Fluorinated cotelomers based on vinylidene fluoride (VDF) and hexafluoropropene (HFP): Synthesis, dehydrofluorination and grafting by amine containing an aromatic ring

The synthesis of C6F13CH2C(CFCFCF3)N–C2H4–C6H5 (11) from the addition of H2N–C2H4–C6H5 onto C6F13CH2CF2CF2CFHCF3 (3) is presented. C6F13CH2CF2CF2CFHCF3 (3) and C6F13CH2CF2CF(CF3)CF2H (3′) isomers were obtained from the thermal stepwise cotelomerization of vinylidene fluoride and hexafluoropropene with C6F13I, followed by the selective reduction of the iodine end atom. At 200 °C, the 3/3′ molar ratio reached 9.0. In contrast to selective reduction, dehydrofluorination led to various derivatives, which were characterized by 1H NMR and 19F NMR spectroscopy, and hence a reaction pathway could be suggested. The grafting of an amine containing an aromatic ring onto the cotelomers based on VDF and HFP occurred selectively on VDF/HFP diad and, in some instances a further step involving the formation of an imine was observed. The addition of 2-phenylethylamine onto the dehydrofluorinated intermediates was found to be quantitative.