1516-64-9Relevant academic research and scientific papers
Perfluoroisopropylcadmium and copper: preparation, stability and reactivity
Nair, Haridasan K.,Burton, Donald J.
, p. 341 - 351 (1992)
Perfluoroisopropylcadmium can be prepared in excellent yield (98percent) from (CF3)2CFI and activated cadmium powder in DMF at room temperature under degassed conditions.The resultant cadmium reagent undergoes metathesis with copper(I) salts to give perfluoroisopropylcopper, in quantitative yield.While perfluoroisopropylcopper is stable in DMF at room temperature under nitrogen, the cadmium counterpart decomposes to a mixture of dimers and trimers of hexafluoropropene, under the same conditions.Sulfur dioxide can be inserted into the cadmium-carbon bond in perfluoroisopropylcadmium while no reaction was observed with corresponding copper reagent.No stable F-alkylcadmium could be obtained from the raction of CF3CF2CFICF3 with either Cd powder or Me2Cd; only the elimination product, CF3CF=CFCF3, was observed.Perfluoroalkylation reactions with F-isopropylcadmium/copper in DMF met with limited success.
Synthesis of tris- and tetrakis(pentafluoroethyl)silanes
Steinhauer, Simon,Bader, Julia,Stammler, Hans-Georg,Ignat'Ev, Nikolai,Hoge, Berthold
supporting information, p. 5206 - 5209 (2014/05/20)
The synthesis and complete characterization of functional, highly Lewis acidic tris(pentafluoroethyl)silanes as well as tetrakis(perfluoroalkyl)silanes Si(C2F5)4 and Si(C2F 5)3CF3 by direct fluorination is described. The reaction of SiCl4 with LiC2F5 invariably affords (pentafluoroethyl)fluorosilicates. To avoid silicate formation by fluoride transfer from LiC2F5 the Lewis acidity of the silane has to be decreased by electron-donating substituents, such as dialkylamino groups. The easily accessible Si(C2F5) 3NEt2 is a valuable precursor for a series of tris(pentafluoroethyl)silanes. Special eFfects: functional and highly Lewis acidic tris(pentafluoroethyl)silanes as well as the tetrakis(perfluoroalkyl) silanes Si(C2F5)4 and Si(C2F 5)3CF3 are prepared. The two tetrakis species were formed in the direct fluorination of tris-(pentafluoroethyl)ethyl- and methylsilane. Si(C2F5)4 was characterized by X-ray crystallography (see figure).
Reactions of half-sandwich ethene complexes of rhodium(I) toward iodoperfluorocarbons: Perfluoro-alkylation or -arylation of coordinated ethene versus oxidative addition
Gil-Rubio, Juan,Guerrero-Leal, Juan,Blaya, Maria,Vicente, Jose,Bautista, Delia,Jones, Peter G.
experimental part, p. 1287 - 1299 (2012/04/10)
Perfluoroalkylation or perfluoroarylation of coordinated ethene takes place when complexes [Rh(η5-Cp*)(η2-C 2H4)2] or [Rh(η5-Cp*) (η2-C2H4)(PR3)] react with IRF, to give complexes [Rh(η5-Cp*)(CH 2CH2RF)(μ-I)]2 (RF = CF(CF3)2(1a), CF(CF3)CF2CF 3 (1b), or C(CF3)3 (1c)) and [(η5-Cp*)IRh(μ-I)2Rh(η5- Cp*)(CH2CH2RF)] (2a-c), or [Rh(η5-Cp*)(CH2CH2R F)I(PR3)] (R = Me, RF = CF(CF3) 2 (3a), C(CF3)3 (3c), C6F 5 (3d); R = Ph, RF = CF(CF3)2 (3a′), CF2C6F5 (3e′)), respectively. Bridge splitting reactions of 1a, 1b, or 1c with phosphines afford complexes [Rh(η5-Cp*)(CH2CH2R F)I(PR3)] (3a, 3a′, 3c; RF = CF(CF 3)2, R = iPr (3a″); RF = CF(CF3)CF2CF3, R = Me (3b), Ph (3b′)). In contrast, oxidative addition dominates over addition to ethene in the reactions of [Rh(η5-Cp*)(η2-C2H 4)(PMe3)] with IRF (RF = CF 2C6F5, nC3F7, nC4F9, CF=CF2) and in the reaction of [Rh(η5-Cp)(η2-C2H 4)(PMe3)] with InC4F9, affording complexes of the type [Rh(η5-C5R 5)(RF)I(PMe3)] (4e-h and 5, respectively). The reaction of [Rh(η5-Cp*)(η2-C 2H4)(PR3)] with ICF(CF3)CF 2CF3 gives a mixture of cis- and trans-octafluoro-2-butene as the main fluoroorganic reaction product. Evidence for the intermediacy of RF- anions in these reactions has been obtained. 3a′ reacts with AgOTf (OTf = O3SCF3) and XyNC or CO to give complexes [Rh(η5-Cp*){CH2CH 2CF(CF3)2}(CNXy)(PPh3)]OTf (6) or [Rh(η5-Cp*){C(O)CH2CH2CF(CF 3)2}(CO)(PPh3)]OTf (7), respectively. Complex [Rh(η5-Cp*)I(py)(PMe3)]BF4 (8) was obtained either by reaction of (1) [Rh(η5-Cp*) (η2-C2H4)(PMe3)] with [I(py)2]BF4 or (2) [Rh(η5-Cp*)I 2(PMe3)] with AgBF4 and py. The crystal structures of 1a, 1b, 3c, 4g, 7, and 8 have been determined.
