363-72-4Relevant articles and documents
Deacon, G. B.,Parrott, J. C.
, p. 11 - 23 (1968)
The fluorine-pentafluorophenyl substitution reaction in anhydrous hydrogen fluoride (aHF): A new interesting methodical approach to synthesize pentafluorophenylxenonium salts
Frohn, Hermann-Josef,Schroer, Thorsten
, p. 259 - 264 (2001)
In anhydrous hydrogen fluoride (aHF) (heterogeneous reaction) B(C6F5)3 transfers all the three aryl groups to XeF2 forming [C6F5Xe]+ salts. Upon addition of KF, the [C6F5Xe] [HF2] salt was isolated in 78.7% yield. [C6F5Xe] [HF2] dissolved in MeCN exhibits significant cation-anion interactions and decomposes within 14 days at 20°C. The acidity of the aHF solvent determines the nature of the products in the reaction of XeF2 with B(C6F5)3. The reaction path of this new methodical approach of fluorine-aryl substitution in aHF is discussed.
Promotion of reductive elimination reaction of diorgano(2,2′-bipyridyl)nickel(II) complexes by electron-accepting aromatic compounds, Lewis acids, and Bronsted acids
Yamamoto, Takakazu,Abla, Mahmut,Murakami, Yasuharu
, p. 1997 - 2009 (2002)
Reductive elimination of R-R from dialkyl(2,2′-bipyridyl)nickel(II), [NiR2(bpy)] 1 (R = CH3 (1a), C2H5 (1b), n- C3H7 (1c)), caused by π-coordination of electron-accepting aromatic compounds and reductive elimination of Ar-Ar from [NiAr2(bpy)] 2 (Ar = C6F5 (2a) and pyrazolyls (2b and 2c)) promoted by electron-accepting aromatic compounds, Lewis acids, and Bronsted acids have been investigated. 1H-NMR and kinetic data indicate that π-coordination of the electron-accepting aromatic compound to [NiR2(bpy)] leads to the reductive elimination of R-R. The rate of the reductive elimination obeys the second-order rate law, -d[1]/dt = k[1][electron-accepting aromatic compound]. Plots of log k vs Σσp of the electron-accepting aromatic compound give a line with a slope of 1.8. Bronsted acids cause reductive elimination of Ar-Ar from 2 selectively under several reaction conditions (e.g., 2a with CF3COOH in air and 2b with HBr). The reductive elimination reaction of 2a caused by CF3COOH obeys the second-order rate law, -d[2a]/dt = k′[2a][CF3COOH], in air. The reaction of 2b with H2SO4 requires O2, giving the rate equation, -d[2b]/dt = k″[2b]2[O2]; k″ increases with [H2SO4], reaching a maximum value at a high [H2SO4]. UV-vis spectroscopy reveals the presence of the following equilibrium: 2b + H2SO4 ? 2b·H2SO4, and the equilibrium constant Ka is evaluated as Ka = [2b·H2SO4]/ ([2b][H2SO4]) = 47 M-1 at 300.5 K. UV-vis data give information about the electronic states of 2 and the 2b-Bronsted acid adduct. Poly(6-hexylpyridine-2,5-diyl) with a higher molecular weight has been prepared according to the basic information.
Promoting Difficult Carbon–Carbon Couplings: Which Ligand Does Best?
Gioria, Estefanía,del Pozo, Juan,Martínez-Ilarduya, Jesús M.,Espinet, Pablo
, p. 13276 - 13280 (2016)
A Pd complex, cis-[Pd(C6F5)2(THF)2] (1), is proposed as a useful touchstone for direct and simple experimental measurement of the relative ability of ancillary ligands to induce C?C coupling. Interestingly, 1 is also a good alternative to other precatalysts used to produce Pd0L. Complex 1 ranks the coupling ability of some popular ligands in the order PtBu3>o-TolPEWO-F≈tBuXPhos>P(C6F5)3≈PhPEWO-F>P(o-Tol)3≈THF≈tBuBrettPhos?Xantphos≈PhPEWO-H?PPh3according to their initial coupling rates, whereas their efficiency, depending on competitive hydrolysis, is ranked tBuXPhos≈PtBu3≈o-TolPEWO-F>PhPEWO-F>P(C6F5)3?tBuBrettPhos>THF≈P(o-Tol)3>Xantphos>PhPEWO-H?PPh3. This “meter” also detects some other possible virtues or complications of ligands such as tBuXPhos or tBuBrettPhos.
