Texas Tech University

Dr. David M. Birney

Title: Professor

Education: Ph.D., Yale University, 1987; Postdoctoral Study, University of California, Los Angeles; Guest Professor, ETH - Zurich, Fall 2008

Research Area: Physical Organic & Mechanistic Chemistry

Office: Chemistry 232-C

Phone: 806-834-7167

Fax: 806-742-1289

Email: david.birney@ttu.edu
Research Group
Chem 2303 (2013)

Principal Research Interests


In our group, we use high level ab initio and density functional calculations to provide fundamental insights into two classes of reactions, pseudopericyclic and pericyclic. We then design and conduct experiments to test the predictions of these calculations. The synergy between theory and experiment has provided insights and research directions that would not be possible from either alone.

Pseudopericyclic Reactions

The "conventional wisdom" of the orbital symmetry rules tells an organic chemist what to expect from a pericyclic reaction. Pseudopericyclic reactions violate all of these expectations of a pericyclic reaction, yet strictly speaking they are orbital symmetry allowed. The fundamental difference between the two is that in a pseudopericyclic reaction, there is not orbital overlap around the ring of breaking and forming bonds. This allows their transition states to have a planar geometry, and, often, very low activation barriers.The difference between a planar pseudopericyclic transition state and a non-planar pseudopericyclic one is illustrated in two animations of these reaction pathways. The dramatic differences in geometries between them are summarized below.

Familiar Pericyclic Reactions

Cyclic orbital overlap

Non-planar, non-least motion transition states

Pericyclic reactions can be allowed or forbidden, depending on the number of electrons

Concerted pericyclic reactions have lower barriers than stepwise alternatives. Barriers are due to enforced electron-electron repulsion

Novel Pseudopericyclic Predictions

Disconnections in orbital overlap

Planar (or nearly planar) transition states

All pseudopericyclic reactions are allowed; there are no anti-aromatic transition states

Pseudopericyclic reactions can have lower barriers than pericyclic alternative. There is no enforced electron-electron repulsion

Representative Publications


"Competitive Pseudopericyclic [3,3]- and [3,5]-Sigmatropic Rearrangments of Trichloroacetimidates", Shikha Sharma, Trideep Rajale, Daniel K. Unruh, David M. Birney, J. Org. Chem. 2015, 80, pp 11734–11743, invited contribution, special issue on the Woodward-Hoffmann rules. 10.1021/acs.joc.5b01355
"An Efficient Synthesis of 4-Substituted Coumarin Derivatives via a Palladium-catalyzed Suzuki Cross-coupling Reaction." Trideep Rajale, Shikha Sharma, Daniel A. Stroud, Daniel K. Unruh, Emily Miaou, Kimberly Lai and David M. Birney, Tetrahedron Lett. 2014, 55, 6627-6630, 10.1016/j.tetlet.2014.10.078
"Experimental and Computational Studies on the [3,3]- and [3,5]-Sigmatropic Rearrangement of Acetoxycyclohexadienones; a Non-ionic Mechanism for Acyl Migration." Shikha Sharma, Trideep Rajale, David B. Cordes, Fernando Hung-Low, David M. Birney, J. Am. Chem. Soc. 2013, 135, 14438-14447, 10.1021/ja4077364
"Optimizing Esterification of Safflower, Cottonseed, Castor and Used Cottonseed Oils." Tina P. Thomas, David M. Birney, Dick L. Auld, Industrial Crops and Products, 2013, 41, 102-106.
"The Potential Energy Surface for (Retro-)Cyclopropanation – Metathesis with a Cationic Gold Complex", Alexey Fedorov, Laurent Batiste, Andreas Bach, David M. Birney, Peter Chen, J. Am. Chem. Soc. 2011133, 12162–12171, 10.1021/ja2041699
"Theory, Experiment and Unusual Features of Potential Energy Surfaces of Pericyclic and Pseudopericyclic Reactions with Sequential Transition Structures" David Martin Birney, Curr. Org. Chem. 2010, 14, 1658-1668, invited contribution to special issue on Molecular Simulations in Organic Chemistry, 10.2174/138527210793563260
"Cyclohexane Isomerization. Unimolecular Dynamics Of The Twist-Boat Intermediate" Khatuna Kakhiani, Upakarasamy Lourderaj, Wenfang Hu, David Birney, and William L. Hase J. Phys. Chem. A 2009, 113, 4570–4580, 10.1021/jp811208g
"Multiphoton Infrared Initiated Thermal Reactions of Esters: Pseudopericyclic Eight-Centered cis-Elimination" Hua Ji, Li Li, Xiaolian Xu, Sihyun Ham, Loubna A. Hammad, David M. Birney, J. Am. Chem. Soc. 2009, 131, 528-537, 10.1021/ja804812c

Contact

Department of Chemistry & Biochemistry