Perfluoro-carboxylic acid

With diiodo compounds, the mono and diesters can be selectively obtained (Eq. 14). These are useful precursors to valuable perfluoro carboxylic acids. 

These products are precursors of perfluoro carboxylic acids while the fluorosulfates derived from secondary and tertiary hydrofluorocarbons provide... 

The oxidation of perfluorinated sodium sulfinates promoted by UV irradiation affords a simple and effective method for the synthesis of the corresponding perfluoro carboxylic acids 24 (R = H) or their esters 24 (R = Me). The reaction conditions are mild enough that the per-fluorovinyl ether grouping in the acid chain remains unaffected.313... 

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... 

Tanahe, Y Matsuo, N. Ohno, N. Direct perfluoroalkylation including trifluoromethy-lation of aromatics with perfluoro carboxylic acids mediated hy xenon difluoride. J. Org. Chem. 1988, 53, 4582-A-585. 

Fedorova, G.B. Dolgopol skii, I.M. Suvorova, M.A. Gubanov, V.A. Gracheva, P.E. Bifunctional derivatives of perfluorocarboxyhc acids. IV. S3mthesis of co-cyano-substituted chlorides of perfluoro carboxylic acids. Zh. Org. Khim. 1973, 9(11), 2211-2214. 

Germain and Commeyras have found that perfluorosulfonic esters and fluorosulfates are formed in high yields by direct anodic oxidation of Rfl in perfluoroalkane sulfonic acids and fluorosulfuric acid (Eqs. 34 and 35). With diiodo compounds, the mono- and diesters can be selectively obtained (Eq. 36). These are useful precursors to valuable perfluoro carboxylic acids. 

These products are precursors of perfluoro carboxylic acids while the fluorosulfates derived from secondary and tertiary hydrofluorocarbons provide perfluoro ketones, and starting from the IH-perfluoro bicyclo[2.2.1]heptane, the corresponding perfluoro teriaiy alcohol is... 

The last type of arsenical containing the As—O bond to be considered is one that has received very little attention. These are derivatives like the acetates and trifluoroacetates which are obtained by reacting alkoxyarsines with acetic anhydride 337), arsenic oxides with perfluoro carboxylic acids 345), and haloarsines with silver trifluoroacetate 222). 

Fig. 1 Simplified mechanism for the atmospheric degradation of 8 2 FTOH into perfluoro-carboxylic acids (red box), Wallington et al. [1]...

Tanabe Y, Matsuo N, Ohno N (1988) Direct perfluoroalkylation including trifluoromethylation of aromatics with perfluoro carboxylic acids mediated by xenon difluoride. J Oig Chem 53 4582-4585. doi 10.1021/jo00254a033... 

For IPMCs, their performances critically depend on ionic polymer used. Ionic polymers usually used for the IPMC are perfiuorosulfonic acid or perfluoro-carboxylic acid polymers, of which the typical chemical structures are shown in Fig. 1. One can obtain various types of thin films made fi om perfiuorosulfonic acid fi-om E. I. du Pont de Nemours and Company as commercial products (Nafion). 

Sharma, R., R. Pyter, P. Mukerjee, Spectrophotometric determination of perfluoro carboxylic acids (heptanoic to decanoic) and sodium perfluorooctanoate and decyl sulfate in mixtures by dye-extraction. Anal. Lett., 1989,22, 999-1007. 

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... 

Carboxylic acids react with xenon difluoride to produce unstable xenon esters The esters decarboxylate to produce free radical intermediates, which undergo fluonnation or reaction with the solvent system Thus aliphatic acids decarboxylate to produce mainly fluoroalkanes or products from abstraction of hydrogen from the solvent Perfluoro acids decarboxylate in the presence of aromatic substrates to give perfluoroalkyl aromatics Aromatic and vinylic acids do not decarboxylate [91] (equation 51)... 

The carbonyl carbon of perfluoro acyl halides and carboxylic acids can be converted to a trichloromethyl group [67] (equation 54)... 

The decarboxylation reactions of fluonnated carboxylic acids are similar to those of their nonfluonnated counterparts, but predictably many exceptions exist The oxidation of the potassium salts of perfluoro acids with potassium persulfate leads to decarboxylation and coupling [93] (equation 59)... 

Esters of [1-(diethoxyphosphinyloxy)perfluoro-l-alkene]-phosphonic acid appear to be effective reagents for the synthesis of perfluoro-a,B-unsaturated carboxylic acids and their derivatives presumably an initially-generated perfluoroketene (166 ) is acted upon by a nucleophile (NuH=RNH2, I NH, or ROH). The ( E) / (Z) ratio of the product components increases with increasing length of R. 2 ... 

A complex reaction between perfluoro 2-methylpent-2-ene and carboxylic acids in the presence of potassium carbonate and Aliquat produces the acid fluoride, as the major product, with variable amounts of the 3-acyloxy perfluorinated alkene [37]. The procedure has little value for the synthesis of either compound. 

Oxidation of a number of substituted ethenylcyclopropanes to propanecarboxy-lic acids was achieved with RuCyaq. Na(10 )/CCl -CH3CN (Eig. 3.19) [342], while perfluoro alkenes were cleaved by RnO /aq. IO(OH)3, Na(ClO) or CH3COOOH/Ereon 113 to carboxylic acids [343] anthocyanidins, flavones, chal-... 

Oxidation of diethyl 2-aUyl-2-hydroxypentanedioate by RnCyaq. Na(IO )/ CHjCN-EtOAc gave triethyl homocitrate and the corresponding lactone [209]. Oxidation of cyclopentene to glutaric acid by RnCyaq. Na(C10)/CCl or CH Cl showed that addition of CHjCN and also NaOH greatly improved yields [210]. Perfluoro alkenes were cleaved by Ru02/IO(OH)j, Na(ClO) or CH COOOH/water-Freon 113 to carboxylic acids CO was also formed or, in the case of perfluoropro-pene, pefluoroacetic acid and COF (Table 3.6) [211]. 

Perfluoropropene (1) can be directly oxidized to perfluoro-1,2-epoxypropane (2) by a variety of oxidizing reagents, e.g. oxygen, hydrogen peroxide.50 s2 Pcrfluoro-1,2-epoxypropane (2) can fluorinate carboxylic acids to their corresponding acid fluorides in the presence of tertiary amines.52 55... 

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