The synthesis of arylsulfides from arylhalides via visible light photoredox catalysis

This thesis describes the development of a reaction to prepare aryl sulfides from aryl iodides under visible light photoredox catalysis. Visible light is used to excite a photocatalyst which leads to an oxidative catalytic cycle. The excited photocatalyst reduces a chosen aryl iodide forming an aryl radical to undergo electrophilic addition with a disulfide to form a desired aryl sulfide. This research addresses some of the limitations of traditional transition-metal catalysed cross-coupling reactions, through the development of a radical-mediated cross-coupling reaction to afford aryl sulfides. An introduction to cross-coupling reactions and visible light photoredox catalysis is described in Chapter 1. Chapter 2 describes the reaction design and mechanistic studies with a focus on eliminating competitive reduction of the starting aryl iodide. Particular interest was taken in examination of Single Electron Transfer (SET) donors and solvents as these would be the most probable source of reduction in the reaction. A summary of this work and proposed future studies is delineated in Chapter 3. All procedures and results are present in Chapter 4.