127723-77-7Relevant academic research and scientific papers
Phosphonium ionic liquids as highly thermal stable and efficient phase transfer catalysts for solid-liquid Halex reactions
Fan, Ao,Chuah, Gaik-Khuan,Jaenicke, Stephan
, p. 300 - 304 (2012)
Trihexyl (tetradecyl) phosphonium tetrafluoroborate was found to be an active catalyst for the introduction of fluoride by nucleophilic aromatic substitution. With a decomposition temperature above 300 °C, this ionic liquid is suitable for reactions at high temperatures. The addition of 1 mol% of the ionic liquid relative to KF increased the initial rate for the fluorination of 1,2-dichloro-4-nitrobenzene six-fold compared to the uncatalysed reaction. The highest reaction rate was observed at 20 mol% ionic liquid relative to KF. Ease of handling without the need for stringent drying conditions and reuseability make this ionic liquid a useful phase transfer catalyst.
THE REACTION OF FLUOROXYSULFATE, SO4F(1-), WITH AROMATIC COMPOUNDS: CATLYSIS BY ACIDS
Appelman, Evan H.,Basile, Louis J.,Hayatsu, Ryoichi
, p. 189 - 198 (1984)
The effects of the acid catalysts HF, H2SO4, BF3, CF3SO3H, FSO3H, and SbF5*FSO3H on the reactions of CsSO4F with toluene, nitrobenzene and naphthalene in CH3CN have been studied.The catalysts in general accelerate reaction and enhance yields of ring-fluorinated products.Efficacity roughly parallels H0 of the acids, though H2SO4 is more effective than stronger acids for fluorination of naphthalene.Combined room temperature yields of fluorine-substituted products are as much as 45-50 percent for toluene and naphthalene and up to 30 percent for nitrobenzene.The predominant products are o-fluorotoluene, 1-fluoronaphthalene, and m-fluoronitrobenzene.With naphthalene the isomer selectivity is considerably less than in the absence of catalyst.Low yields ( = 10 percent) of monomeric oxygenated products are obtained, along with considerable oxygen- and fluorine-containing dimers and higher polymers.The results are interpreted in terms of acid-catalyzed electrophilic fluorination or oxygenation, followed by further fluorination and/or freeradical-induced oxidative coupling of the oxygenated products.
Vastly Improved Para Preference in the Nitration of Halobenzenes
Laszlo, Pierre,Pennetreau, Pascal
, p. 2407 - 2410 (1987)
The halobenzenes are monitrated with cupric nitrate supported on the K10 montmorillonite in the presence of acetic anhydride, in hexane, or in the methylene chloride, at room temperature or below.Good isolated yields (50-75percent) are accompanied by much improved para selectivities, up to a para-to-ortho ratio of 35 (a selectivity factor of 70) for fluorobenzene.The observed selectivity factors are determined uniquely by the polarizability of the halogen substituent.
SUBSTITUTION AND ADDITION REACTIONS OF NF4BF4 WITH AROMATIC COMPOUNDS
Schack, Carl J.,Christe, Karl O.
, p. 363 - 374 (1981)
Benzene, toluene, and nitrobenzene interact rapidly with NF4BF4 in anhydrous HF to give, almost exclusively, fluorine substituted aromatic derivatives.Up to four hydrogens can be replaced in a rapid reaction, before a much slower addition reaction takes over.The direction of the substitution in C6H6, C6H5CH3 and C6H5NO2 and the lack of side chain fluorination in C6H5CH3 support an electrophilic substitution mechanism.These rapid substitution reactions are followed by much slower fluorine addition reactions to give the corresponding cyclo-hexadienes and -hexenes.These addition reactions were also studied separately using tetra-, penta-, and hexa- fluorobenzene as the starting materials.In these addition reactions, almost no hydrogen substitution occurred.The addition of the first pair of fluorines always gave 1,4-cyclohexadienes in which the CF2 group was adjacent to hydrogen on the ring.The addition of the second pair of fluorines resulted in the formation of cyclohexenes.These reactions occured in high yield and offer a controlled, high yield path to dienes.All products were characterized spectroscopically and by comparison to literature data.
