Synthesis of environmentally relevant fluorinated surfactants--a review.
In the past years there has been a growing interest in fluorinated persistent organic pollutants such as perfluorooctanesulfonic acid, perfluorooctanesulfonamides, perfluorinated carboxylic acids and fluorotelomer alcohols. Although these compounds have probably been present in the environment for many decades, we are only now beginning to realize that these environmental contaminants may have serious environmental and health effects. This article gives a state-of-the-art review of synthetic approaches that have been employed for the synthesis of these environmentally relevant fluorinated compounds. Perfluorooctanesulfonic acid derivatives, in particular, pose a problem because only a few perfluorooctanesulfonic acid derivatives are available from commercial sources--a fact that limits the ability of researchers worldwide to further study these compounds. Because of the limited literature available, this article also describes synthetic approaches for shorter chain homologues or perfluoroether analogues that can potentially be applied for the synthesis of perfluorooctanesulfonic acid derivatives. The preparation of typical starting materials for the synthesis of perfluorooctanesulfonic acid derivatives such as the perfluoroalkanesulfonyl fluorides and chlorides will be discussed. Subsequently, their conversion into relevant perfluoroalkane sulfonate salts (R(F)SO3M), sulfonamides (R(F)SO2NH2), N-alkyl sulfonamides (R(F)SO2NHR, R = alkyl), N,N-dialkyl sulfonamides (R(F)SO2NR2, R = alkyl), sulfonamidoethanol (R(F)SO2NRCH2CH2OH, R = -H, -CH3 or -C2H5) and sulfonamidoacetates (R(F)SO2NRCH2CO2H, R = -H, -CH3 or -C2H5) will be described. Many perfluorinated carboxylic acids and fluorotelomer alcohols are available from commercial sources. The review of the synthesis of these two classes of fluorinated compounds includes a review of their industrial synthesis and the synthesis of relevant degradation products.
Lehmler
Hans-Joachim
HJ
Department of Occupational and Environmental Health, College of Public Health, University of Iowa, 100 Oakdale Campus #124 IREH, Iowa City, IA 52242-5000, USA. hans-joachim-lehmler@uiowa.edu
D017738:Alkanesulfonic Acids / Q000138:chemical synthesis*; D002264:Carboxylic Acids / Q000737:chemistry; D002625:Chemistry, Organic / Q000379:methods*; D002712:Chlorides / Q000737:chemistry; D005459:Fluorides / Q000737:chemistry; D005466:Fluorocarbons / Q000138:chemical synthesis*; D006845:Hydrocarbons, Fluorinated / Q000138:chemical synthesis*; D008956:Models, Chemical; D013449:Sulfonamides / Q000138:chemical synthesis; D013501:Surface-Active Agents / Q000138:chemical synthesis*
D017738:Alkanesulfonic Acids; D002264:Carboxylic Acids; D002712:Chlorides; D005466:Fluorocarbons; D006845:Hydrocarbons, Fluorinated; D013449:Sulfonamides; D013501:Surface-Active Agents; C063900:perfluorooctanesulfonamide; C076994:perfluorooctane sulfonic acid; D005459:Fluorides