Fluorine chemistry - Wittig based synthesis of volatile organofluorine compounds
Bhadury, Pinaki S.,Singh, Sapna,Sharma, Mamta,Palit, Meehir,Jaiswal, Devendra K.
, p. 1186 - 1191 (2007/10/03)
A simple and practical method has been developed for the synthesis and characterization of several interesting classes of volatile organofluorine compounds from fluorophosphonium salts via their in situ generated corresponding ylides. The fluorinated phosphonium ylides react with hexafluoroacetone in DMF to generate perfluoroisobutylene, whereas in the presence of bromine or iodine containing electrophiles, tetrafluoroethylene, perfluoro-2-butene, perfluorocyclobutane, and 1H-heptafluoropropane are obtained.
Solvents for use in fluorination reactions
-
, (2008/06/13)
A method of fluorinating an organic compound comprising reacting an organic compound with a fluorinating agent characterized in that a perfluorocarbon compound is present in the reaction medium. The perfluorocarbon compound may replace an amount of a solvent which would otherwise be required for the reaction to proceed efficiently. The perfluorocarbon compound is readily recoverable after reaction and may be re-used in subsequent reactions. Additives to the reaction medium, such as 18-crown-6, may increase the amoun of solvent which may be replaced. The method is beneficial where solvent consumption would otherwise be large, or where solvent recovery would otherwise be difficult.
Perfluorocarbon fluids as solvent replacements
Chambers, Richard D.,Edwards, Andrew R.
, p. 3623 - 3627 (2007/10/03)
Perfluoroperhydrophenanthrene 1 may be used as a 'bulking agent' to minimise the problem of solvent recovery in halogen exchange ('Halex') reactions for the preparation of octafluorocyclopentene 8, and chlorofluoro-pyridine, -pyrimidine and -benzene derivatives. New 'one-pot' procedures for the syntheses of hexafluorobut-2-yne 3, octafluorobut-2-ene 11 and hexafluorocyclobutene 7 are described.
NEW DATA ON THE MECHANISM OF THERMAL TRANSFORMATIONS OF PERFLUOROOLEFINS. BIRADICAL INTERMEDIATES
Buravtsev, N. N.,Kolbanovskii, Yu. A.,Ovsyannikov, A. A.
, p. 1891 - 1900 (2007/10/03)
It was shown by kinetic spectroscopy that biradicals are formed during the thermal gas-phase transformations of perfluoroolefins and perfluorinated small rings under strictly homogeneous conditions of pulsed adiabatic compression.The role of these radicals in the mechanism of the transformations of perfluoroolefins is discussed.The rate constants and equilibrium constants of some elementary stages are determined.
INFLUENCE OF CROWN ETHERS ON THERMAL DECARBOXYLATION OF SALTS OF PERFLUOROCARBOXYLIC ACIDS
Podol'skii, A. V.,Khonina, T. G.,Filyakova, T. I.,Kachalkova, M. I.,Kodess, M. I.
, p. 1977 - 1979 (2007/10/02)
Thermal decarboxylation of potassium salts of perfluorocarboxylic acids in the presence of 20 mole percent of crown ethers takes place in 1 h at 180 deg C and gives internal perfluoroolefins in yields of up to 95percent.The predominance in product mixtures of isomers whose double bond is adjacent to the trifluoromethyl group is associated with kinetic control of the reaction.The kinetic parameters of the process have been found and the relative activities of a series of crown ethers have been established.A scheme is advanced to show their influence on the reaction studied.
ELECTROPHILIC ISOMERIZATION OF SUBSTITUTED PERFLUOROCYCLOPROPANES UNDER THE EFFECT OF SbF5
Chepik, S. D.,Petrov, V. A.,Galakhov, M. V.,Belen'kii, G. G.,Mysov, E. I.,German, L. S.
, p. 1674 - 1680 (2007/10/02)
Perfluoro(alkoxycyclopropanes) are isomerized on heating in the presence of SbF5 into perfluoro(2-alkoxypropylenes), while perfluoro(alkylcyclopropanes) are isomerized into the corresponding internal fluoroolefins under the effect of SbF5.
ISOMERIC COMPOSITION OF THE PRODUCTS FROM THE REACTION OF POLY- AND PERFLUORO-1-ALKENES WITH ALKALI-METAL FLUORIDES IN APROTIC SOLVENTS
Filyakova, T. I.,Kodess, M. I.,Peschanskii, N. V.,Zapevalov, A. Ya.,Kolenko, I. P.
, p. 1651 - 1658 (2007/10/02)
The reaction of normal perfluoro-1-alkenes with alkali-metal fluorides in polar aprotic solvents was investigated, and the isomeric composition of the products was determined.The rearrangement of perfluorinated olefins catalyzed by the fluoride ion is stereoselective and leads to the preferential formation of the trans isomers of internal perfluoroalkenes.This is explained from the standpoint of a carbanionic mechanism.The (19)F NMR spectra of the cis and trans isomers of the perfluoroalkenes were obtained, and their relationships are discussed.For the cis isomers the signals of all the groups in the (19)F NMR spectrum are observed in the downfield region from the corresponding signals of the trans isomers.This effect is strongest for substituents situated directly at the double bond.
