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Despite comprising a variety of bioactive compounds that can be utilized as effective synthetic precursors, the construction of halogenated arenes often relies on hazardous reagents and conditions that pose regioselectivity issues in complex systems. Halodecarboxylation using vanadium-dependent haloperoxidases (VHPOs) has emerged as a sustainable alternative for the synthesis of halogenated

Despite comprising a variety of bioactive compounds that can be utilized as effective synthetic precursors, the construction of halogenated arenes often relies on hazardous reagents and conditions that pose regioselectivity issues in complex systems. Halodecarboxylation using vanadium-dependent haloperoxidases (VHPOs) has emerged as a sustainable alternative for the synthesis of halogenated arenes. In the Biegasiewicz group, we recently discovered that VHPOs can furnish 3-bromooxindoles from 3-carboxyindoles through a decarboxylation event, followed by oxidation. While this tandem process was exciting, the intermediates of this process, 3- bromoindoles are independently valuable reagents, which necessitated further investigation. Herein we examine the biocatalytic access to bromoindoles for which we addressed the major challenge of undesired oxidation event. The first preventative approach acylated the indole nitrogen, resulting in 1-acetylindole-3-CO2H. This could then be subjected to optimized enzymatic bromination conditions to produce 1-acetyl-3-bromoindole in 98% yield with CiVCPO. The second preventative approach was to modify the reaction conditions, furnishing 1-methyl-3-bromoindole in 73% yield from 1-methylindole-3- CO2H with AmVBPO.

ContributorsLee, Hyung Ji (Author) / Biegasiewicz, Kyle (Thesis director) / Ackerman-Biegasiewicz, Laura (Committee member) / Seo, Dong-Kyun (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of Molecular Sciences (Contributor)
Created2023-05
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This thesis is about how Fe catalysts can be degraded using photocatalysis and how Fe catalysts can degrade small molecules in conjunction with light. The goal of this paper is to look further into more sustainable methods of organic chemistry. Many current organic chemistry practices involve the use of precious

This thesis is about how Fe catalysts can be degraded using photocatalysis and how Fe catalysts can degrade small molecules in conjunction with light. The goal of this paper is to look further into more sustainable methods of organic chemistry. Many current organic chemistry practices involve the use of precious metals. Iron is a more sustainable catalyst because it is abundant and inexpensive which is important for preserving the earth and making the organic chemistry more accessible. Along the same lines, light is a renewable energy source and has demonstrated its ability to aid in reactions. Overall, the goal of this paper is to explore the more sustainable alternatives to harsh and toxic organic chemistry practices through the use of Iron and light.

ContributorsBlenker, Grace (Author) / Ackerman-Biegasiewicz, Laura (Thesis director) / Redding, Kevin (Committee member) / Biegasiewicz, Kyle (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / School of International Letters and Cultures (Contributor)
Created2022-05
Description

The trifluoromethyl group is an essential chemical motif in pharmaceutical and agrochemical industries. The trifluoromethyl group has similar steric bulk to a methyl group, but exhibits strongly electron withdrawing properties. As a result, a trifluoromethyl group can provide a molecule with enhanced lipophilicity, bioavailability, and metabolic stability, which makes it

The trifluoromethyl group is an essential chemical motif in pharmaceutical and agrochemical industries. The trifluoromethyl group has similar steric bulk to a methyl group, but exhibits strongly electron withdrawing properties. As a result, a trifluoromethyl group can provide a molecule with enhanced lipophilicity, bioavailability, and metabolic stability, which makes it a commonly used tool to tune activity of agrochemicals and pharmaceutical candidates. There are many methods to generate a new trifluoromethyl moiety, but many of these methods rely on stoichiometric metal reagents or harsh reaction conditions. One strategy to install the trifluoromethyl group under benign conditions is with photoredox catalysis. In the field of photocatalysis, iron has emerged as an alternative for precious metals due to its low cost, earth-abundance, and environmentally benign nature. Methods of trifluoromethylation utilizing iron catalysis do exist, but they often rely on expensive CF3 precursors such as Togni’s Reagent and trifluoromethyl iodide. This thesis demonstrates a method using iron photocatalysis for decarboxylative trifluoromethylation of alkenes using trifluoroacetic acid. We have successfully enabled trifluoromethylation of select methoxy-substituted benzene derivatives as well as a number of alkenes, including those bearing sulfone and ketone groups.

ContributorsMclaughlin, Nathan (Author) / Ackerman, Laura (Thesis director) / Biegasiewicz, Kyle (Committee member) / Pillai, Smitha (Committee member) / Barrett, The Honors College (Contributor) / School of Life Sciences (Contributor) / Department of Psychology (Contributor)
Created2022-12