N-fluoropyridinium pyridine heptafluorodiborate: a useful fluorinating agent

Poss, A. J.; Puy, Michael Van Der; Nalewajek, D.; Shia, George A.; Wagner, W. J.; Frenette, Richard

doi:10.1021/jo00020a051

Cited by 60 publications

(17 citation statements)

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“…S15 †) were detected for this ring, which are incompatible with its proposed pyridine N-uorpyridinium heptauorodiborate structure. 39 Its À185.3 ppm 15 N NMR chemical shi better compares to that of N-methylpyridinium iodide (d 15N ¼ À180.5 ppm) 13 and of protonated pyridinium triate (d 15N ¼ À186.5 ppm) than to the chemical shi of free pyridine (d 15N ¼ À67 ppm). 13 These data along with the comparable translational diffusion rates for the two pyridines of 10 (16.9 Â 10 À10 vs. 16.6 Â 10 À10 m 2 s À1 , CD 2 Cl 2 , 25 C) suggest that the nitrogen of this pyridine is quaternalized, likely with a substituent of comparable size to uorine.…”

Section: Nmrmentioning

confidence: 94%

The nature of [N–Cl–N]⁺and [N–F–N]⁺halogen bonds in solution

et al. 2014

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Section: Nmrmentioning

confidence: 94%

The nature of [N–Cl–N]⁺and [N–F–N]⁺halogen bonds in solution

et al. 2014

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“…155 The stereo-and regioselectivity of fluorination of steroids with the reagent 53a have been studied. 115 The reagent 53b was used for stereoselective introduction of fluorine into the a-position relative to the carbonyl group of compound 68. The ratio of enantiomers 69a,b depends on the size of the substituent R. 154 The use of reagents 53a,b is not confined to fluorination reactions; they can also be used in the synthesis of trans-alkenes.…”

Section: The Use Of N-fluoro Sultamsmentioning

confidence: 99%

N-Fluoro amines and their analogues as fluorinating reagents in organic synthesis

Fürin¹,

Fainzil'berg²

1999

Russ. Chem. Rev.

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We show that adiabatic, super-Hubble, and almost scale invariant density fluctuations are produced by cosmic strings in a contracting universe. An essential point is that isocurvature perturbations produced by topological defects such as cosmic strings on super-Hubble scales lead to a source term which seeds the growth of curvature fluctuations on these scales. Once the symmetry has been restored at high temperatures, the isocurvature seeds disappear, and the fluctuations evolve as adiabatic ones in the expanding phase. Thus, cosmic strings may be resurrected as a mechanism for generating the primordial density fluctuations observed today.

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“…The same senior author also introduced 2,3-dihydro-3,3-dimethyl-2-fluoro-1,2-benzisothiazole-1,2-dioxide (11) but its use was limited to reaction with carbanions [19]. N-Fluoropyridinium pyridine heptafluorodiborate (12) [20] and N-fluoro-N-methylp-toluenesulfonate (13) [21] are reagents reported to be useful for fluorination of enol acetates and carbanions, respectively. The low conversions with anisole even at elevated temperatures illustrate the balance between reactivity and selectivity.…”

Section: Resultsmentioning

confidence: 99%