Organic SynthesisOrganic synthesis
. Organic synthesis is the enabling science for many new technologies. We are developing new methods and strategies for the formation of carbon-carbon bonds. Projects include the use of pericyclic reactions to achieve control of stereochemistry, regiochemistry, and absolute configuration of complex polycyclic skeletons. Novel bridged bicyclics, such as anti-Bredt olefins, frequently serve as key intermediates. Synthetic targets include biologically important natural products that include N-methyl welwistatin and (-)-stenine. We are also developing new bis-Lewis acids as potent catalysts for a variety of synthetic transformations. Polymer Chemistry - Materials Science Molecular Imprinting
- Molecular imprinting is a general protocol for creating receptor and/or catalytic sites in cross-linked network polymers. We are using molecular imprinting to prepare materials that function as synthetic biological receptors and as artificial cell membranes that mediate the selective transport of complex organic molecules. Imprinted polymers are being developed for their use as surrogates for drug receptors, catalysts, separation media and as the recognition element for chemical sensors. Additional topics include microfabrication of imprinted polymers and the design of imprinted polymers for binding small peptides. The program interfaces polymer and synthetic organic chemistry, as well as materials science and bioorganic chemistry.Polymer and Material Synthesis
- Carbon backbone polymers are the worlds most widely used synthetic materials. We are developing new reactions for the synthesis of carbon backbone polymers. Unlike the traditional methods of polymer synthesis that involve the polymerization of olefins, our method assembles the carbon backbone one carbon at a time
. These new living polymerization reactions are being used to synthesize functional carbon backbone polymers, and to create novel polymer topologies such as huge macrocyclic rings.Material Synthesis
- Bridged polysilsesquioxanes are hybrid organic-inorganic materials that are prepared by sol-gel polymerization from monomers that contain a variable organic bridging group and an inorganic oxide precursor. The resulting xerogels and aerogels have physical and mechanical properties that are strongly influenced by the organic bridging group. We are interested in studying the relationship between bulk properties of the material and the molecular building block. Physical properties such as porosity, thermal stability, refractive index, optical clarity, chemical resistance, hydrophobicity, and dielectric constant can be controlled at the molecular level of design. The materials are being evaluated in such diverse applications as "super absorbents" for wastewater remediation, and as processable materials for fabrication of non-linear optical devices.