Chemistry and Biochemistry

Research

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A multidisciplinary approach to science can enable advances not only at the interface of two fields, but also within strictly disciplinary research. This capacity derives from an acquired understanding of the scientific approach, methods, and techniques used in other disciplines to solve problems.  I intend to establish a research program that employs tools and techniques from other disciplines to solve difficult problems in organic synthesis and catalysis.  With the experience and understanding gained through these early investigations, my laboratory will be poised to answer important questions at the interface of chemistry and other fields.  Students in my group will have the opportunity to work at the interfaces of inorganic and organic synthesis, polymer science and catalysis, and structural biology and catalysis.

Polymer-Supported Nanoparticle Catalysts

The design and synthesis of metal-based nanostructured materials has emerged as a major research direction in several areas including optics and electronics, sensing, medicine, and catalysis.  For these applications, the properties of a transition metal nanomaterial can be varied by changing the size (surface area), molecular structure, and shape of the nanoparticle itself. An alternative strategy for optimizing the physical, optical, or reactive properties of a nanoparticle is by designing and modifying the structure of the supporting matrix or surface-bound ligands. Our research program seeks to design, synthesize, and utilize polymer-supported transition metal nanoparticles for catalytic applications where the nanoparticle reactivity and selectivity can be controlled by modification of the polymer support structure. Early published results from our laboratory have confirmed that the electronic structure of the supporting polymer can have a significant impact on catalytic activity in nitroarene reduction reactions.  The main goals of this project are to 1.  quantify the nature and strength of the polymer-nanoparticle interaction in order to rationally design nanoparticles with unique reactivity; and 2. Use these nanoparticle catalysts to develop highly efficient organic transformations.

Electrophilic Catalysis with Heterobimetallic Complexes

I am broadly interested in new strategies to tune the reactivity and selectivity of transition metal catalysts.  Incorporation of an electron-releasing or electron-withdrawing transition metal “ligand” into a bimetallic complex can greatly influence the reactivity of the active metal center.  In this manner, enhanced electrophilic and nucleophilic catalysts can be generated through incorporation of an “inorganic ligand,” while maintaining supporting ligands capable of inducing the appropriate selectivity for the desired reaction.  The main goal of this project is to understand and utilize heterobimetallic interactions to generate highly active electrophilic transition metal catalysts for organic synthesis.  This project will seek to employ heterobimetallic catalysts for the development of olefin activation and C–H functionalization reactions.

α-Helical Peptide Scaffolds as Modular, Tunable, Enzyme-Like Catalysts for Multistep Synthesis

The enormous breadth of chemical reactions performed in biological systems can be attributed to nature’s ability to construct highly ordered arrangements of catalytic functional groups, or enzyme active sites.  In addition, many organisms have evolved the ability to assemble polyketide synthases (PKSs), or multienzyme complexes that are capable of performing multistep synthesis in a linear fashion.  Chemists have tried to mimic nature’s efficiency by constructing multifunctional catalysts or by designing multicomponent reactions or multi-catalyst systems.  What is still lacking is a system that mimics nature’s ability to form structurally precise collections of functional groups (active sites) in a modular fashion that enables not only catalysis but also multistep synthesis.  This project will investigate the use of short helical peptides to display catalytic functional groups in a stereocontrolled fashion to achieve enzyme-like catalysis.  This template approach will provide a new strategy for catalyst design and optimization that takes advantage of substrate preorganization and proximity to improve catalytic activity.  The helical scaffold will also make possible the design and construction of multifunctional catalysts capable of performing multistep synthetic processes.

Research interests include: Organic synthesis, catalysis, natural product total synthesis, inorganic synthesis, polymer chemistry, biocatalysis.