Alkyl perfluoro carboxylates

Photochemically induced reduction of alkyl perfluoro carboxylates in hexa-methylphosphoramide (FfMPA) can replace one, two, or (in the case of tn-fluoroacetate) three a-fluonne atoms with hydrogen [7, S] (equation 5) Chlorine-containing fluorocarboxylates preferentially lose a-chlorme and may even lose P-chlorinc in preference to a fluonne [9] (equation 6) Cyclic a-fluoroketones are also defluonnated photochemically [10] (equation 7)... 

During electrochemical fluorination retention of important functional groups or atoms in molecules is essential. Acyl fluorides and chlorides, but not carboxylic acids and anhydrides (which decarboxylate), survive perfluorination to the perfluorinated acid fluorides, albeit with some cyclization in longer chain (>C4) species [73]. Electrochemical fluorination of acetyl fluoride produces perfluoro-acetyl fluoride in 36-45% yields [85]. Electrochemical fluorination of octanoyl chloride results in perfluorinated cyclic ethers as well as perfluorinated octanoyl fluonde. Cyclization decreases as initial substrate concentration increases and has been linked to hydrogen-bonded onium polycations [73]. Cyclization is a common phenomenon involving longer (>C4) and branched chains. a-Alkyl-substituted carboxylic acid chlorides, fluorides, and methyl esters produce both the perfluorinated cyclic five- and six-membered ring ethers as well as the perfluorinated acid... 

The quadrupolar 2H spin-lattice relaxation of specifically deuterated surfactants, such as the methyl deuterated n-alkyl phosphocholine surfactants, also shows a concentration dependence. The CMC of dodecyl phosphocholine was determined by exploiting the difference in the 2H spin-lattice relaxation times of the monomers versus the micellar state.68 Quadrupole splittings of 14N were also used to characterize the micellization process of short-chain perfluoro-carboxylic acid salts.69... 

Electrochemical fluorination of a-cyclohexenyl-substituted carboxylic (acetic, propanoic, butanoic, and pentanoic) acid esters (methyl, ethyl, and propyl) results in a series of both perfluoro-9-alkyl-7-oxabicyclo[4 3 OJnonanes and per-fluoro-8-alkoxy-9-alkyl-7-oxabicyclo[4.3.0]nonanes [<8S] (equation 19)... 

WITTIG OLEFINATION, OF PERFLUORO ALKYL CARBOXYLIC ESTERS, 75,153... 

Carbocarbonylation [216] of alkyl halide with a perfluoro substituent leads directly to the analogous carboxylic acids and esters, provided the ) -hydride elimination is slower than CO insertion. The use of PdCl2(dppf) in the esterification of 68 gives... 

Another strategy to recover the catalyst is suggested by the concept of fluorous biphasic systems . An application of this strategy to cyclopropanation with methyl diazoacetate using as catalyst rhodium(II) carboxylates featuring a long perfluoro-alkyl chain showed that the catalyst could be reused several times without significant loss of activity [32 c]. 

Perfluoro alkanoic acids have been prepared from perfluoro alkyl iodides by carboxylation in the presence of a zinc-copper couple in DMSO, in yields of 50% or greater. 

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