Organic perfluoroalkyl derivatives

Incorporation of CO2 into organic perfluoroalkyl derivatives by electrochemical methods... 

We have been interested in tbe carbon dioxide fixation into organic substrates for tbe synthesis of speciality products of the carboxylic acid family. We focussed our attention on tbe formation of new carbon-carbon bonds between CO2 and perfluoroalkyl derivatives, particularly perfluoroalkyl olefins. The perfluorinated chain being highly hydrophobic, the expected perfluoroalkyl carboxylic acids are precursors of amphiphilic molecules, of interesting applicability in the field of surfactants and medicinal chemistry [1]. 

For many organic compounds that accumulate in lipids, bio accumulation potential can be estimated from the Kow. Since perfluoroalkyl compounds are inherently oleophobic, and do not partition preferentially to lipid rich tissues [67], the K0w is not a useful predictor of bioaccumulation and direct evidence derived from the laboratory or field is required. Additionally, tissue concentrations of perfluoroalkyl substances should never be lipid normalized. The dietary accumulation, bioconcentration, and biomagnification potential of various perfluoroalkyl carboxylates and sulfonates have been assessed in the laboratory and in the Great Lakes food web (Table 4). 

Perfluoroalkyl-lithium derivatives are thermally unstable and their use in organic synthesis has been limited by competing (3-elimination processes [29]. Pentafluoroethyl-lithium has a half-life of around 8 h at —78° C [30]. In complete contrast, perfluorinated bridgehead lithio derivatives are much more stable since, in these cases, elimination of LiF would contravene Bredt s rule and would, therefore, be a higher-energy process. Consequently, perfluoroadamantyl-lithium is stable at 0° C for several days [31] (Figure 6.22). 

Much of the research on the SbCls-catalyzed halogenation of arenes has focused on the chlorination and bromination of perfluoroalkyl-substituted aromatics [14]. The reaction of organic disulfides with electron-rich aromatic compounds under catalysis with SbCls and AgSbFg affords unsymmetrical aryl sulfides in modest yields [15a]. Electrophilic sulfinylation and sulfonation can be similarly effected by SbCls [15a-c]. Alkyl- and halobenzenes give thiocyano derivatives when treated with a mixture of SbCls and Pb(SCN)2 in CCI4 [16],... 

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