Fluorinated aryl azides

Schnapp, K.A., Poe, R., Leyva, E., Soundararajan, N., and Platz, M.S. (1993) Exploratory photochemistry of fluorinated aryl azides. Implications for the design of photoaffinity labeling reagents. Bioconjugate Chem. 4, 172-177. 

Laser flash photolysis of a series of fluorinated aryl azides produces the transient spectra of the corresponding singlet nitrenes. ° With the exception of singlet o-fiuorophenylnitrene (39s), the rate of decay of the singlet nitrene was equal to the rate of formation of the reaction products, for example, didehydroazepines and triplet nitrenes. Values of fejsc and the Arrhenius parameters for azirine formation are summarized in Table 11.5. 

Pentafluorophenyl azide was first synthesized by Haszeldine et al. in 1962 [92]. Ten years later, Banks and Sparkes [93] began to study the chemistry of polyfiuorinated aryl nitrenes generated by thermolysis of fluorinated aryl azides. 

Particular attention has been devoted this year to the study of fluorinated aryl azides. This interest stems from their potential use as photoaffinity probes due to the ease with which perfluorophenyl nitrene undergoes C-H bond insertion. Perfluorin-ated azide derivatives of methyl benzoate afford photochemically... 

Thermal decomposition of aryl azides under a nitrogen atmosphere leads to nitrenes which are able to substitute fluorine in polyfluorinated naphthalenes, albeit with a poor yield (4%). Since no substitution product was isolated when oxygen was present during this reaction, the intermediacy of a triplet nitrene was proposed, which is completely trapped by oxygen.207... 

Aziridine formadon from arylnitrenes, rather than via tiiazolines, is known for highly fluorinated arenes. Phenyl azide with trifluotoacetic acid generates a nitrenium ion which adds stereospecifically to alkenes to give aziridines. Yields are rather low, pardy due to concurrent ring opening of the aziridine by addidon of trifluoroacedc acid. Similar reacdons can be adiieved with Lewis acids such as AlCb. Enamines with aryl azides can yield either 2-aminoaziridines or amidines. ... 

Recent progress on the use of hypervalent iodine reagents for the construction of carbon-het-eroatom (N, O, P, S, Se, Te, X) bonds is reviewed. Reactions of aryl-A3-iodanes with organic substrates are considered first and are loosely organized by functional group, separate sections being devoted to carbon-azide and carbon-fluorine bond formation. Arylations and alkenyla-tions of nucleophilic species with diaryliodonium and alkenyl(aryl)iodonium salts, and a variety of transformations of alkynyl(aryl)iodonium salts with heteroatom nucleophiles are then detailed. Finally, the use of sulfonyliminoiodanes as aziridination and amidation reagents, and reactions of iodonium enolates formally derived from monoketones are summarized. 

These compounds contain the characteristic group -N=S(0)X- (where X = Cl, F, alkyl, aryl, or R2N). Unlike the isoelectronic cyclophosphazenes, only six-membered rings have been well characterized. The sulfanuric halides are colorless solids (X = Cl) or liquids (X = F), which are stable in dry air. Sulfanuric chloride is best prepared by treatment of SOCI2 with sodium azide (equation 26). It may also be obtained as a mixture of a- and /3-isomers in a two-stage reaction from H2NSO3H and PCI5. The fluoride, [NS(0)F]3, is formed as a mixture of isomers by the fluorination of [NS(0)C1]3 with SbF3. 

Peng W, Zhu S-Z (2002) 1,3-Dipolar cycloaddition of P-alkoxyvinyl trifluoromethylketones with aryl (or benzyl) azides. Synthesis of 4-trifluoroacetylated IH-1,2,3-triazoles. J Fluorine Chem 116 81-86... 

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