early transition metal  redox catalysis

early transition metals are Earth-abundant and generally nontoxic elements: excellent candidates for designing sustainable and green chemical reactions. however, engendering redox reactions with early metals is challenging because their high oxidation states are typically very stable. we are focused on understanding the fundamentals of early metal redox and applying this knowledge to develop practical and useful new catalytic methods. our signature finding in this area is centered around Ti-catalyzed nitrene transfer reactions, which proceed through a unique Ti(II)/Ti(IV) redox couple. this research is funded by the National Institutes of Health (R35GM119457) and the Alfred P. Sloan Foundation.

here are several recent reviews written by the group on this research area:

Ti-Catalyzed and -Mediated Oxidative Amination Reactions (Acc. Chem. Res. 2021, 54, 3476).

Multicomponent Syntheses of 5- and 6-Membered Heterocycles Using Groups 4-8 Transition Metal Catalysts (Chem. Sci. 2021, 12, 9574, Open Access)

Low Valent Early Transition Metals in Synthesis and Catalysis (Nature Reviews Chemistry 2019, 3, 15)


new strategies in polymerization catalysis

polyesters are an important class of polymers found in a range of materials applications, including clothing, sutures, and biodegradable tableware. we are interested in using organometallic catalysis to design new strategies (carbonylation, carboxylation) for making polyesters that are potentially biodegradable or biorenewable. an important focus of this work is on understanding the reaction kinetics of metal-catalyzed reactions with CO and CO2.  currently, we have several projects that are targeted at using alkene hydroesterification as a strategy to convert bio-based starting materials into value-added products, either small molecule or polymer. this research is funded by the US Department of Energy (DE-SC0020214), the NSF Center for Sustainable Polymers, and the MN Corn Growers' Association.

here are several key papers and reviews written by the group on this research area:

Sustainable Copolymer Synthesis from Carbon Dioxide and Butadiene (Chem. Rev. 2024)

Tunable and Recyclable Polyesters from CO2 and Butadiene (Nature Chemistry 2022ChemRxiv Open Access)

Development and Applications of Selective Hydroesterification Reactions (Trends in Chemistry 2021, 3, 469)