Klumpp, Douglas A.
Ph.D. (Doctor of Philosophy)
Department of Chemistry and Biochemistry
The work outlined in this dissertation describes new synthetic methods in the synthesis of heterocyclic compounds mediated by superacid catalysis. Superacids are powerful reagents that enhance the reactivity of electrophiles, thereby opening the door to new reactive pathways with very weak nucleophiles. In this work, trifluoromethanesulfonic acid (triflic acid, CF3SO3H) is employed as a superacid catalyst to effect new transformations. These concepts are summarized in chapter 1. Chapter 2 describes a new acid-catalyzed cascade leading to the indolizidine ring system, which is present in a number of natural products. Experiments support a proposed mechanism involving vinylogous keto-enol tautomerization. The synthesis of the natural product ipalbidine is also described. In chapter 3, two common functional groups – carboxylic acids and isocyanates – are reacted in superacid to afford phthalimides and related aromatic imide products, which have several applications as both medicinal agents and thermally stable polymer materials. In chapter 4, highly charged carbocations are generated using triflic acid. The extreme charge density leads to migration of the positive charge to more distal sites on the molecule where reactions with nucleophiles may take place. Chapter 5 is a study separate from previous work on superacid catalysis. In this work, two common structures in drug design, amino acids and nitrogen heterocycles, are found to form adducts in multiple conditions. The reversibility of the reaction leading to these potentially valuable compounds is also examined.
Kennedy, Sean, "New Synthetic Methods Using Superelectrophiles" (2019). Graduate Research Theses & Dissertations. 7249.
Northern Illinois University
Rights Statement 2
NIU theses are protected by copyright. They may be viewed from Huskie Commons for any purpose, but reproduction or distribution in any format is prohibited without the written permission of the authors.