methodology & mechanism
Please click on the links above for a more detailed research description
Our research program is directed toward a) the total synthesis of pharmaceutically relevant molecules and natural products, b) the invention of new reactions and strategies in organic synthesis, and c) green chemistry.
Central to our research is
the development of efficient and environmentally benign reactions and
strategies. The Pharmaceutical Roundtable of the American
Chemical Society’s Green Chemistry Institute deemed cross-couplings
that avoid haloaromatics as their top aspirational reaction. In
collaboration with Professor
Mitch Smith, we are inventing such
reactions. Specifically, we are using catalytic C–H
activation/borylation, often combined with subsequent chemical events,
to generate pharmaceutically relevant building blocks for organic
synthesis. We were honored when the U.S. Environmental Protection
Agency recognized this chemistry with its 2008 Presidential Green
Chemistry Challenge Award.
Among the synthetic methods currently being investigated, we are particularly interested in the metal catalyzed chemistry of organostannanes, -silanes, and –boranes. A central aim of these studies is the use of such compounds in efficient and environmentally benign reactions and strategies. Currently, we are interested in minimizing the need for tin in various processes. Likewise, we are collaborating with Professor Milton “Mitch” Smith on the exploration of catalytic C–H activation/borylation of arenes as a means to avoid halogens during cross-coupling reactions. Wherever possible we also seek to “telescope” these plus other reactions into one-pot processes.
As we develop new synthetic schemes, the reactions are optimized and their mechanisms explored. For example, we are now in the midst of a study on the mechanism and kinetics of the Stille reaction. In another ongoing project, we are learning about stereochemical implications on the [1,4]-Wittig rearrangement.
Once these new reaction sequences become enabling technology for total synthesis, we apply them in the theater of natural product synthesis and towards the construction of other pharmaceutically relevant targets. Currently, we are looking to apply catalytic borylation chemistry to the total synthesis of autolytimycin. In another synthetic venture, we plan to make monocillin I with reactions that only employ catalytic amounts of tin. Similarly, our route to the potential anti-cancer natural product superstolide A involves the strategic in situ recycling of organotin reagents.