41481-22-5Relevant academic research and scientific papers
Extremely facile ring inversion and rearrangement in fluorobicyclo[2.1.0]pentanes
Wei, Yanjun,Liu, Yufa,Wong, Terrence,Lemal, David M.
, p. 688 - 703 (2008/09/16)
cis-1,2,3,4,5,5-Hexafluorobicyclo[2.1.0]pentane and 1,2,4,5-tetrafluorobicyclo[2.1.0]pentane have been synthesized from hexafluorobenzene. The former hydrofluorocarbon, which exists entirely in the endo configuration, rearranges to cis-1,2,3,3,4,5-hexafluorocyclopentene below room temperature (Ea = 21.9 kcal/mol, log A = 13.4). The latter undergoes degenerate ring inversion with extraordinary ease (ΔG? = 6.8 ± 0.2 kcal/mol at -55 °C). Density functional calculations indicate that significant bonding between the bridgehead carbons is retained in the ring inversion transition state. Analogous calculations predict for hexafluorobicyclo[1.1.0]butane a considerably lower barrier for ring inversion and more 1,3-bonding in the transition state.
Electrophilic oxygenation with XeF2 - H2O in hydrogen fluoride, Part 2. Electrophilic oxygenation of pentafluorobenzene derivatives C6F5X
Frohn,Bardin
, p. 1015 - 1021 (2007/10/03)
Electrophilic oxygenation of polyfluorobenzenes C6F5X (X = F, Cl, Br, H, CF3, NH3+, NMe3+, OH and OCH2CF3) with XeF2 and H2O in HF leads to the formation of polyfluorinated 1,4-cyclohexadienones. Pentafluoroiodobenzene is converted into C6F5IF2 and C6F5IF4, whereas [C6F5N2]+ [NbF6]- is unreactive towards this new type of electrophilic oxygenation.
REACTION OF POLYFLUORINATED DERIVATIVES OF BENZENE CONTAINING HYDROGEN ATOMS IN THE SIDE CHAIN WITH VANADIUM PENTAFLUORIDE
Avramenko, A. A.,Bardin, V. V.,Karelin, A. I.,Krasil'nikov, V. A.,Tushin, P. P.,et al.
, p. 2318 - 2323 (2007/10/02)
The treatment of C6F5R (R=CH3, CH2F, CHF2) compounds with vanadium pentafluoride at -25 to -30 deg C leads to a 1-R-heptafluoro-1,4-cyclohexadienes, 1-R-nonafluorocyclohexenes, and products form fluorination of the side chain.Fluorination of the anisole derivatives C6F5OCH3 and C6F5OCHF2 only takes place in the aromatic ring.
New Routes to Hexafluorocyclopentadiene and Related Compounds
Soelch, Richard R.,Mauer, George W.,Lemal, David M.
, p. 5845 - 5852 (2007/10/02)
Hexafluorocyclopentadiene (1) has been synthesized in two steps from pentafluorophenol (2) by fluorination followed by flash vacuum pyrolysis of the resulting hexafluorocyclohexadienones 3 and 4.Similar pyrolysis of 6-chloropentafluorocyclohexadienone (13) gave an equilibrium mixture of 1- and 2-chloropentafluorocyclopentadiene (15 and 16), presumably via the 5-chloro isomer.Flash vacuum pyrolysis of tetrafluoro-o-benzoquinone 17 yielded tetrafluorocyclopentadienone (20).Hexafluorocyclopentadiene was also prepared via a ring-expansion route which entailed cycloaddition (accompanied by rearrangement) of bromotrifluoroethylene to tetrafluorocyclopropene followed by reductive debromofluorination.
AROMATIC FLUORINE DERIVATIVES. C. REACTIONS OF PENTAFLUOROPHENOL WITH VANADIUM, NIOBIUM, AND ANTIMONY FLUORIDES AND XENON DIFLUORIDE
Avramenko, A. A.,Bardin, V. V.,Karelin, A. I.,Krasil'nikov, V. A.,Tushin, P. P.,et. all
, p. 746 - 749 (2007/10/02)
Pentafluorophenol reacts with vanadium fluorides and xenon difluoride giving perfluoro-2,5-cyclohexadien-1-one and the products from dimerization of the pentafluorophenoxyl radical, i.e., perfluoro-6-phenoxy-2,4-cyclohexadien-1-one, perfluoro-4-phenoxy-2,5-cyclohexadien-1-one, and perfluoro-2-phenoxy-2,5-cyclohexadien-1-one.Antimony and niobium pentafluorides give stable complexes or the corresponding pentafluorophenolates with pentafluorophenol.
INTERACTION OF PENTAFLUOROPHENOL WITH LEAD TETRAACETATE IN ACIDS
Kovtonyuk, V.N.,Kobrina, L.S.,Yakobson, G.G.
, p. 89 - 98 (2007/10/02)
The ability of polyfluorinated hydroxyaromatic compounds to be oxidised by radical and ionic mechanisms is discussed.Oxidation of pentafluorophenol by lead tetraacetate in hydrogen fluoride and trifluoroacetic acid gave the products of a reaction proceeding by an ionic mechanism - hexafluorocyclohexa-2,5-dienone and trifluoroacetoxydienones respectively.
BF3-Catalyzed Fluorine Addition to Fluoro-Substituted Benzene Derivatives Using Xenon Difluoride
Stavber, Stojan,Zupan, Marko
, p. 300 - 302 (2007/10/02)
BF3-catalyzed room-temperature reaction of xenon difluoride with pentafluoro-substituted benzene derivatives resulted in 1,4- and 1,2-fluorine addition with regiospecificity depending on the substituent.Reaction with 1-substituted (H, Cl, Br, C6F5) pentafluorobenzene resulted in the formation of 1-substituted heptafluorocyclohexa-1,4-dienes, and reactions with n-alkoxy-substituted pentafluorobenzenes resulted in two types of 1,4-adducts, while reaction with isopropoxypentafluorobenzene resulted in the formation of hexafluorocyclohexa-2,5-dien-1-one and hexafluorocyclohexa-2,4-dien-1-one.
AROMATIC FLUORINE DERIVATIVES. XCI. REGIOSPECIFIC FLUORINATION OF POLYFLUORINATED AROMATIC COMPOUNDS BY SALTS OF THE DIFLUOROBROMONIUM CATION BrF2+
Bardin, V. V.,Furin G. G.,Yakobson, G. G.
, p. 879 - 884 (2007/10/02)
The reaction of polyfluorinated aromatic compounds with difluorobromium tetrafluoroborate BrF2+*BF4- leads to the products from regiospecific fluorination.Polyfluorinated derivatives of benzene, toluene, and naphthalene are fluorinated to form 1,4-cyclohexadienes, whereas pentafluoropyridine and 3-chlorotetrafluoropyridine are converted into the corresponding 1-aza-1,3-cyclohexadienes.
