TEMPLATE-DIRECTED PHOTOCHEMICAL CYCLOADDITION REACTIONS OF DIENOIC ACIDS AND STUDIES TOWARD FLUORANTHENE SYNTHESIS
Badar Munir
M.Sc. in Chemistry
Advisor: Dr. Yunus Emre Türkmen
Date: 29.12.2023
Time: 10:00
Place: Chemistry Meeting Room (1st floor – SB Building)
Abstract
Carbocyclic compounds are essential owing to their broad occurrence in natural products and pharmaceutically relevant compounds. Photochemical dimerization reactions exhibit great potential for the rapid synthesis of carbocyclic compounds. To circumvent the regio- and diastereoselectivity challenges associated with the photochemical dimerization reactions, we utilized the commercially available 1,8-dihydroxynapthalene (1,8-DHN) as a covalent-bonding template. After attachment, 1,8-DHN aligned the alkenes, fulfilling Schmidt’s criteria for topochemical reactions, and irradiation of template-bound diene gave products displaying high regio- and diastereoselectivity. It should be noted that our work represents the first example of selective homodimerization and heterodimerization reactions of 5-arylpentadienoic acids. Experiments to convert the divinylcyclobutane product to cyclooctadiene were unsuccessful due to troubles with the Cope rearrangement reaction.
In the second part, we aimed to develop a modular strategy for synthesizing substituted fluoranthenes. Suzuki-Miyaura borylation reaction was investigated to connect 1,8-diiodonaphthalene to a pyridazine ring as a dienophile for inverse electron-demand Diels-Alder reaction. Unfortunately, the reaction did not yield the desired conversion. To examine the possibility of the Ullmann coupling reaction, we performed studies with 1,8-diiodonapthalene and iodobenzene under Ullmann coupling conditions, which resulted in complex mixtures.
Keywords: Photochemical Dimerizations, Schmidt’s Topochemical Principles, Cope Rearrangement, Fluoranthenes, Inverse Electron-Demand Diels-Alder Reaction