A quantitative reactivity scale for electrophilic fluorinating reagents. Issue 46 (24th September 2018)

• Record Type: Journal Article
• Authors: Rozatian, Neshat; Ashworth, Ian W.; Sandford, Graham; Hodgson, David R. W.
• Is Part Of: Chemical science. Volume 9:Issue 46(2018)
• Page Start: 8692
• Page End: 8702
• Publication Date: 2018-09-24
• Subjects: Chemistry -- Periodicals; 540.5
• DOI: 10.1039/c8sc03596b
• Languages: English
• ISSNs: 2041-6520

Abstract

Abstract : Through kinetic studies we provide a quantitative reactivity scale for ten electrophilic fluorination reagents. Abstract : Electrophilic N–F fluorination agents underpin the introduction of fluorine in aliphatic systems across drug and academic research. The choice of N–F reagent is currently determined through empirical experimentation in the absence of quantitative values for electrophilicities. Here we report an experimentally-determined kinetic reactivity scale for ten N–F fluorinating reagents, including Selectfluor™, NFSI, Synfluor™ and several N -fluoropyridinium salts, in CH3 CN. The reactivity scale, which covers eight orders of magnitude, employs para -substituted 1, 3-diaryl-1, 3-dicarbonyl derivatives to measure relative and absolute rate constants. The para -substituted 1, 3-diaryl-1, 3-dicarbonyl scaffold delivers a convenient, sensitive spectrophotometric reporter of reactivity that also led to the discovery of a unique form of tautomeric polymorphism.