This thesis describes the reactions of some highly fluorinated aromatic and heteroaromatic compounds, in particular derivatives of naphthalene, quinoline and isoquinoline. Chapter 1 provides a general introduction to the preparation, reactions and applications of fluorine containing organic materials. Chapter 2 describes the reactions of some quinoline- and isoquinoline- thiolates with dimethyl acetylenedicarboxylate in an attempt to form six membered heterocycles. Chapter 3 describes nucleophilic substitution reactions of heptafluoro- quinoline and -isoquinoline with sulphur and oxygen nucleophiles. The sulphur nucleophiles are found to attack the 6- site in the isoquinoline and the 4- site in the quinoline. The oxygen nucleophiles attack the 1- site in the isoquinoline and 2- and 4- sites in the quinoline. Chapter 4 describes competition experiments of heptafluoro-quinoline and -isoquinoline with nucleophiles. Relative rates of attack at the 1- position and 6- position in the isoquinoline are determined for a variety of nucleophiles. The relative rates of two nucleophiles are determined for 4- attack in the quinoline. The relative reactivities of the two heterocycles are determined for two different nucleophiles. Chapter 5 describes the pyrolysis of heptafluoro-2-naphtiiyl propynoate which yield two difluoro-butenone derivatives. These decarbonylate under further pyrolysis to yield a 1,1-difluorocyclopropene. All the products were identified by X-ray crystallography. Chapter 6 gives experimental details for Chapter 2 to Chapter 5.