Reaction of difluoromethyl pentafluorophenyl sulfoxide with nucleophiles
Koshcheev,Maksimov,Platonov,Shelkovnikov
, (2017)
Reactions of 1-(difluoromethanesulfinyl)pentafluorobenzene with sodium methoxide, sodium phenoxide, potassium hydrosulfide, and methylamine resulted in substitution of fluorine atom in the 4-position (in the reaction with methylamine, also in the 2-positi
Deacon, G. B.,Raverty, W. D.,Vince, D. G.
, p. 103 - 114 (1977)
Grignard exchange reaction using a microflow system: From bench to pilot plant
Wakami, Hideo,Yoshida, Jun-Ichi
, p. 787 - 791 (2005)
The Grignard exchange reaction of ethylmagnesium bromide (EtMgBr) and bromopentafluorobenzene (BPFB) to give pentafluorophenylmagnesium bromide (PFPMgBr) was carried out using small- and medium-scale microflow systems consisting of a micromixer and a microheat exchanger. The results indicate that the microflow systems are quite effective. On the basis of the data obtained, a pilot that involves the Toray Hi-mixer connected to a shell and tube microheat exchanger was constructed. Continuous operation for 24 h was accomplished without any problem to obtain pentafluorobenzene (PFB) after protonation (92% yield).
Reductive elimination of C6F5-C6F 5 in the reaction of bis(pentafluorophenyl)palladium(ii) complexes with protic acids
Koizumi, Take-Aki,Yamazaki, Atsuko,Yamamoto, Takakazu
, p. 3949 - 3952 (2008)
Reductive elimination of C6F5-C6F 5 from cis-[Pd(C6F5)2L] (L = cod, bpy, and dppb) was promoted by Bronsted acids. HNO3 is a convenient acid for the formation of C6F5-C 6F5 from [Pd(C6F5) 2(cod)]. The products are controlled by the auxiliary ligand.
New catalytic systems with chemically fixed nickel complexes in the reactions of reductive activation of C-F bonds in ionic liquid media
Adonin, N Yu,Prikhod'ko, S. A.,Shabalin, A Yu.
, (2021/08/03)
The nickel complexes with bidentate nitrogen-containing ligands covalently bound to alkylimidazolium cations were obtained for the first time. By the example of the reaction of selective hydrodefluorination of hexafluorobenzene to pentafluorobenzene, it was shown that the catalytic systems ionic liquid - water - covalently bound nickel complex based on the obtained compounds are much more efficient with repeated use in comparison with unfixed nickel complexes. The decisive influence of the cationic fragment of the ionic liquid on the possibility of multiple use of nickel complexes has been established.
Stopped-Flow 19F NMR Spectroscopic Analysis of a Protodeboronation Proceeding at the Sub-Second Time-Scale
Wei, Ran,Hall, Andrew M. R.,Behrens, Richard,Pritchard, Mark S.,King, Edward J.,Lloyd-Jones, Guy C.
supporting information, p. 2331 - 2342 (2021/05/03)
In-situ NMR spectroscopic analysis of homogeneous reactions is an essential tool for mechanistic analysis in organic and organometallic chemistry. However, rapid non-equilibrium reactions, that are initiated by mixing, require specialized approaches. We report herein on a study of the factors that ensure quantitative results in a recently-developed technique for stopped-flow NMR spectroscopy. The influence of some of the key parameters on quantitation is studied by 19F NMR spectroscopic analysis of the kinetics and activation parameters for the base-catalyzed protodeboronation of highly-reactive polyfluorinated arylboronic acids, with half-lives as low as 0.1 seconds. The effects of spin relaxation, pre-magnetization, heat-transfer versus reaction enthalpy, and mixing-efficiency are analyzed in detail. We also compare and contrast choice of pulse angle, interscan delay, and use of pseudo real-time by interleaving, as means to achieve an optimal balance between temporal resolution and sensitivity.