Cyclisations via fluoride ion induced isomerisations: a route to some novel perfluoroheterocyclic compounds

Abstract

In the presence of caesium fluoride tetrafluoroformaldehyde azine reacts with difunctional perfluoroacyl fluorides of the structure [CF₂]_n(COF)₂ to produce perfluoroheterocyclic compounds of the general structure CF₃[graphic omitted] (n= 2 to 4). A heterocycle is also produced with oxalyl fluoride, but with carbonyl fluoride the major product is a substituted hydrazine.

U.v. photolysis of tetrafluoroformaldehyde azine with perfluoroglutaryl and perfluoroadipyl fluoride produces perfluoro-(N-methyl lactams) in low yield.

The above heterocycles are photolytically unstable and decarbonylate when irradiated with u.v. light, resulting in ring contraction.