The generation and chemistry of some novel perfluorinated dienes

Abstract

The work contained in this thesis is divided into three sections detailing the formation of fluorinated dienes and some aspects of their chemistry: a) Through cyclic voltammetry, an electrochemical investigation was carried out to determine the reduction potentials of several easily accessible perfluorinated alkenes. Following this, sodium amalgam was successfully used as a single electron transfer agent in order to reduce a number of these fluoroalkenes by means of selective defluorination. This has enabled a series of perfluorinated alkadienes to be prepared cleanly in good yield. A study of a variety of other means of defluorination was also investigated. b) These dienes have been subjected to attack by mono- and bi functional nucleophiles in high yielding reactions. This has enabled an unusual perfluorinated diepoxide to be synthesised which displays remarkable thermal stability. A number of novel pyrrole and pyrrolo-quinoline derivatives have also been made from a series of substituted anilines and these are discussed within a mechanistic framework in order to justify the product distributions. Finally, the reaction between potentially bi- functional carbon nucleophiles and these perfluorinated dienes has been used as a means of synthesising a series of poly(perfluoroalkyl)- substituted cyclopentadienyl anions including the pentakis(trifluoromethyl)-cyclopentadienyl anion, the formation of which could proceed by an unusual cyclisation and elimination mechanism. c) Charge transfer salts have been prepared by complexation of decamethylferrocene with various fluorinated dienes. These salts have been the subject of X-ray crystallographic and molecular magnetic susceptibility studies. No signs of organic ferromagnetism were observed.