Faculty and Staff
Aaron K. Vannucci
|Title:||Assistant Professor / Inorganic
Catalysis / Materials / Organic / Organometallic
|Department:||Chemistry and Biochemistry
College of Arts and Sciences
Office: HZN1 015
B.A., 2004, College of Wooster
Ph.D., 2009, University of Arizona
We utilize transition metal catalysts and catalytic methodologies for small molecule syntheses with an emphasis on sustainable and/or renewable routes. Current projects include photoredox and electrochemical cross-coupling reactions, conversion of lignin biomass to renewable fuels, and photoelectrochemical production of molecular hydrogen.
Cross-Coupling: The long term goal of my research group is to advance photoredox catalysis for the development of new reaction mechanisms and synthesis of products that are inaccessible through thermal control, including C‑heteroatom coupling and C–H bond activation. Photoredox catalysis for organic synthesis relies on light absorbing molecules to convert visible light into chemical energy using single-electron transfer events. In particular, dual photoredox catalysis utilizes these single-electron transfers to activate a secondary transition metal catalyst for small molecule activation and bond forming reactions. Dual photoredox catalysis is currently revolutionizing cross-coupling catalysis with new methodologies for C–C bond-forming reactions. Furthermore, electro-organic chemistry is currently undergoing a renaissance of its own. The versatility of electro-organic chemistry is derived from its ability to apply precise electrical potentials to a reaction mixture, therefore, avoiding the problem of over reduction/oxidation that can be incurred during chemically driven redox reactions. We have use electrochemical methods to develope an “anion pool” method for the functionalization of heteroarene compounds.
Biomass Conversion: The lignocellulose component of biomass is typically comprised of three parts, cellulose (40-50% by weight), hemicellulose (25-35%) and lignin (15-20%). The lignin component of lignocellulose is typically treated as a waste component. However, the catalytic depolymerization of naturally occurring lignin results in a variety of oxygenated monomers that include, but are not limited to, phenol, benzyl alcohol, benzoic acid, benzaldehyde, and various ketones. The presence of these oxygenated substituents decreases the energy density of lignin, thus hindering the ability to use lignin effectively as a fuel. The high oxygen content also leads to instability and inherent difficulty to store oxygenates, which represents a major challenge in the ability to use lignin as a renewable chemical feedstock. Our group has focused on the design and synthesis of catalysts able to selectively deoxygenate lignin monomers without over-hydrogenation of the aromatic rings. First generation catalysts from our lab have exhibited excellent catalytic activity towards model lignin monomers, with the complete selectivity towards hydrodeoxygenation, even at room temperature. Our work now focuses on heterogenizing our selective molecular catalysts for easier incorporation of our catalysts into traditional industrial reaction vessels.
Key, R. J.; Vannucci, A. K. “Nickel Dual Photoredox Catalysis for the Synthesis of Aryl Amines” Organometallics, 2018 DOI: 10.1021/acs.organomet.8b00121.
DeLucia, N. A.; Das, N.; Vannucci, A. K. “Mild Synthesis of Silyl Ethers via Potassium Carbonate Catalyzed Reactions between Alcohols and Hydrosilanes” Org. Biomol. Chem. 2018, 16, 3415-3418. DOI: 10.1039/C8OB00464A.
Dissanayake, D. M. M. M.; Vannucci, A. K. “Transition-Metal-Free and Base-Free Electrosynthesis of 1H-Substituted Benzimidazoles” ACS Sustainable Chem. Eng. 2017, 6, 690-695. DOI: 10.1021/acssuschemeng.7b03029.
DeLucia, N. A.; Das, N.; Overa, S.; Paul, A.; Vannucci, A. K. “Low temperature selective hydrodeoxygenation of model lignin monomers from a homogeneous palladium catalyst” Catal. Today 2018, 302, 146-150. DOI: 10.1016/j.cattod.2017.05.050.
Paul, A.; Smith, M. D.; Vannucci, A. K. “Photoredox-Assisted Reductive Cross-Coupling: Mechanistic Insight into Catalytic Aryl-Alkyl Cross-Coupling” J. Org. Chem. 2017, 82, 1996-2003. DOI: 10.1021/acs.joc.6b02830.