REACTIONS OF PERCHLOROFLUORO COMPOUNDS VI. REARRANGEMENT OF HIGHER PERCHLOROFLUOROOLEFINS AND THEIR REACTIONS WITH NUCLEOPHILES AND ELECTROPHILES

Article abstract of DOI:10.1016/S0022-1139(00)82932-2

The fluoride ion induced isomerization of CFCl2CF2CFClCF2CF=CF2 (1) gave only trans isomer CFCl2CF2CFClCF=CFCF3 (2), then trans CFCl2CF2CCl=CFCF2CF3 (3) and trans CFCl2CF2CF=CFCF2CF3 (4), with the latter in predominance, while AlCl3-catalyzed isomerisation of 1 gave only 2 and 3.No cis isomer could be detected.Such isomerization was terminated once a chlorine atom was linked to the double bond.Reactions of perchlorofluoroolefins 1, 2 and 3 with various nucleophiles have been studied.With terminal olefin 1, C-1 was exclusively attacked by nucleophiles with the formation of three kinds of products<1>.In 2, merely C-2 was attacked and as a chlorine atom was just located at the allylic position, the reaction only proceeded through a S_N2' mechanism.In 3, only C-4 was attacked and no protonation product could be found.Competitive reaction showed the reactivity of these three perchlorofluoroolefins decreased in this order: 1 > 3 > 2, which was directly related to the polarity of double bond.Only 1 reacted with electrophiles under normal conditions.