- Deoxyfluorination with CuF2: Enabled by Using a Lewis Base Activating Group
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Deoxyfluorination is a primary method for the formation of C?F bonds. Bespoke reagents are commonly used because of issues associated with the low reactivity of metal fluorides. Reported here is the development of a simple strategy for deoxyfluorination, using first-row transition-metal fluorides, and it overcomes these limitations. Using CuF2 as an exemplar, activation of an O-alkylisourea adduct, formed in situ, allows effective nucleophilic fluoride transfer to a range of primary and secondary alcohols. Spectroscopic investigations have been used to probe the origin of the enhanced reactivity of CuF2. The utility of the process in enabling 18F-radiolabeling is also presented.
- Bode, Bela E.,Chabbra, Sonia,Champion, Sue,Dawson, Daniel M.,Sood, D. Eilidh,Sutherland, Andrew,Watson, Allan J. B.
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supporting information
p. 8460 - 8463
(2020/04/10)
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- Can Accelerated Reactions in Droplets Guide Chemistry at Scale?
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Mass spectrometry (MS) is used to monitor chemical reactions in droplets. In almost all cases, such reactions are accelerated relative to the corresponding reactions in bulk, even after correction for concentration effects, and they serve to predict the likely success of scaled-up reactions performed in microfluidic systems. The particular chemical targets used in these test studies are diazepam, atropine and diphenhydramine. In addition to a yes/no prediction of whether scaled-up reaction is possible, in some cases valuable information was obtained that helped in optimization of reaction conditions, minimization of by-products, and choice of catalyst. In a variant on the spray-based charged droplet experiment, the Leidenfrost effect was used to generate larger, uncharged droplets and the same reactions were studied in this medium. These reactions were also accelerated but to smaller extents than in microdroplets, and they gave results that correspond even more closely to microfluidics data. The fact that MS was also used for online reaction monitoring in the microfluidic systems further enhances the potential role of MS in exploratory organic synthesis.
- Wleklinski, Michael,Falcone, Caitlin E.,Loren, Bradley P.,Jaman, Zinia,Iyer, Kiran,Ewan, H. Samuel,Hyun, Seok-Hee,Thompson, David H.,Cooks, R. Graham
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p. 5480 - 5484
(2016/11/26)
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- Synthesis of ipratropium bromide-related compounds
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Synthesis of ipratropium bromide metabolites is described. Copyright Taylor & Francis Group, LLC.
- Tsyskovskaia, Irina,Kandil, Mustapha,Beaumier, Yves
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p. 439 - 446
(2007/10/03)
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- Analysis and stability of atropine sulfate and scopolamine hydrobromide. 1. Qualitative detection of alkaloids in the presence of their decomposition products. 73. Contribution to the problem of the use of plastic receptacles for liquid pharmaceuticals
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The authors deal with the qualitative determination of tropane alkaloid salts (atropine sulphate and scopolamine hydrobromide) in aqueous solutions in the presence of their decomposition products using thin-layer chromatography. Aqueous solutions of these tropane alkaloid salts were tested for stability after storage in glass and polyethylene containers under various conditions (pH value, temperature, ultra-violet irradiation, oxidative effects). Besides tropine, apoatropine, alpha- and beta-belladonine, further decomposition products showing a basic reaction (and in part not yet identified) were detected. The stability of solid atropine sulphate was studied by means of differential thermal analysis and mass spectrometry.
- Jira,Pohloudek-Fabini
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p. 645 - 649
(2007/10/02)
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