College of Arts & Sciences

A.L. Baumstark

Al Baumstark Professor and Chair Organic Chemistry B.A. (1970):  University of California, Riverside A.M. (1972) :  Harvard University Ph.D. (1974) :  Harvard University Postdoctoral Fellowship (1974-1976) :  Harvard University Dr. Al Baumstark Department of Chemistry Georgia State University P.O. Box 4098 Atlanta, Georgia 30302-4098 Phone:  404-413-5516 Lab Phone:  404-413-5517 Fax:  404-413-5505 Office:  518-B General Classroom Building Email:  chealb@langate.gsu.edu

Research in my group centers on the chemistry of oxygen-containing compounds with an emphasis on that of organic peroxides.  Currently, we are focused on the mechanisms of oxygen-atom transfer reactions of unusual hydroperoxides and peroxides, especially under mild conditions.  We have extended the frontiers in oxygen chemistry by synthesis and characterization of exotic, novel organic peroxides.  The ultimate goal of our investigations is to understand the limiting factors that control reactivity and selectivity in oxygen-containing systems.

We have developed the chemistry of cyclic and acyclic alpha-azo hydroperoxides and 3-hydroperoxy-1,2-dioxolanes.  These unusual hydroperoxides are of high reactivity and selectivity in electrophilic oxygen-atom transfer reactions.  We have discovered new synthetic routes to these reactive compounds.  Our work on the synthesis and thermolysis of 1,2-dioxetanes (4-membered cyclic peroxides) has been extremely productive.  We have studied the effects of substituents on the activation parameters of thermolysis.  We have measured the chemiexcitation yields for a large number of compounds.  These studies have provided insights into the mechanism of excited state formation in chemiluminescent and bioluminescent processes.

We have developed ¹⁷O NMR spectroscopy methods for the investigation of structure in oxygen-containing compounds. ¹⁷O NMR studies have been successful in predicting: (a) torsion angle relationships; (b) in-plane van der Waals repulsions; and (c) hydrogen-bonding phenomena.  The results of our studies have also been useful in applying ¹⁷O NMR methods to structural and labeling studies. 

We are actively investigating the oxygen-atom transfer chemistry of dioxiranes, 3-membered cyclic peroxides.  Our research on electrophilic epoxidation has led to postulation of a mechanism with a spiro transition state.  Current investigations center on epoxidation of electron-poor systems, computational modeling of epoxidation, and heteroatom oxidation.  We are also studying CH abstraction by dimethyldioxirane especially for oxidation of secondary alcohols and ethers.  Mechanistically, this feature of dioxirane chemistry is highly controversial.  Currently, dioxirane research is a major focus of our current research efforts.

Research lab supervised by Dr. Pedro Vasquez: phone: 404-413-5518; e-mail: chepcv@gsu.edu

Current Student Project Titles:

• Patricia Saponari, Ph.D. graduate student. Project: Dioxirane Oxidations of Selected Systems
• Joint research project with Professor Pamela Leggett-Robinson of Georgia Perimeter College. Project: Oxidation by Dimethyldioxirane

Representative Publications (of 124)

"Synthesis of 4,5-Dihydro-3,4,4,5,5-pentasubstituted-N-Tos-1H-pyrazoles,” P. Truong, G.D. Kennedy, P.C. Vasquez and A.L. Baumstark, Heterocyclic Comm. 2008, in press.

"The Reaction of Alkyl Benzyl Ethers with Dimethyldioxirane,” J.W. Jones, P.C. Vasquez and A.L. Baumstark, Heterocyclic Comm. 2008, 14, 11.

"N-Oxidation of 2-Substituted Pyridines and Quinolines by Dimethyldioxirane: Kinetics and Steric Effects," W.R. Winkeljohn, P. Leggett-Robinso, M.R. Peets, L. Strekowski, P.C. Vasquez and A.L. Baumstark, Heterocyclic Commun. 2007, 13, 25.

"Epoxidation of Substituted cis/trans-1,2-Dialkylalkenes by Dimethyldioxirane: Activation Parameters," B.S. Crow, W.R. Winkeljohn, A. Navarro-Eisensterin, E. Michelena-Baez, P.J. Franklin, P.C. Vasquez and A.L. Baumstark, E. J. Org. Chem. 2006, 20, 4642.

"¹⁷O NMR Spectroscopy of Heterocycles:  Substituent Effects in 3,5-Diarylisoxazoles and 3,5-Diarylisoxazolines," T. Yuzuri, S. Chandrasekaran, P.C. Vasquez and A.L. Baumstark, Heterocyclic Commun. 2006, 12, 7.

"Thermolysis of trans-3-Chloro-4,4,5-Trimethyl-3,5-Diphenyl-4,5-Dihydro-3H-Pyrazole," N. Desalegn, P.C. Vasquez, P.J. Franklin, G.D. Kennedy and A.L. Baumstark, Heterocyclic Commun. 2005 11, 375.
"Oxidation of Substituted Pyridines by Dimethyldioxirane: Kinetics and Solvent Effects," W.R. Winkeljohn, P.C. Vasquez, L. Strekowski and A.L. Baumstark, Tetrahedron Lett., 2004, 45, 8295.

Honors, Awards, etc.

1. Junior Faculty Teaching Award, College of Arts and Sciences, GSU, 1982
2. Camille and Henry Dreyfus Teacher-Scholar Award (1981-86)
3. Golden Key National Honor Society, GSU Distinguished Research Award (1987-88)
4. Advances in Oxygenated Processes, Alfons L. Baumstark, Series Editor, JAI Press Inc. Greenwich, Connecticut; 1988 - 1996.
5. Editorial Board - Heterocyclic Communications, 2003-present.