Tom R. Pettus

Professor

Office Hours

Tuesday (2-3pm, Chem 2120)
Thursday (2-3pm, Chem 2120)

Contact Phone

(805) 277-7274

Office Location

Chem 2120

Specialization

Bio

Dr. Pettus worked as an undergraduate researcher in 1989 with Professor Tomás Hudlicky at VPI and subsequently obtained his Ph. D. degree in 1996 at the University of Rochester after working with Professor R. H. Schlessinger as a ACS organic graduate fellow. Following postgraduate work as an NSF Postdoctoral Fellow at Columbia University with Professor S. J. Danishefsky, Dr. Pettus joined the UCSB Chemistry Department in 1998. Dr. Pettus was awarded a Research Innovation Award from Research Corporation and in 2001 and NSF-Career Grant. His group currently has six graduate students and two postdocs.

Research

Research Group Website: http://web.chem.ucsb.edu/~pettus/Pettus_Group/

Current Research

Our research program pursues new methods and strategies for constructing architecturally complex tetramic acid derivatives.  Chiral tetramic acids and their derivatives are significant, because this structural motif is embedded in a multitude of natural products that display a dizzying array of biological activities.  Their uses include potent antimicrobial therapies, as well as noteworthy applications as antiviral, and antifungal treatments.  Several tetramic acids demonstrate insecticide and cytotoxic properties, as well as an ability to perturb quorum sensing and inhibit enzymes.  Given their natural prevalence, biological importance, and apparent simplicity, it was surprising for us to learn that general synthetic methods leading to their enantioselective construction are lacking.  Most synthetic chemists choose to build or buy the stereocenters, and then construct the fragile heterocyclic ring system of the chiral tetramic acid near then end of their effort.  Our goal is to develop new strategies and methods to improve the efficiency for building current and ever more challenging architectures containing this heterocyclic motif.  The total synthesis of the natural product tetrapetalone A presently serves as the backdrop and provides motivations for our future plans.  Previous synthetic efforts aimed at the tetrapetalones, as well as current omissions in the chemical literature have identified and illuminated a clear need for the development of new methods to assemble this and complex chiral tetramic acid (TA) architectures in an enantioselective manner.  We propose to examine a new vinylation reagent, along with three novel enantioselective methods aimed at C-C bond formation, as well as the enantioselective synthesis tetrapetalone-A itself to expand current chemic knowledge surrounding the tetramic acid motif.

Undergraduate are expected to work for at least two summers and complete enough work for a publication. Contact Dr. Pettus if you are interested. Graduate students typically begin with a synthetic methods project before moving on to a natural product synthesis by their 2nd or 3rd year. Most graduate students finish their Ph.D. within five years earning 4-5 publications and finding employment in the pharmaceutical industry.

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Publications

Selected Research Publications

Bai, W-J.; Jackson, S. K.; Pettus, T. R. R. 2022 "Ch 6: Tetrapealones ruminations, trials and tribulations" ed. Harmata, M. Strategies and Tactics in Organic Synthesis, Elsevier (v. 15) 211-246. ISBN 978-0-12-822212-6.
 
Chen, KC; Wong, Y.F.; Pettus, T. R. R. "Nucleophilic Imines and Electrophilic o-Quinone Methides, a Three-Component Assembly of Assorted 3,4-Dihydro-2H-1,3-benzoxazines" Organic Letters  2019, 21, 7746-7749. DOI: 10.1021/acs.orglett.9b02655
 
Feng, Z-G.; Burnett, G. L.; Pettus, T. R. R.“A Biomimetic Synthesis of des-Hydroxy Paecilospirone”  Synlett, 2018, 29, 1517-1519.  DOI: 10.1055/s-0036-1592001
 
Bai, W. J.; Pettus, T. R. R.“Synthetic Studies toward the Tetrapetalones: Diastereoselective Construction of a Putative Intermediate”  Org. Lett. 2018, 20, 901-904. DOI: 10.1021/acs.orglett.7b03500

Feng, Z-G.; Bai, W. J.; Pettus, T. R. R.“Unified Total Syntheses of Medicarpin, Sophoracarpan A, and Kushecarpin A with Some Structural Revisions*”  Angew. Chemie. 2015, 54, 1864-1867. https://doi.org/10.1002/anie.201408910