This thesis focuses on the development of a novel nucleophilic ¹⁸F-fluorination of (hetero)arenes and of a rapid screening experiment to facilitate the application of this reaction to complex heterocyclic targets of medicinal importance. <strong>Chapter 1</strong> introduces the use of molecules labelled with fluorine-18 as tracers in positron emission tomography and reviews methods for the preparation of [¹⁸F]fluoroarenes published prior to the start of the work in this thesis. <strong>Chapter 2</strong> describes the development of a novel method for the preparation of electronically-diverse [¹⁸F]fluoroarenes from aryl boronic esters and [¹⁸F]fluoride, mediated by a copper complex. Application of this ¹⁸F-fluorodeboronation to electron-rich radiotracers is demonstrated. Methods for the preparation of [¹⁸F]fluoroarenes published after the start of the work in this thesis are reviewed. <strong>Chapter 3</strong> outlines a rapid screening experiment for assessing the tolerance of the ¹⁸F-fluorodeboronation towards heterocycles, and the use of this method to guide the retro-radiosynthesis of heterocycle-rich, medicinally relevant molecules. <strong>Chapter 4</strong> contains synthetic procedures and characterisation data for compounds in Chapters 2 and 3.