572. Aromatic polyfluoro-compounds. Part XVIII. Some replacement reactions of perfluoro-o- and -p-xylene

Aroskar, E. V.; Chaudhry, M. T.; Stephens, R.; Tatlow, J. C.

doi:10.1039/jr9640002975

Cited by 12 publications

(3 citation statements)

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“…As a weaker donor, the methoxy substituent of 1b appears to inhibit its reaction with a second equivalent of methoxide, but its influence is not sufficiently strong to prevent substitution of the other, unsubstituted benzene ring of 1b . The observed result was consistent with results obtained by Tatlow and co-workers in their study of the reaction of perfluoro- p -xylene with methoxide ion . In contrast, the results obtained from the reaction of F8 with thiophenolate anion clearly indicate that the SPh substituent of the putative monoadduct must activate that ring toward addition of a second nucleophile.…”

Section: Resultssupporting

confidence: 91%

“…Because of the presence of multiple fluorine substituents, hexafluorobenzene and pentafluoropyridine exhibit high reactivity toward nucleophiles (Scheme ), ,,, as do trifluoromethyl-substituted analogues, such as perfluorotoluene. ,, In a kinetic study of the reactivity of perfluoropolymethylbenzenes toward nucleophiles, it was observed that, in its reaction with − OCH 3 /HOCH 3 at 25 °C, perfluorotoluene is 7000 times as reactive as hexafluorobenzene. Adding a second (para) trifluoromethyl group (as in perfluoro- p -xylene) leads to a somewhat lower reactivity, but it is still 2900 times more reactive than hexafluorobenzene.…”

Section: Introductionmentioning

confidence: 99%

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Reactions of Nucleophiles with Perfluoro[2.2]paracyclophane

et al. 2009

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The aromatic rings of perfluoro[2.2]paracyclophane are extremely reactive with respect to nucleophilic substitution reactions. This paper emphasizes products of monosubstitution by hydroxide, alkoxide, thiolate, enolate, and amine nucleophiles. All reactions appear to proceed via S(N)Ar mechanisms; reactivity issues are discussed including the effect of substituents on reactivity and regiochemistry of substitution.

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Section: Resultssupporting

confidence: 91%

Section: Introductionmentioning

confidence: 99%

Reactions of Nucleophiles with Perfluoro[2.2]paracyclophane

et al. 2009

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“…17 Thus amination of о and p perfluoroxylenes with NH 3 in aqueous alcohol at 150 °C affords monoamino derivative in a moderate yield (~40-50%), which is caused, in particular, by com plexity of product isolation (preparative GLC) from multi component mixtures. No data on amination of per fluoroxylene 7a were found, although one paper 18 pre sents the 19 F NMR spectrum of 3,5,6 trifluoro 2,4 bis(tri fluoromethyl)aniline (7b).…”

Section: Methodsmentioning

confidence: 98%

Selective mono-and diamination of polyfluorinated benzenes and pyridines with liquid ammonia

et al. 2007

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Amination of pentafluoropyridine, 2,3,5,6 tetrafluoropyridine, 4 chlorotetrafluoropyridine, 3,5 dichlorotrifluoropyridine, octafluorotoluene, α,α,α,2,3,5,6 heptafluorotoluene, deca fluoro m xylene, decafluorobiphenyl, hexafluorobenzene, and pentafluorobenzene with liquid ammonia was investigated. Bis aminodefluorination temperatures for the majority of sub strates were shown to exceed significantly the corresponding temperatures of monoamino defluorination. The optimal conditions for selective preparation of mono and diamino polyfluoro(het)arenes were elucidated. An efficient method for isolation of particular polyfluorophenylenediamines from product mixtures formed in nonselective reactions of pentafluorobenzene and hexafluorobenzene with aqueous ammonia based on complexation with a crown ether is proposed. N. N. Vorozhtsov´s school made a considerable con tribution to the chemistry of polyfluoroaromatic com pounds: methods for the synthesis 1 and functionali zation 2,3a of base polyfluoroarenes were developed. Cur rently many polyfluoroarene derivatives are demanded for high tech processes and materials. In particular, diamino and dihydroxy(poly)fluoroarenes serve as struc tural blocks in the synthesis of polyimides used in fiber optic and thin film light guides, nanofilters, and mem branes, dielectric coatings, liquid crystalline displays, op tical diodes, laser media, etc. 4 Polyfluorinated amines of the benzene and pyridine series are used in the synthesis of biologically active compounds. 5It is known 6 that aminodehalogenation of arenes in aqueous ammonia, which is usually carried out in steel autoclaves at high temperatures (up to 250 °C), is often accompanied by competing transformations of arenes such as hydroxy and/or hydrodehalogenation involving water and the autoclave material. The version of the method of polyfluoroarene amination developed in this study im plies the use of liquid ammonia as both the reagent and the reaction medium. The possibility of aminodefluorina tion of some polyfluoroarenes with enhanced electrophi licity in liquid ammonia has been demonstrated previ ously. 7 The efficiency of liquid ammonia as a medium for aromatic nucleophilic substitution has been described in a review. 8 Note that the temperatures suitable for the work with liquid ammonia are limited by the range from -70 to 120 °C (m.p. -78 °C, critical point 133 °C). 9 It follows from analysis of published data that arene amino dehalogenation in liquid ammonia has a higher rate than that in aqueous ammonia; therefore, the processes are carried out at relatively low temperatures and the side reactions are minimized.The purpose of this study was to elucidate the condi tions for mono and diamination of polyfluorinated ben zene and pyridine derivatives in liquid ammonia, which are optimal as regards the selectivity and product yield, to develop simple and practically feasible techniques for separation of mixtures of amino compounds, and to syn thesize new high purity polyfluoroaromatic diamines de manded in high tech applic...

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Poly(P‐phenylene sulfide) hexafluoroarsenate: A novel conducting polymer

Clarke

Kanazawa

Lee

et al. 1982

J. Polym. Sci. Polym. Phys. Ed.

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Poly(p‐phenylene sulfide) (PPS) is a melt‐ and solution‐processible polymer which on treatment with AsF5 forms a blue‐black material with a conductivity of 1–10 Ω−1 cm−1. Thermopower measurements indicate that the resulting polymer is p type, consistent with partial oxidation of the PPS by the AsF5. The rate and extent of this doping process prove to be particularly sensitive to the degree of crystallinity of the starting polymer. There is also evidence of crosslinking of the polymer chains during the reaction with AsF5. The details of both the chemistry and physics of the doping of PPS and several of its derivatives are presented.

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572. Aromatic polyfluoro-compounds. Part XVIII. Some replacement reactions of perfluoro-o- and -p-xylene

Cited by 12 publications

References 0 publications

Reactions of Nucleophiles with Perfluoro[2.2]paracyclophane

Reactions of Nucleophiles with Perfluoro[2.2]paracyclophane

Selective mono-and diamination of polyfluorinated benzenes and pyridines with liquid ammonia

Poly(P‐phenylene sulfide) hexafluoroarsenate: A novel conducting polymer

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