An improved method for fluoro-dediazoniation of arylamines substituted with polar groups
Sasaki, Koshi,Oishi, Mari,Imaki, Naoshi
, p. 59 - 62 (1996)
The addition of SnX2 (SnCl2 or SnF2), as a low redox potential reductant, at the fluoro-dediazoniation step in the deaminative fluorination of aryl amines substituted with polar groups gave high selectivities for the formation of fluoroaromatics under mild conditions. The selectivities were further increased by the addition of a nucleophilic fluoride anion source, i.e. tetrabutylammonium dihydrogen trifluoride nBu4N+ H2F3-, along with the reductants.
A polymer onium acting as phase-transfer catalyst in halogen-exchange fluorination promoted by microwave
Luo, Jun,Lü, Chunxu,Cai, Chun,Qü, Wenchao
, p. 701 - 704 (2004)
A polymerized quaternary ammonium salt polydiallyldimethylammonium chloride, exhibiting high stability to heat and base, was prepared and applied as phase-transfer catalyst (PTC) in halogen-exchange (Halex) fluorination of chloronitrobenzenes to give excellent yields of corresponding fluoronitrobenzenes. Dimethyl sulfoxide was found to be the best solvent when microwave was applied as heating resource.
1-Fluoro-2,4,6-trichloro-1,3,5-triazinium tetrafluoroborate: Synthesis, characterization, and ability to effect electrophilic aromatic substitution
Banks, R. Eric,Besheesh, Mohamed K.,Fraenk, Wolfgang,Klap?tke, Thomas M.
, p. 229 - 232 (2003)
The synthesis of 1-fluoro-2,4,6-trichloro-1,3,5-triazinium tetrafluoroborate, [(ClCN)3F]+[BF4] - (1), from (ClCN)3, BF3 and F2 is reported. Compound 1 was shown to be a useful reagent for the quantitative fluorination of aromatic substrates such as benzene, chlorobenzene, nitrobenzene, and methoxybenzene.
A polymer imidazole salt as phase-transfer catalyst in halex fluorination irradiated by microwave
Liang, Zheng Yong,Lü, Chun Xu,Luo, Jun,Dong, Li Bin
, p. 608 - 611 (2007)
A new imidazole polymer salt was synthesized in order to develop a high efficiency phase-transfer catalyst for multi-phase reactions. The polymer salt was prepared easily by co-polymerization of 1-1′-(1,4-butamethylene)bis(imidazole) and 1,2-dibromoethane, and has the properties of excellent chemical and thermal stability and high ionic conductivity. It was applied as phase-transfer catalyst in the fluorination of chloronitrobenzenes under the irradiation of microwave and gave excellent yields of corresponding fluoronitrobenzenes. In addition, the enhanced mechanism of microwave was studied and found "non-thermal" effect was a great factor.
INTERACTION OF CHLOROAROMATIC COMPOUNDS WITH ALKALI METAL FLUORIDES IN THE PRESENCE OF CROWN-ETHERS
Aksenov, V.V.,Vlasov, V.M.,Moryakina, I.M.,Rodionov, P.P.,Fadeeva, V.P.,et al.
, p. 73 - 88 (1985)
The influence of various crown-ethers on the reactions of polychloroaromatic compounds with alkali metal fluorides (KF, RbF, CsF) has been studied.It is shown that the catalytic effect of the crown-ether is almost independent of the nature of the polychloroaromatic substrate and that it is most effective only in a definite range of reaction rates.
FLUORODENITRATIONS USING TETRABUTYLAMMONIUM FLUORIDE
Clark, James H.,Smith, David K.
, p. 2233 - 2236 (1985)
Fluoroaromatics are prepared in good yield under mild conditions using the tetrabutylammonium fluoride promoted fluorodenitration of nitroaromatics.
