Project Director

Yang, Wang-Yong, 1974-

Department Examiner

Angle, Steven; David, Samuel Satyajit

Department

Dept. of Chemistry and Physics

Publisher

University of Tennessee at Chattanooga

Place of Publication

Chattanooga (Tenn.)

Abstract

The photo-dehydro-Diels–Alder (PDDA) reaction is a useful method for the construction of substituted naphthalene derivatives from acyclic precursors. While intramolecular variants of this transformation are well established, intermolecular PDDA reactions remain rare due to challenges associated with controlling reactivity under photochemical conditions. Previous studies suggest that electron-withdrawing substituents can promote intermolecular cycloaddition by increasing alkyne polarization and stabilizing reactive intermediates. In this work, the effect of enhanced electron-withdrawing character on intermolecular PDDA reactivity was investigated through the incorporation of a 2,3,5,6-tetrafluoropyridinyl substituent. Corresponding alkyne substrates were synthesized and subjected to photochemical conditions, resulting in the formation of 1,2,3-triarylnaphthalene products. The products were successfully isolated and characterized, with X-ray crystallography confirming the formation of the expected aromatic framework and providing insight into regiochemical outcomes. These results demonstrate that strongly electron-deficient heteroaryl substituents can facilitate intermolecular PDDA reactivity. This work highlights the role of electronic modulation in promoting photochemical cycloadditions and provides a foundation for the development of new intermolecular PDDA systems.

Acknowledgments

URACE SEARCH Award I would like to first and foremost recognize my thesis director, Dr. Yang. Dr. Yang has allowed me to work in his lab and mentored me for going on over years as of writing this. Without his constant insistence that I needed to think like a researcher to be a researcher, I do not think that I would have gone as deep into the research world as I plan to. I am also extremely grateful to the professors around me in both my classes and the research lab, most specifically Dr. Lee and Dr. Pienkos. They have always been available to discuss lab work, to share their chemistry knowledge, or simply just to laugh about how the NMR machine looked like a UFO when the power went out on campus. Their insights and guidance have been invaluable in this process, despite their absence in an official capacity. Of course, this process is impossible without the members of my thesis committee, Dr. Angle and Dr. David. Both individuals have been a pleasure to work with, and I am incredibly grateful that they volunteered their time to be on my committee. Dr. Angle’s insights into both 2D NMR and NOESY/HOESY NMR were invaluable, and he was always a pleasure to talk chemistry with. Dr. David was extremely willing to join my committee, despite him being a brand-new member of the department, and I am very grateful for the comments and recommendations that he has provided. Thanks to Dr. Barbee for teaching me how to and letting me use her Schlenk line and argon. We couldn’t have explored the failed avenue of the metal-catalyzed reaction without you. It is also crucial to recognize the contributions of individuals no longer at UTC, but made this project achievable – Ethan Eakins and Lukas Wise. Both contributed substantially to the preparation of many of the acetylene monomers, as well as reaction optimization. To my friends and family who have been there for me on both the good and bad days, I am eternally grateful. I may not always know how to explain my project to some of you, but your support and genuine enthusiasm were always a pleasure. Thank you, mom and dad, for always supporting my dreams and aspirations, whether emotionally or financially. You have gotten me through some dark days, and I can only hope to repay the favor one day.

Degree

B. S.; An honors thesis submitted to the faculty of the University of Tennessee at Chattanooga in partial fulfillment of the requirements of the degree of Bachelor of Science.

Date

5-2026

Subject

Diels-Alder reaction; Naphthalene--Synthesis; Photochemistry

Keyword

organic chemistry; dehydro-diels-alder; intermolecular; photochemistry; novel

Discipline

Organic Chemistry

Document Type

Theses

Extent

i, 64 leaves

DCMI Type

Text

Language

English

Rights

http://rightsstatements.org/vocab/InC/1.0/

License

http://creativecommons.org/licenses/by/4.0/

Download

Share

COinS