DOI
https://doi.org/10.25772/FRTR-4Q20
Author ORCID Identifier
https://orcid.org/0000-0002-1275-9968
Defense Date
2020
Document Type
Dissertation
Degree Name
Doctor of Philosophy
Department
Chemistry
First Advisor
Scott Gronert
Abstract
C-H activation is considered the “holy grail” of chemistry. Remote, selective C-H activation has many applications such as modifying precursors, adding complexity to molecules, and modifying pre- existing structures in a reduced number of steps. Previous work by Swift and Gronert identified an iridium(III) phenanthroline complex that can activate C-H bonds of cyclohexane. The objective of this dissertation is to study the mechanism and regioselectivity of this complex in common precursors, namely 1-butanol, 1-methoxybutane and butyl acetate.
The studies were carried out in the gas phase on a modified mass spectrometer. Selectively deuterated alcohol, ether and ester were used to determine the site of activation. The studies showed that the iridium phenanthroline complex can activate the gamma and delta positions in 1-butanol, selectively activate the gamma position (~96%) in 1-methoxybutane and the alpha carbon in butyl acetate.
Studies were also carried out to determine the effect of the ligand on the regioselectivity of the complex. A range of iridium complexes was either purchased or synthesized to study the impact of sterics, electronic effects, the flexibility of the ligand, the effect of the chelating atom in the neutral ligand and the effect of the anionic ligand on the regioselectivity of C-H activation of the model alcohol, ether, and ester. The studies showed that there were only subtle impacts on the regioselectivity of the C-H activation in these substrates. However, the overall reactivities of the complexes were found to be impacted by the nature of the ligand.
Rights
© The Author
Is Part Of
VCU University Archives
Is Part Of
VCU Theses and Dissertations
Date of Submission
12-3-2020