"Hydrogen... a light, colorless, odorless gas, which, given enough time, turns into people"

- Ted Harrison, British Astronomer/Cosmologist


UC Davis Chemistry





Professor, UC Davis, 2011-present

Associate Professor, UC Davis, 2008-2011

Assistant Professor, UC Davis, 2003-2008

Postdoctoral Associate, Cornell University, 2000-2003

with Roald Hoffmann

PhD, Chemistry, UCLA, 1995-2000

with Ken Houk

AB, Chemistry, Harvard University, 1991-1995

Born (1973) and raised in Quincy, Massachusetts, USA


Detailed CV

LinkedIn Profile

Google Scholar Profile

Chemical Family Tree


Our research is driven by intriguing mechanistic questions and spans many areas of organic chemistry. These include enzyme catalyzed reactions, reactive intermediate promoted polycyclization (RIPP) reactions, catalyst design, physical organometallic chemistry, carbocation structures and rearrangements, pericyclic reactions, regio- and stereoselectivity of synthetically useful reactions, aromaticity, and computer-aided design of enzyme inhibitors and nucleobase analogs.

Our group is particularly interested in understanding the mechanisms of various cascade polycyclization reactions used by Nature and by chemists to synthesize complex natural products such as those shown below.

We are also exploring the concept of "transition state complexation" as an approach towards designing new catalysts for otherwise unfavorable organic reactions, such as formally "forbidden" pericyclic reactions.

Our primary tool for tackling these mechanistic problems is quantum chemistry. We apply various methods - e.g., density functional theory (DFT) - to compute structures, relative energies, activation barriers, NMR and IR spectra, isotope effects, and solvation effects. One of our favorite approaches involves using "theozymes" - theoretical enzymes - to design biological and non-biological catalysts. We also make use of ab initio direct dynamics trajectory calculations to explore nonstatistical dynamic effects on reactivity.

Using these methods, we like to make structural and reactivity predictions. Then we like to see if these predictions are born out in the laboratory.

Research Information

Research Projects


Cover Gallery


Grant Support

Computational Methods

CheShiReCCat Chemical Shift/Coupling Constant Scaling Factor Website


R Bryan Miller Symposium

Accelerating Reaction Discovery TSRC Workshop

Reaction Mechanisms Conference ('14)


SYLICCO Conference

Walking in the Woods with Chemistry at the UCD Arboretum


Department of Chemistry

UCD Chemical Biology Program (CBP)

Graduate Group in Education

Agricultural and Environmental Chemistry Graduate Group

Accessible Science

ACS Sacramento Section

Alliance for Diversity in Science and Engineering (UCD Chapter)


Dean has taught both graduate and undergraduate chemistry classes for both chemistry and non-chemistry audiences. These classes have ranged in size from less than ten to over three hundred students. For more details, follow the links below.


Dean's Teaching Experience and Awards

Dean's Teaching Philosophy


Taiwan Quarter Abroad Program

Pharmaceutical Chemistry Undergraduate Program

Making Computational Chemistry Accessible to Blind Students


Current Group Members

The Group in Action

Group Alumni

Group News

Awards Earned by Group Members

Group Data

Tour of the Labs


Symmetry, science, and life

Representation and presentation

Old books and physical organic history

Organic models and modelers


Chemical wordplay

Logic and perspective

Some photos

Snow and snowflakes

Green is good

Beyond chemistry - interested in virtual volunteering?

Daddy's little chemist

Some acknowledgments


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Contact Dean with any questions, comments, or suggestions...