Reactions involving fluoride ion. Part 20. Competition between isomerization and nucleophilic attack on a perfluoroalkene

Abstract

Reaction of perfluoro-3,4-dimethylhex-3-ene (1) with amine gives products which arise from nucleophilic attack directly on (1) but also products derived from attack on isomers of (1), i.e. perfluoro-3,4-dimethylhex-2-ene (2) and perfluoro-3-methylene-4-methylhexane (3), promoted by fluoride ion which is generated during reaction. The products obtained depend critically on the steric requirements of the attacking amine, e.g. Et₂NH gives products arising exclusively from attack on isomer (3).