Date of Graduation
Eberly College of Arts and Sciences
Linear alpha olefins (LAOs) are important building blocks in the production of linear low-density polyethylene, a plastic used in products such as shrink wraps, plastic bags, tubing, plasticizers, among others. Commercial methods for generating LAOs utilize ethylene oligomerization, but this method is reliant on fossil fuels and leads to unselective product formation. Synthesis of LAOs from renewable resources, namely carboxylic acids, by decarbonylative dehydration strategies has been well studied, however, this method has inherent drawbacks rooted in the formation of internal olefin side-products through isomerization pathways. With the goal of avoiding internal isomerization, this thesis explores a dehydrogenative decarboxylation strategy for conversion of carboxylic acids to alpha-olefins.
The first chapter outlines traditional methods for linear alpha olefin generation and discusses well-developed methods for the use of carboxylic acids as feedstocks. The second chapter details the development of a new copper-catalyzed dehydrogenative decarboxylation reaction of carboxylic acids to styrenes. A series of mechanistic experiments indicate that the reaction proceeds via benzylic deprotonation and subsequent radical decarboxylation; a pathway that is distinct from mechanisms implicated in related decarboxylative elimination reactions. Chapter 3 explores the selective dehydrogenation of carboxylic acids and methyl esters to cinnamic acids and alpha,beta-unsaturated esters. This chapter outlines a broad survey of reactivity, highlighting the role of the oxidant in dictating product formation, styrene via decarboxylation and alpha,beta-unsaturated carbonyl compounds through dehydrogenation. The final chapter describes exploration of reaction conditions for the copper-catalyzed decarboxylation of substituted cinnamic acids. The chapter also describes our ongoing efforts towards identifying the key reaction parameters necessary for efficient product formation.
Stanton, Michael P., "Copper-Catalyzed Dehydrogenative Decarboxylation Reactions of Carboxylic Acids to Alkenes" (2023). Graduate Theses, Dissertations, and Problem Reports. 11990.