N-Halogeno compounds Part 191: Electrophilic fluorinating agents of the multiple mono-N-fluoro class derived from nitrogen heterocycles

Banks, R. E.; Besheesh, Mohamed K.; Mohialdin-Khaffaf, Suad N.; Sharif, Iqbal

doi:10.1016/s0022-1139(96)03521-x

Cited by 15 publications

(8 citation statements)

References 11 publications

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“…The ortho/para ratios obtained in the fluorination of phenol with NFSI were similar (or even equal) to those observed in the fluorination of the same substrate with other N-F reagents in various solvents, e.g., with bis-(4-fluoro-1,4-diazoniabicyclo[2.2.2]oct-1-yl)propane tetrakis(trifluoromethanesulfonate) in methanol (~1.5) [28], N,N′-difluoro-2,2′-bipyridinium bis(tetrafluoroborate) in acetonitrile (1.2) [29], and 1-fluoro-4-methyl-1,4-diazoniabicyclo[2.2.2]octane bis(trifluoromethanesulfonate) in methanol (~1.5) [30].…”

Section: Fluorination Of Aromatic Compounds With N-fluorobenzenesulfosupporting

confidence: 71%

Fluorination of aromatic compounds with N-fluorobenzenesulfonimide under solvent-free conditions

2009

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Reactions of N-fluorobenzenesulfonimide with methylbenzenes, phenols, and phenol ethers were studied under solvent-free conditions. The rate constant ratio for the reactions with mesitylene and durene indicates polar mechanism of the process. Solvent-free fluorination of aromatic compounds with N-fluorobenzenesulfonimide in some cases is more selective than reactions with other N-F reagents in a solvent.Fluorinated aromatic compounds are widely used as pesticides, medicinal agents, and various functional materials; therefore, development of ecologically friendly and selective fluorination procedures seems to be an important problem [1][2][3]. During the past two decades, N-F reagents [1-17] have been extensively used as source of fluorine in mild and selective fluorination of organic compounds. In particular, such reagent is N-fluorobenzenesulfonimide (NFSI) [2,4,[7][8][9][18][19][20][21][22][23][24]. It is nonhygroscopic, stable to storage, and convenient to handle with. N-Fluorobenzenesulfonimide is quite reactive, but at the same time it exhibits a moderate oxidative ability [2], which is important for fluorination of organic compounds with low oxidation potentials. N-Fluorobenzenesulfonimide is commonly used to effect fluorination of carbanions, enolates, and enol ethers in the synthesis of fluorinated intermediate products necessary for the manufacture of medicinal agents [7][8][9]. Direct fluorination of aromatic compounds with NFSI was performed less frequently than with other N-F reagents, e.g., 1-chloromethyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane salts .The goal of the present work was to study the selectivity in fluorination of aromatic compounds, namely methyl-substituted benzenes, phenols, and phenol ethers, with NFSI in the absence of a solvent. The selectivity problem in electrophilic fluorination under these conditions remains poorly studied (cf. [22]).We have found that the yield of monofluoro derivatives in the fluorination of polymethylbenzenes

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Section: Fluorination Of Aromatic Compounds With N-fluorobenzenesulfosupporting

confidence: 71%

Fluorination of aromatic compounds with N-fluorobenzenesulfonimide under solvent-free conditions

2009

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“…140 Some N-fluorinating reagents, e.g., N,N H -difluoro-2,2 H -bipyridinium (55b) and N-methyl-N H -fluoro-4,4 H -bipyridinium (58) bistriflates and N,N H -difluoro-2,2 H -bipyridinium (57a) bistetrafluoroborate, proved to be very convenient reagents for fluorination of various types of organic compounds (Tables 12 and 13). 142,143 The introduction of readily polymerisable groups into the pyridine ring of the reagents 55 ± 57 allows one to obtain polymers with molecular masses above 500 000 Daltons. The latter are used as electrolytes (i.e., as an active cathode mass) in batteries and as solid fluorinating agents.…”

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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“…They described this as a “transfer fluorination” since there was an intermolecular transfer of the fluorine atom of Selectfluor to the nitrogen of quinuclidine. In 1996, full details were published on the reactivities of all 16-3 reagents and the syntheses of 16-3 and intermediates 16-2 including additionally C 2 H 5 and C 8 H 17 as R group and PF 6 − and FSO 3 − as anion X − [ 63 – 64 ].…”

Section: Reviewmentioning

confidence: 99%

“…In 1997, the Banks group reported bis- N -fluoro reagents 23-1 – 3 and related salts 23-4 , 5 by the fluorination of precursors containing two heterocycles ( Scheme 51 ) [ 85 ]. Reagents 23-1–3 and -5 were obtained in good yields and 23-4 was also obtained, but as an impure product.…”

Section: Reviewmentioning

confidence: 99%

Development of N-F fluorinating agents and their fluorinations: Historical perspective

Umemoto¹,

Yang²,

Hammond³

2021

Beilstein J. Org. Chem.

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This review deals with the historical development of all N-F fluorinating agents developed so far. The unique properties of fluorine make fluorinated organic compounds attractive in many research areas and therefore fluorinating agents are important. N-F agents have proven useful by virtue of their easy handling. This reagent class includes many types of N-F compounds: perfluoro-N-fluoropiperidine, N-fluoro-2-pyridone, N-fluoro-N-alkylarenesulfonamides, N-fluoropyridinium salts and derivatives, N-fluoroquinuclidium salts, N-fluoro-trifluoromethanesulfonimide, N-fluoro-sultams, N-fluoro-benzothiazole dioxides, N-fluoro-lactams, N-fluoro-o-benzenedisulfonimide, N-fluoro-benzenesulfonimide, 1-alkyl-4-fluoro-1,4-diazoniabicyclo[2.2.2]octane salts, N-fluoropyridinium-2-sulfonate derivatives, 1-fluoro-4-hydroxy-1,4-diazoniabicyclo[2.2.2]octane salts, N-fluorodinitroimidazole, N-fluoro-trichloro-1,3,5-triazinium salt, N-F ethano-Tröger’s base derivatives, N-fluoro-methanesulfonimide, N-fluoro-N-arylarenesulfonamides, bisN-F salts such as N,N’-difluorobipyridinium salts and N,N’-difluoro-1,4-diazoniabicyclo[2.2.2]octane salts, and their many derivatives and analogs, including chiral N-F reagents such as optically active N-fluoro-sultam derivatives, N-fluoro-alkaloid derivatives, DABCO-based N-F derivatives, and N-F binaphthyldisulfonimides. The synthesis and reactions of these reagents are described chronologically and the review also discusses the relative fluorination power of each reagent and their mechanisms chronicling developments from a historical perspective.

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N-Halogeno compounds Part 191: Electrophilic fluorinating agents of the multiple mono-N-fluoro class derived from nitrogen heterocycles

Cited by 15 publications

References 11 publications

Fluorination of aromatic compounds with N-fluorobenzenesulfonimide under solvent-free conditions

Fluorination of aromatic compounds with N-fluorobenzenesulfonimide under solvent-free conditions

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

Development of N-F fluorinating agents and their fluorinations: Historical perspective

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