Perfluoroalkylation using Perfluoro Acid Anhydrides

Kawamura and Sodeoka have reported perfluoroalkylating reactions of alkenes using acid anhydrides as a perfluoroalkyl source. According to their report, a peroxide derivative of trifluoroacetic anhydride (TFAA) prepared from TFAA and a urea-H₂O₂ adduct acts as a trifluoromethylating species in the presence of tetrakis(acetonitrile)copper(I) hexafluorophosphate catalyst, and successfully reacts with alkenes. The same type of reaction proceeds even when using peroxide derivatives of perfluoro acid anhydrides, and affords the related perfluoroalkylated products. The reaction pathway is considered to proceed via the radical intermediate generated from diperfluoroalkylcarbonyl peroxides and the copper(I) complex by single electron transfer. On the other hand, when alkenes having a phenyl group with an appropriate length of a carbon chain are used for this perfluoroalkylation, the intramolecular radical cyclization is carried out under Cu(I) salt free conditions and the desired perfluoroalkyl group-substituted bicyclic compounds are obtained.