Molecular Recognition in Biological Systems and Bioinformatics

Organic synthesis; chemical synthesis; organometallic chemistry; new synthetic methods.

Organic Synthesis is Rewarding
Developing new reactions is exciting and one of the most enjoyable parts of academic research. One reaction we have recently developed is a cyclodiene ring synthesis based on tandem metathesis (eq 2). A ring is created through a series of metathesis reactions, all occurring in a single step. This efficient approach to ring synthesis has paved the way to new projects that use tandem reactions besides metathesis.

The reactions we develop are often inspired by complexity found in natural products. We like to apply our methods towards these structures or their complex substructures to illustrate the effectiveness and breadth of the chemistry (eq 3).

New Reactivity is Inspiring
In the course of “normal” research, we have discovered new reactions too. Cyclopropanation is a very rare reactivity mode for ruthenium carbenes (eq 4). Organometallic catalytic methods are extremely powerful for building molecular complexity. Depending on choice of catalyst, we can make two different products. We are now developing reactions that are inspired by this reactivity to make more complex ring systems.

Rapidly stopping enyne metathesis has shed insight into ruthenium carbene reactivity. The CO-promoted reaction gives a novel insertion into the N-heterocyclic carbene ligand. Based on this, we modified the additive to design a protocol to efficiently clean up metathesis reactions.

Catalysis and Organometallic Synthesis
Catalysis is difficult to study. Yet we weren’t satisfied with our level of understanding for catalytic enyne metathesis. We felt that improved knowledge would help us design new reactions. We started a collaborative project with Professor Keister to study the mechanism of enyne metathesis. We have developed a good working hypothesis, and plan to continue to study aspects of catalysis including catalyst decomposition and chelation. Future studies here will also require the synthesis of new ruthenium carbene complexes such as those containing novel cyclophane N-heterocyclic carbene ligands for enhanced selectivity in metathesis.

Anticancer agents, anti-angiogenic agents, small molecule probes (reagents for cell biology; not radioactive); also interested in diversity-oriented synthesis.

Chemical total synthesis; synthesis and purification of small organic molecules

http://www.chem.buffalo.edu/diver_publications.php