald B.,Li, Wangbing,Lu, Zhichao,Xu, Bo
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p. 9640 - 9644
(2021/12/14)
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- Pyrene-Tagged Alcoholic Ionic Liquids as Phase Transfer Catalysts for Nucleophilic Fluorination
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Functional group?activity relationships of pyrene-tagged ionic liquid (PTIL)-based organocatalysts for nucleophilic fluorination using alkali metal fluorides (MFs) are described, which demonstrate that the pyrene, oligoether and alcohol moieties on the imidazolium ring are vital for efficient catalysis. Further investigation of these findings led to the discovery of new strategy, which showed superior catalyst separation process, i.e., catalyst is effortlessly separated from the reaction mixture using reduced graphene oxide. The catalytic efficiency of the PTIL as a phase transfer catalyst was demonstrated by the high conversion of the reactants up to 98% fluorinated yield using MFs in CH3CN or t-amyl alcohol. Importantly, the catalyst not only enhanced the reactivity of bimolecular nucleophilic substitutions (SN2) within a short reaction time and reduces the formation of by-products but also affords high yield with easy isolation and separation under mild conditions.
- Taher, Abu,Kim, Dong Wook
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supporting information
p. 1140 - 1146
(2020/10/15)
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- Convenient Entry to 18F-Labeled Amines through the Staudinger Reduction
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Fluorine-18 possesses outstanding decay characteristics for positron emission tomography (PET) imaging. Therefore, it is ideally suited for clinical applications. As such, improved strategies to incorporate fluorine-18 into bioactive molecules are of utmo
- Stéen, E. Johanna L.,Shalgunov, Vladimir,Denk, Christoph,Mikula, Hannes,Kj?r, Andreas,Kristensen, Jesper L.,Herth, Matthias M.
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supporting information
p. 1722 - 1725
(2019/01/30)
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- Compounds for binding and imaging amyloid plaques and their use
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The present invention relates to novel compounds (3-aminopropen-1-ones) useful for binding and imaging beta amyloid deposits and their use in detecting or treating Alzheimer's disease and amyloidosis.
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Page/Page column 16
(2012/09/25)
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