Perfluoroalkanesulfonates

Fluotinated higher carboxyHc acids, Perfluoroalkanesulfonic acids,... 

PerfluoroaLkanesulfonic acids and thek derivatives are of commercial significance because of thek unusual acid strength, chemical stabiUty, and the surface activity of the higher members of the series (eight carbons and larger). 

The perfluoroalkane sulfonic acids were fkst reported ki 1954. Trifluoromethanesulfonic acid was obtained by the oxidation of bis(ttifluoromethyl thio) mercury with aqueous hydrogen peroxide (1). The preparation of a series of perfluoroalkanesulfonic acids derived from electrochemical fluotination (ECF) of alkane sulfonyl haUdes was also disclosed ki the same year (2). The synthetic operations employed when the perfluoroalkanesulfonic acid is derived from electrochemical fluotination, which is the best method of preparation, are shown ki equations 1—3. 

The boiling pokits of a series of perfluoroalkanesulfonic acids are Hsted ki Table 1 (2). 

The longer perfluoroalkanesulfonic acids are hydroscopic oily Hquids. Distillation of the acid from a mixture of its salt and sulfuric acid gives a hydrated mixture with melting points above 100°C. These acids show the same general solubiUties as trifluoromethanesulfonic acid, but are insoluble in ben2ene, heptane, carbon tetrachloride, and perfluorinated Hquids. AH of the higher perfluoroalkanesulfonic acids have been prepared by electrochemical fluorination (20). 

Higher perfluoroalkanesulfonates are slightly more reactive than triflates toward nucleophilic displacements. The rate constants for acetolysis of methyl nonafluorobutanesulfonate [6401 -03-2J, methyl trifluoromethanesulfonate [333-27-7] and methyl toluenesulfonate [80-48-8] are 1.49 x, ... 

Perfluoroalkanesulfonic Esters Methods Stang P J Harmack M, Synthesis 85-126 263... 

A vast variety of perfluoroalkanesulfonic esters are known, and their application in synthetic organic chemistry is increasing rapidly (for a comprehensive review, see reference 66) These compounds are readily available by the reaction of organic halides with silver perfluoroalkanesulfonate or by the reaction of an alcohol with the corresponding perfluoroalkanesulfonic anhydride or chloride Alkyl per-fluoroalkanesulfonates are powerful alkylating reagents because of the excellent... 

Perfluoroacylbenzene sulfonates, 12 174 Perfluoroacyl fluorides, 11 865 alkylation of, 11 883 Perfluoroalkanesulfonic acids, 12 191 Perfluoroalkoxy (PFA) fluorocarbon resins, 18 329... 

Oshimura M, Takasu A (2010) Controlled ring-opening polymerization of E-caprolactone catalyzed by rare-earth perfluoroalkanesulfonates and perfluoroalkanesulfonimides. Macromolecules 43 2283-2290... 

Scheme 13 Twofold Heok oouplings on 2-bromocycloalkenyl perfluoroalkanesulfonates. A Pd(OAc)2, PPhs, NEts, LiCI, DMF, 60—90°C, 24—96h. Bi As in A, but without LiCI. Tf = S02CF3, Nf = S02C4Fg.

Tetrakis(perfluoroalkanesulfonates) Zr(RFS03)4 (RF = CF3 or C2F5) have been prepared by reaction of ZrCl4 with an excess of the perfluoroalkanesulfonic acid.467 Hie mode of attachment of the perfluoroalkanesulfonate ligands is unknown. 

Palladium complexes exhibit even higher catalytic activity and produce branched acids preferentially.132 133 The selectivity, however, can be shifted to the formation of linear acids by increasing the phosphine concentration.134 Temperature, catalyst concentration, and solvent may also affect the isomer ratio.135 Marked increase in selectivity was achieved by the addition of Group IVB metal halides to palladium136 and platinum complexes.137 Linear acids may be prepared with selectivities up to 99% in this way. The formic acid-Pd(OAc)2-l,4-bis(diphe-nylphosphino)butane system has been found to exhibit similar regioselectivities.138 Significant enhancements of catalytic activity of palladium complexes in car-bomethoxylation by use of perfluoroalkanesulfonic acid resin cocatalysts was reported.139,140... 

P. J. Stang, M. Hanack, and L. R. Subramanian, Perfluoroalkanesulfonic esters methods of preparation and applications in organic chemistry, Synthesis 83 (1982). 

FLUORINECOMPOUNDS,ORGANIC - PERFLUOROALKANESULFONIC ACIDS] (Vol 11) 3-fluoro-chloramphemcol [73212-55-2]... 

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