Polyfluoroaromatics

Yakobson, G G, Ed Reactivity of PolyfluoroAromatic Compounds (Russ) Nauka, Sib Otd Novosibirsk, USSR 251... 

Polyfluoroaromatic Monocarbonyl Compounds (Russ) Gerasimova, T N, Fokin, E. P Vsp. Khun. 49, 1057-1078 148... 

Homolytic Arylation of Aromatic and Polyfluoroaromatic Compounds Bolton, R Williams, G H Chem Soc Rev 15, 261-289 122... 

Elemental Huonne as a Legitimate Reagent for Selective Fluonnation of Orgamc Compounds Fluoroaromatic Compounds Synthesis, Reactions, and Commercial Applications New Aspects of Carbonylations Catalyzed by Transition Metal Complexes Polyfluoroaromatics An Excursion m Carbamon Chemistry ... 

Some Peculianties of Radical Reactions of Polyfluoroaromatic Compounds Kobnna, L S J Fluorine Chem 42, 301-344 73 o 5... 

Vibrational Spectra of Polyfluoroaromatic Compounds Korobeimcheva, I K, Fugaeva, O M, Funn, G G J Fluortne Chem 46, 179-209 72 ... 

Kinetics of Nucleophilic Substitution Reactions of Polyfluoroaromatic Compounds Rodionov, P P, Furin, G G J Fluorine Chem 47. 361 34 105 ... 

Magnetic nonequivalence is not uncommon, often deriving from the constraints of a ring, as in pentafluorophenyl derivatives or other symmetrically fluorine substituted ring systems such as those shown in Scheme 2.10. The fluorine and proton NMR spectra of 1,2-difluoroben-zene are both representative of the appearance of second order spectra of polyfluoroaromatics. They can be found in Chapter 3, Section 3.9.3. 

Markovskii, L.N., Furing, G.G., Shermolovich, Y.G., and Yakobson, G.G., Phosphorylation of polyfluoroaromatic compounds. 3. Michaelis-Becker reaction in a series of polyfluoro-substituted benzene derivatives, Izv. Akad. Nauk S.S.S.R., 646, 1981. 

Starichenko and colleagues [185-187] have studied the hydrogenolysis of poly-chloro- and polyfluoroaromatic compounds with the [(NnN)NiCl2]/Zn reducing system (NCN = bpy or phen (phen=l,10-phenanthroline)). Using DMF or DMA... 

TABLE 9. 15N chemical shifts of nitrogen-containing polyfluoroaromatic compounds381... 

Parker and Eberson [17] demonstrated that the oxidation of 9,10-dibromoanthracene in the presence of a nucleophile (e.g. 3,5-lutidine) results in the replacement of a bromine by the nucleophile. In a series of papers [18], various polyfluoroaromatic amines were oxidized at platinum in an acetone-water mixture for example, octafluoroacridone was synthesized from 2-aminononafluorobenzophenone (Scheme 2). 

Polyfluoroaromatic compounds react with xenon difluoride in the presence of Lewis acids to give the products of regiospecific 1,4-addition of fluorine, i.e. the corresponding fluorinated... 

Vanadium(V) fluoride converts polyfluoroaromatics into fluorinated cyclohexadienes and cyclohexenes, and reacts with polyfluorinated and polychlorinated alkenes,113 115 alkadienes, cycloalkenes and cyclodienes to give addition products of two fluorine atoms across C = C bonds.116117... 

Shifts of atoms or groups in fluorine-containing aromatic or heteroaromatic compounds are covered in this section. Shifts due to valence isomerization (benzene-Dewar benzene-prismane-benzvalene), however, are covered in Section 5.3.4.3. A major review1 on polyfluoroaromatic and heteroaromatic compounds has been written by G.M. Brooke, one of the principal contributors in this area, covering the literature until the end of 1995 (see pp 56-59 of ref 1 for the section on rearrangement reactions). 

In addition to the cases of polyfluoroaromatic Claisen rearrangements discussed above, a patent claims an improved preparation of 3-fluorosalicylaldehyde involving the Claisen rearrangement of allyl 2-fluorophenyl ether (Scheme 6).35... 

The reports in 1966 by Haller18 and by Camaggi and co-workers,19 that photolysis of hexafluorobenzene (1) yields the hexafluorinated Dewar benzene isomer 2, triggered intensive in terest in the valence isomers of polyfluoroaromatics and polyfluoroheteroaromatics. 

Zinc can also defluorinate fluorocarbons via a SET pathway. Fluorinated buta-1,2,3-trienes have been stereoselectively defluorinated to divinylalkyne derivatives 6141 and fluorine is eliminated from the CF(CF3)2 group in polyfluoroaromatic compounds.143 The products of the defluorination of perfluoro(l,2,3,4,5,6,7,8-octahydronaphthalene) (7) depend on the polarity of the solvent.142 The higher the polarity of the solvent the more extensive is the defluorination... 

Some Peculiarities of Radical Reactions of Polyfluoroaromatic Compounds ... 

A mechanism postulating formation of a carbocation as an intermediate during oxidative fluorination of the C=C bond was proposed for the reaction of CoF3 with F-benzene and F-pyridine [32], and VF5 with fluoroolefins and polyfluoroaromatic compounds [33] ... 

More data on the reaction of oxidative fluorination of polyfluoroaromatic compounds with halogen fluorides can be found in [86]. 

The reactivity of polyfluorinated cyclohexadienes toward antimony or niobium pentafluorides has some peculiarities. The equilibrium mixture of 1,4- and 1,3-cyclohexadienes is formed from pure isomers of each and a catalytic amount of MF5 at room temperature where the non-conjugated diene predominates [167], With an excess of SbF5 both isomers disproportionate to give a mixture of aromatic compounds and cyclohexene polyfluoroaromatics and the corresponding cyclohexene [167,168] ... 

A second fluorine substituent shields in the ortho- and especially in the para-position, but one in the meta-position deshields, with 1,3-5-trifluorobenzene having the most deshielded fluorines in a polyfluoroaromatic system (Scheme 3.75). On the other hand, hexaflu-orobenzene has highly shielded fluorines. The fluorine spectra of these multifluorobenzenes are second order in nature and their appearance is thus not generally predictable on the basis of first-order logic. 

Fluoroalkenes undergo addition of polyfluoroaromatic compounds in the presence of fluoride ions, c.g. formation of 1. ... 

RpTMS reacts with fluorinated acceptor molecules (A-F) (polyfluoroaromatic compounds. perfluoroalkcnes) to give perfluoroalkylated products and fluorotrimethylsi-lane. ° Periluoroalkylation of hexafluoropropene affords predominantly the ( )-2-cnc product (e.g., 3), but isomerization occurs very easily in the presence of anionic catalysts and the isomeric composition is difficult to control. Moreover, hexafluoropropene undergoes separate dimerization and trimerization processes that result in inefficient use of this component. Nucleophilic addition of periluorooctyl groups via trimethyl(perfluorooctyl)silane to per-lluorocyclopentene involves an addition-elimination mechanism giving perfluoro(l-octylcyclo-pentene) (2). ... 

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