Sustainable Approaches to Photo-, Thermo-, and Electro-Chemical Reactions of Amines

In recent years, sustainable routes for chemical synthesis have garnered renewed interest. As the world continues to fight pollution and rising costs, it is imperative that new routes of synthesis that continuously fight the issues of pollution and waste are discovered, defined and explored. While traditional synthesis routes that require energy input typically require the burning of fossil fuels to produce heat, the amount of resources that go into the production of these fossil fuels and the sequestration of its waste to minimize its impact on the carbon footprint is enormous. Furthermore, sustainable chemistry research aims to decrease and minimize waste produced by traditional synthesis methods by increasing selectivity, removing the utilization of halogenated and/or volatile solvents and decreasing waste produced by harmful and/or expensive byproducts of these reactions. The second chapter of this dissertation details the photochemical oxidation of aniline derivatives for the synthesis of azobenzene molecules. This research has provided a route for azobenzene synthesis that obtains unprecedented selectivity while utilizing light as a renewable energy source. Furthermore, this reaction scheme replaces traditional sacrificial electron acceptors with oxygen showing that the only waste produced is hydrogen peroxide. Throughout this chapter, the mechanism is explored to show the unique radical coupling mechanism and that oxygen is not involved in the oxidation of the aniline products. Carbon-nitrogen bonds are utilized for many pharmaceutical and material purposes. The third chapter in this dissertation explores the relationship between nitrogen heterocycle’s pKa and how the electrochemical generation of their anions provide unique reactivity and selectivity for the purpose of synthesizing new carbon-nitrogen bonds. It is also explained throughout this chapter the relationship between the electrolyte and anion reactivity as well as the electronic properties of the electrophile and their effect on the success of the nucleophilic substitution. The last project discussed herein is the development of an understanding in the benzidine rearrangement method. This method of synthesizing aromatic carbon-carbon bonds has been of interest in the past due to its unique ability to form bonds without the utilization of expensive transition metal catalysts. The mechanism by which this rearrangement occurs is hypothesized to be via an intramolecular mechanism. The electronic effects and functionality of a wide range of substituents is explored seeking to understand how these factors affect the overall success of benzidine rearrangement