Radical additions to fluoroolefins. Thermal reaction of perfluoroallyl chloride with perfluoroalkyl iodides as a selective synthesis of terminal perfluoroolefins

Article abstract of DOI:10.1016/0022-1139(95)03202-O

Reaction of perfluoroallyl chloride with perfluoroalkyl iodides, R_FI (R_F = C4F9, C6F13, C8F17), in an autoclave at 180-250 deg C gave terminal perfluoroolefins, CF2=CF-CF2-R_F (2-4) as the sole reaction products.Isomeric fluoroolefins containing an internal double bond and telomeric products were not observed in the reaction mixture.The yields were dependent on the reaction temperature and on the chain length of R_FI: the highest preparative yield of olefin 2 (R_F = C4F9) was obtained at 200 deg C (26percent), while in the syntheses of olefins 3 and 4 (R_F = C6F13 and C8F17, respectively) highest yields were achieved at 250 deg C (41percent and 74percent, respectively).The presence of CuI or a peroxide initiator had a negative influence on the yield of products.Formulae have been assigned to the fragments in the mass spectra of products 2-4, and fragmentation sequences have been proposed. - Keywords: Perfluoroallyl chloride; Perfluoroalkyl iodides; Perfluoro-1-alkenes; Radical addition; Thermal initiation; Mass spectrometry