Solvolysis reactions of bis(difluoramino)ethylenes: a route to nitrenium ions

Abstract

The reaction of tetrafluorohydrazine with acetylenes in inert solvent gives α,α-(fluorodifluoramino)fluorimines via unstable bis(difluoramino)- ethylenes. Under solvolytic conditions the rearrangement involves Sn1 cleavage of the NF bond and the formation of a mesomeric nitrogen-carbon cation. The resulting ion pair can collapse to the α,α-(fluorodifluoramino)- fluorimine, which is stable under the reaction conditions, or react with solvent to give solvolysis products. Unsymmetrical acetylenes yield rearranged and solvolysis products from reaction of either of the dissimilar difluoramine groups.