Methyl pentafluorophenyl ether

Perfluorobenzene when treated with sodium methoxide produces methyl pentafluorophenyl ether (10).so... 

These results clearly show that the potential energy surface can contain a series of minima. The fact that selectivity in re-attack by the F ions can be observed indicates that the differences between the energy barriers for the secondary reactions control the distribution of the final products. The multistep character of these processes is further illustrated by the reactions observed when enolate anions are used as reactant ions. The ambident enolate anions may react with methyl pentafluorophenyl ether at the carbon or the oxygen site. If they react with the carbon site at the fluorine-bearing carbon atoms, then the molecule in the F ion/molecule complex formed contains relatively acidic hydrogen atoms so that proton transfer to the displaced F ion may occur. An example is given in (47) where the enolate anion, generated by HF loss, is not observed. An intramolecular nucleophilic aromatic substitution occurs instead and leads to a second F ion/ molecule complex. The F" ion in this complex then re-attacks the substituted benzofuran molecule formed, either by proton transfer or SN2 substitution. 

Methyl pentachlorophenyl ether 9614 Methyl pentafluorophenyl ether... 

Tr ifluoroacetate has been determined in seawater in amounts down to 32 ng/1 by extraction with methyl tert butyl ether and derivatised with pentafluorophenyl diazomethane prior to gas chromatography mass spectrometry (negative ionisation) [541],... 

Therefore, if ratios are given, these must be considered with great care, especially if irradiation times were long. Ortho adducts formed by intramolecular photocycloaddition are even less stable than those from intermolecular reactions. Only from pentafluorophenyl prop-2-enyl ether [111], 2-methyl-6-(4-fluo-rophenyl)hex-2-ene [112], and l-(2-methoxybenzyloxy)-3-methylbut-2-ene [113] have primary ortho adducts reportedly been isolated. The many secondary... 

Bis[trifluoromethyl] tellurium and bis[pentafluorophenyl] tellurium react with dimethyl zinc or dimethyl cadmium with stepwise replacement of the perfluoroorganyl groups by methyl groups2,3. These reactions were carried out in trichlorofluoromethane in the presence of bis[2-ethoxyethyl] ether as the complexing agent for the perfluoroorgano element compounds2. 

Pentafluorophenyl propargyl ether isomerizes in the gas phase on silica gel at 370°C to give 2-monofluoromethyl-4,5,6,7-tetrafluorobenzo[6]-furan [81JCS(P1)1417]. Via the same route, naphtho[2,l-/ ]furans [82JCS(P1)107, 82JFC(20)173] and 4,5,6,7-tetrafluoro-2,3-dihydro-2-methyl-1-benzothiophene [81JCS(P1)1659] can be synthesized (Scheme 54). 

In a project on electron-deficient isocyanides, Lentz studied the reactivity of pentafluorophenyl isocyanide 4a, isocyanoacetonitrile 4b, pentacarbonylchromium diisocyanomethane 4c, and 2,2,2-trifluoroethylisocyanide 4d toward bis[tris(trimethylsilyl)methyl] diphosphene 3. Combination of the reactants in pentane or diethyl ether at ambient temperature led to the formation of the expected diphosphirane imines 5a-5d as yellow crystals in moderate yields (Equation 2). For the success of this process very bulky substituents at the P=P unit and electron-withdrawing groups at the nitrogen atom are required, which is evident by the decrease of thermostability in the series 5c m 5a >5b>5d <1998JFC73, 1999ZFA1934>. 

A fluorinated poly(arylene ether sulfide) (PSI) is prepared from the condensation of bis-(pentafluorophenyl)-sulfide with 4,4 -(trifluoromethylphenyl-isopropyhdene)diphenol, which is a methyl fluorinated bisphenol A. " ... 

Competition between the formation of Diels-Alder and ene-reaction products also occurs in the reaction of tetrafluorobenzyne (generated from pentafluorophenyl-lithium) with 7-dehydrocholesteryl methyl ether (21) as found in the reaction involving cyclohexa-1,3-diene (see above), and in keeping with the enhanced dienophilic character of tetrafluorobenzyne, the ratio of the Diels-Alder adduct (22) (22 % yield) to ene products [only (23) (51 %) was isolated] is much higher than that found with benzyne itself. Attack of tetrafluorobenzyne (from pentafluorophenylmagnesium chloride) on hex-l-ene and cis- or rraK5-hex-3-ene is claimed to yield the ene-reaction product (24) and a mixture of adduct (25) and ene-reaction product (26), respectively benzyne attacks the hex-3-enes less readily than tetrafluoro-... 

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