Dissertation/Thesis Abstract

Synthesis of novel heteroaromatic structures via oxidative cyclization reactions
by Alshreimi, Abdullah Saad A., M.S., California State University, Fullerton, 2016, 161; 10145422
Abstract (Summary)

The development of new and convenient methodologies for the efficient synthesis of heteroaromatic ring systems remains an area of high interest. Oxidative cyclizations with radical or radical ion intermediates are potentially useful strategies to achieve these types of cyclizations. Previous studies from our group hypothesized that oxime ether radical ions would be susceptible to intramolecular nucleophilic attack whereas radicals would preferentially react with built-in radical traps. Our research has focused on evaluating different groups (aromatic rings, alkynes, and alkenes) in terms of their nucleophilicity or radical trap ability when built into the oxime derivative at a strategic location. In this thesis we report on an exploratory study dealing with obtaining an understanding for the reactivity of selected heteroatomic ring substrates linked to benzaldehyde oximes and oxime ethers and their potential cyclization patterns in terms of nucleophiles or radical traps. Therefore, we have prepared a series of furanyl, thiophenyl, and pyridinyl-substituted benzaldehyde oximes and oxime ethers and they were subjected to photooxidation processes in controlled conditions monitored by GC/MS and NMR for product formation. The results obtained suggest that under photoinduced electron transfer (PET) conditions oximes yielded the parent aldehyde, but did not undergo cyclization indicating that heteroaromatic rings do not behave as radical traps. Several oxime ethers (especially thiophenyl derivatives) were found to yield what is believed to be a cyclized product via nucleophilic attack by the heteroaromatic ring on the nitrogen of oxime ether.

Indexing (document details)
Advisor: de Lijser, Peter
Commitee: Orchard, Alexandra, Salzameda, Nicholas
School: California State University, Fullerton
Department: Chemistry
School Location: United States -- California
Source: MAI 55/06M(E), Masters Abstracts International
Source Type: DISSERTATION
Subjects: Organic chemistry
Keywords: Cyclization reactions, Heterocycles, Oximes, Photochemistry, Photosynthesis, Radical ions
Publication Number: 10145422
ISBN: 9781369009491
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