Date of Award
Bachelor of Science (B.S.) in Mathematics and University Honors
David R. Stuart
Chemical tests and reagents, Hypervalence (Theoretical chemistry), Iodine compounds, Organoiodine compounds
Diaryliodonium salts are promising novel reagents in arylation chemistry as they represent an efficient, inexpensive and non-toxic alternative to the most commonly used heavy-metal-based oxidants and organometallic catalysts. While the electrophilicity of these reagents has been widely accepted, few studies have made use of these new reagents as Lewis acids. In order to further the understanding of diaryliodonium salts, this work aims to quantify the Lewis acidity of a variety of aryl(2,4,6-trimethoxyphenyl)iodonium salts. To this end, the Guttmann-Beckett method was used in which NMR titrations of triethylphosphine oxide (TPO) and diaryliodonium salts were performed in deuterated acetonitrile. Nonlinear regression was then used to determine the association constants of each compound. The effect of counter anion identity was studied in phenyl(2,4,6-trimethoxyphenyl)iodonium salts and resulted in the following ranking, from lowest to highest acidity, based on counter anions: TFA < PF6< OTf < BF4. Lastly, para-tBu-phenyl(2,4,6-trimethoxyphenyl)iodonium tosylate yielded the lowest Lewis acidity measurement amongst all diaryliodonium salts studied.
Guillot, Florian H., "Quantitative Assessment of the Lewis Acidity of Diaryliodonium Salts" (2018). University Honors Theses. Paper 573.