Betaines perfluoroalkyl

Polyethers, alkanolamides, alkyls, alkylethoxylates, amines, benzyls, carbohydrates, esters, perfluoroalkyls Alkyl-, amidoimidazoline- and carboxy-quaternary ammonium salts Betaines, phosphobetaines, sulfobetaines... 

Figure 1.15 t-Butyl- (a) and perfluoroalkyl- (b) substituted betaine dyes for polarity measurements in less polar or highly fluorous solvents... 

Carnitine is at the origin of two types of fluorinated surfactants. The perfluoroalkyl-acylcarnitines (28) (Scheme 24), obtained with satisfactory yields (44-80%), show good surfactant characteristics [60], The synthesis of Ai-perfluoroalkyl carnitine (29) (Scheme 25) is less efficient, and its physicochemical properties have not been evaluated [61]. The betaines of perfluoro-alkyl a,co-amino acids (30) (Scheme 26) are accessible in a similar manner [62]. They are good surface agents [63]. 

Among the numerous approaches described to graft a perfluoroalkyl chain on an aminoacid skeleton, the methods allowing one to create a C-C bond between the fluorinated part and the amino acid are of special interest. The access to this less frequently encountered type of compound uses classical methods of synthesis, such as that leading to the perfluoroalkyl-glycine 31 (Scheme 27). The compounds 31 are barely soluble, except for the betaine derivatives 32, which are obtained with very poor yields, however [64], The perfluoroalkyl-glycines have been condensed on cholic acid (Scheme 28) to give products 33, also with unsatisfactory yields [37]. 

Chem. Descrip. Perfluoroalkyl betaine Ionic Nature Amphoteric... 

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