My research goals are to apply theoretical methods to interesting and important problems in organic chemistry.  An example of this is the use of quantum theory to understand the electronic and stereoelectronic contributions to the molecular orbitals participating in enediyne cyclizations (the Bergman cyclization).  This rearrangement is utilized by a large and important group of DNA binding and cleaving agents, some of which are clinically useful chemotherapeutic compounds.  It is hoped that our theoretical work can lead to the design of even more potent derivatives.  For example, several of these compounds use p- p stacking as a structural feature, and tweaking the nature of this interaction appears to significantly effect cyclization rates.

A large component of my research is concerned with orbital interaction through space.  When this interaction involves a cyclic array of electrons, the molecules belong to the “aromatic” class, in this case termed “homoaromatic”.  One recent concern has been the size limits to homoaromaticity, a subject which has not been investigated.  We find that previous qualitative expectations do not apply, and homoaromaticity in some systems extends to rather large rings.  Also, neutral bishomoaromaticity (double through space interaction) is possible, but end somewhere around an 18-membered ring.  We are also interested in replacing some briding ring carbons with other elements, like silicon.  Preliminary results show unusual effects.  A related study of 11-membered ring aromatic cations has uncovered the first example of Möbius antiaromaticity.

Selected Publications

Corminboeuf, C.; Schleyer, P. v. R.; Warner, P. "Are Antiaromatic Rings Stacked Face-to-Face Aromatic?" Org. Letters , 2007, 9, 326-266.

Warner, P., “Aromaticity and Möbius Antiaromaticity in Monocyclic [11]Annulenium Cations,” J. Org. Chem . (2006), 71 , 9271-9282.

Tantillo, Dean J.; Hoffmann, Roald; Houk, Kendall N.; Warner, Philip M.; Brown, Eric C.; Henze, Daven K.   Extended Barbaralanes: Sigmatropic Shiftamers or s -Polyacenes?    Journal of the American Chemical Society  2004,  126(13),  4256-4263.