Skip to main content
Skip to main menu

Slideshow

Comparative Study of Photochemically Generated Conjugated Ortho- and Para-Quinone Methide Reactivity

Ayesha Nisathar
Ayesha Nisathar
Graduate Student, Department of Chemistry
University of Georgia
Chemistry Building, Room 400
Organic Seminar

Isomeric ortho- and para-quinone methides, while possessing similar electronic structures, show very different properties. o-Quinone methides (oQM) are more reactive towards nucleophiles and undergo very fast and efficient inverse electron-demand-Diels-Alder (IEDDA) reaction with electron-rich alkenes. p-Quinone methide, while also acting as Michael acceptors, is not reactive in IEDDA.

The photochemical generation of o-naphthoquinone methide (o-NQM) from (3-hydroxynaphthalen-2-yl)methanol (o-NQMP) derivatives can be achieved with UV-A light  This reaction has been employed for the development of photolabile protecting groups (PPGs), procedure for the protein and peptide labeling, as well as reversible surface derivatization.    

In the present project, (3-hydroxynaphthalen-2-yl)(4-hydroxyphenyl)methanol (QMP 1) was designed to explore the feasibility of a novel approach to the generation of a  fluorescent dye. Interestingly, photo-dehydration of QMP 1 can produce both tautomers: o-naphthoquinone methide (o-NQM 1) and p-quinone methide (p-QM 1). Thus, the photoreactivity study of QMP 1 was carried to find out the predominant form of QM. Comparative analysis of the kinetics of QMP 1 reactions versus two structural analogs QMP 2, and QMP 3 will be presented. Photo-dehydration of QMP 2 can only form o-naphthoquinone methide analog (o-NQM 2), while QMP 3 is expected to produce only p-quinone methide analog (p-QM 3). Furthermore, applications of QMP analogs as fluorophores for imaging techniques will be provided.

applications of QMP analogs as fluorophores for imaging techniques

References

  1. Bai, W.J.; David, J. G.; Feng, Z. G.; Weaver, M. G.; Wu, K. L.; Pettus, T. R. R. The domestication of ortho-quinone methides. Acc. Chem. Res. 2014, 47, 3655-3664
  2.   Nachtsheim, B. J. Mild map to quinone methide. Nat. chem. 2020, 12, 326-328
  3. Arumugam, S.; Popik, V. V. Photochemical generation and the reactivity of o-naphthoquinone methides in aqueous solution. J. Am. Chem. Soc. 2009, 131, 11892-11899
  4. Kulikov, A.; Arumugam, S.; Popik, V. V. Photolabile protection of alcohols, phenols, and carboxylic acids with 3-hydroxy-2nanphathalenemethanol. J. Org. Chem. 2008, 73, 7611-7615
  5. Padwa, A.; Dehm, D.; Oine, T.; Lee, G. A. Competitive keto-enolate photochemistry in the 3-phenylisocoumaranone system. J. Am. Chem. Soc. 1975, 97, 1837-1845
  6. Dempsey, G. T.; Vaughan, J. C.; Chen, K. H.; Bates, M.; Zhuang, X. Evaluation of fluorophores for optimal performance in localization-based super-resolution imaging. Nature methods 2011, 8, 1027-1036

Support Us

We appreciate your financial support. Your gift is important to us and helps support critical opportunities for students and faculty alike, including lectures, travel support, and any number of educational events that augment the classroom experience. Click here to learn more about giving.

Every dollar given has a direct impact upon our students and faculty.

Got More Questions?

Undergraduate inquiries: chemreg@uga.edu 

Registration and credit transferschemreg@uga.edu

AP Credit, Section Changes, Overrides, Prerequisiteschemreg@uga.edu

Graduate inquiries: tharrop@uga.edu

Contact Us!

Assistant to the Department Head: Kelli Porterfield, 706-542-1919 

Main office phone: 706-542-2626 

Fax: 706-542-9454

Head of the Department: Prof. Gary Douberly