Date of Submission

Spring 2020

Academic Program

Chemistry

Project Advisor 1

Emily McLaughlin

Abstract/Artist's Statement

Cyclobutane rings are important structural features in many biological and artificial molecules but the high ring strain associated to the 4-membered ring makes their preparation difficult. [2 + 2] Photocycloaddition is the most frequently used methodology to access these carbocyclic products, which are usually thermally inaccessible according to the Woodward-Hoffmann symmetry rules. The vast majority of [2 + 2] photocycloaddition reactions involve enone-alkene cycloaddition which is conveniently achieved through direct excitation or sensitization by irradiation by ultraviolet (UV) light. However, using UV light has several drawbacks including the production of undesired side products and decomposition of photosensitive functional groups.

This work focuses on the investigation of a [2 + 2] cycloaddition methodology mediated by lower energy, visible light as an alternative to UV light. More specifically, we develop the synthesis of a novel vinylogous amide to be used as an intermolecular photocycloaddition coupling partner, catalyzed by an iridium polypyridyl transition metal catalyst. The reaction is believed to proceed via a triplet energy transfer from the metal catalyst to our photosubstrate and we anticipate at least modest regio- and stereoselectivity in a system where three new stereocenters are formed in one synthetic step.

Open Access Agreement

On-Campus only

Creative Commons License

Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

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