Partially fluorinated heterocyclic compounds. Part 16. Preparation of furan derivatives from pentafluorophenyl and heptafluoro-2-naphthyl prop-2-ynyl ethers with aromatic compounds, and the isolation of hydrogen-abstraction products

Abstract

Pentafluorophenyl and heptafluoro-2-naphthyl prop-2-ynyl ethers [(1) and (5)] react in N,N-diethylaniline to give among other products 2-methylfuran derivatives [(10) and (11); (15)] formed by hydrogen-abstraction reactions, and 2-(diethylaminobenzyl)furan derivatives [(13) and (14); (17) and (18)]; the 2-fluoromethylfuran (16) is also formed from (5). No aromatic substitution products are obtained from (5) with nitrobenzene or benzylidyne trifluoride. It was not possible to distinguish between homolytic and heterolytic fission of the aliphatic C–F bonds in the Claisen rearrangement intermediates (8) and (9) involved in these reactions.