Semester

Summer

Date of Graduation

2019

Document Type

Dissertation

Degree Type

PhD

College

Eberly College of Arts and Sciences

Department

Chemistry

Committee Chair

Brian V. Popp

Committee Co-Chair

Jessica M. Hoover

Committee Member

Jessica M. Hoover

Committee Member

Bjorn Soderberg

Committee Member

Carsten Milsmann

Committee Member

Tatiana Trejos

Abstract

Hetero(element) carboxylation is an appealing transformation that involves the installation of CO2 and another hetero(element) in one step. This transition metal-catalyzed one-pot synthesis provides a route to achieve highly functionalized carboxylic acid products with an abundant and cheap C1 feedstock. This difunctionalization also avoids the use of reactive metal hydride species, which is a prominent limitation of hydrocarboxylation chemistry. A copper-catalyzed regioselective boracarboxylation of vinyl arenes has been developed to access pharmaceutically relevant β-boryl-α-aryl propionic acid products. One drawback of this reaction is the necessity for high catalyst loading to achieve catalytic turnover. To circumvent this issue, the reduction of catalyst loading by addition of a secondary phosphine ligand was examined to access previously reported substrates and an expanded scope for this transformation. Trends in reactivity and preliminary experiments to determine the role of exogenous phosphine in the catalytic system will be described. The synthetic utility of the boracarboxylated products was investigated through a contemporary carbon-boron bond transformation to afford fluorinated products. The reactivity and scope of a deboronofluorination pathway will be presented, along with mechanistic investigation. The synthetic utility of boracarboxylated products to form new carbon-carbon bonds through cross-coupling afforded 2,3-diarylpropionic acids. This synthetic pathway will allow for chemoselectivity that is not observed through traditional pathways, such as the hydrocarboxylation of stilbenes.

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