ChemInform Abstract: REACTION OF AROMATIC COMPOUNDS WITH NUCLEOPHILIC REAGENTS IN A LIQUID AMMONIA MEDIUM. IV. NUCLEOPHILIC AND PROTOPHILIC ACTIVITY OF METHYLATE AND HYDROXYL ANIONS IN REACTIONS WITH POLYFLUOROAROMATIC COMPOUNDS

Abstract

Pentafluorbenzol (I) und Hexafluorbenzol (III) werden mit KOH in flüssigem NH3 zu den Polyphenylenpolyfluorderivaten (II) bzw. (IV) umgesetzt.

Selective hydrodechlorination of fluorinated arylamines

“…The 19 F NMR spectral data of 4 and 5 agree with the literature data [25], and those of 6 are identical with the data of the authentic specimen [26]. The 19 F NMR spectral data of compounds are consistent with the literature data: 9 [13].11 [27], 10, 12 [28], 15 and 16 [28,29], 19 [12].…”

Grafting Organic n‐Semiconductors to Surfaces: (Perfluoro‐p‐terphenyl‐4‐yl)alkanethiols

“…In contrast to regular aromatic systems, the typical synthetic entry into this class of substituted perfluoroarenes involves substitution with hard nucleophiles. [10] It therefore seemed favorable to use the known perfluoroarene, perfluoroterphenyl, [5,11] as starting material, since the nucleophilic substitutions preferably take place at the 4-positions of the outer perfluorophenyl rings, which should provide the correctly substituted derivatives. [12] Unfortunately, in our hands, no selective mono-substitution with a carbon nucleophile could be established: With n-butyllithium as a model reagent, even with sub-stoichiometric amounts, up to four alkyl groups were introduced into the perfluoroterphenyl system, with most of the starting material remaining unchanged.…”

“…These difficulties led to the decision to reverse the coupling chemistry and, instead, use the fact that highly fluorinated (but not perfluorinated) arenes are easily metallated due to their relatively high thermodynamic acidity. [13] The respective starting compound, 4Ј-H-tridecafluoroterphenyl (1), can be prepared by the oligomerization of pentafluorobenzene, [5] a procedure that could be successfully scaled up to the 25 g range. The deprotonation of this compound by the action of alkyllithium is accompanied by the statistical alkylation reaction as in the case of perfluoroterphenyl, but this reaction can be controlled to some extent by performing the reaction at a temperature between -80°C and -90°C in diethyl ether (in THF the formation of an insoluble byproduct dominates).…”

“…[4] In contrast to the relatively demanding syntheses of the perfluoroacenes, the access to the perfluorooligophenyls is much less complicated. [5] Nevertheless, the reports [4,5] give only the syntheses of the parent compounds: Neither their structural properties nor the directed syntheses of functional derivatives have been described yet. In our effort to study ultra-thin films of organic semiconductors, we considered it of interest to (1) synthesize such functionalized perfluoro-oligophenyl derivatives, (2) determine their molecular structure, and (3) deposit them onto surfaces.…”

Amination of octafluoronaphthalene in liquid ammonia

“…Nucleophilic substitution in b-X-heptafluoronaphthalenes or insertion of two substituents into 1 results in the mixture of b,bdisubstituted isomers with the 2,6 being predominant (>75%) [3][4][5][6][7][8]. Only some of the individual 2,6-disubstituted hexafluoronaphthalenes have been reported (2-methoxy-6-thiomethoxyhexafluoronaphthalene [3], 2-methoxy-6-piperidinohexafluoronaphthalene [4], 1,3,4,5,7,8-hexafluoronaphthalene [5], perfluoro-2,6-diphenylnaphthalene [6]), while 2,7-isomers have not been isolated at all. Diamination of 1 has not been reported, though polyfluoroaromatic diamines and diaminohexafluoronaphthalenes in particular are prospective monomers for condensation polymers, whose physicochemical characteristics depend strongly on the framework as well as presence of fluorine atoms [9].…”