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- Creators: School of Life Sciences
- Creators: Haydn, Joseph, 1732-1809
In the face of deep disconnection and chaotic crises throughout our planet, I have identified five invitations for foundational actions and ways of living, that can lead to us deepening our connection with ourselves and with the Earth in individualized ways, while cultivating harmony on our shared world. These are; to listen, to express, to envision, to reciprocate, and to dance. An open mind and heart will make them most effective.
Synthetic plastics are ubiquitously used in a broad range of applications, including food and drink packaging. Plastics often contain chemical additives, including bisphenols, phthalates, and terephthalic acid, which can degrade under thermal stress. The environmental presence of these chemicals is cause for public concern, especially in consumer products that utilize plastic packaging, as many have been identified as endocrine disruptors. This study sought to determine exposure to phthalates, bisphenols, and terephthalic acid by quantifying a broad spectrum of these analytes within three bottled water brands at varying temperature exposure levels using the combination of solid phase extraction followed by isotope dilution liquid chromatography-tandem mass spectrometry. Monobenzyl phthalate was detected in two of the three brands after bottles were heated to ~100 °C, ranging from 98 – 107 ng/L, and bisphenol A was detected in one brand at ~100 °C at an average concentration of 748 ± 36 ng/L. Subsequent mass loading calculations demonstrated that bioaccumulation of BPA from Brand C after high levels of temperature exposure well exceeded the tolerable daily intake (TDI). Findings in this study indicate that consumers should not be expected to incur harmful exposures to the target compounds under normal conditions as analytes were not measured in water bottle samples at 25 °C or 60 °C. Further studies should explore a more nuisance approach to heating over long durations, including that of ultraviolet exposure.
The development of novel aqueous cross-coupling strategies has emerged as a rapidly expanding area of research within organic synthesis. However, many of these cross-coupling reactions require the pre-formation of an organohalide substrate, which often involves toxic halogenating reagents and harsh reaction conditions. This work details the development of a tandem halogenation/cross-coupling procedure in which an electron-rich arene or heteroarene is brominated through an enzymatic halogenation reaction catalyzed by a vanadium dependent haloperoxidase (VHPO) and then used without workup in a subsequent aqueous Suzuki cross-coupling reaction. This sequential process allows the arylated product to be accessed in a single pot from the unfunctionalized substrate via the brominated intermediate. Optimization of the enzymatic halogenation step was performed for three different substrates, resulting in the discovery of conditions for the bromination of 2,3-dihydrobenzofuran, chromane, and anisole in high yield (>95%). The scope of the reaction was then investigated for a range of electron-rich arene and heteroarene substrates. Next, Suzuki cross-coupling conditions were developed in a reaction mixture of pH 5 citrate buffer and acetonitrile and applied to the arylation of 2,3-dihydrobenzofuran utilizing an array of arylboronic acid coupling partners. Finally, the two procedures were combined to perform a tandem enzymatic halogenation/aqueous Suzuki cross-coupling of 2,3-dihydrobenzofuran to give the arylated product in 74% yield.
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.
The status of Earth’s diversity is deteriorating quickly which will continue to impact humans’ way of life, as well as every other living creature, in all regions of the world. However, there are organizations taking action to protect biodiversity on our planet. The Convention on Biological Diversity (CBD) is one of those organizations and includes 196 signatories from around the world who are committed to strategies to preserve their biodiversity (Secretariat). Indeed, 98% of the parties which have participated in the Convention on Biological Diversity (CBD) have created national biodiversity strategies (NBS) and action plans (NBSAPs) (Secretariat). Yet, there are still countries that have yet to partake in these efforts. America continues to hold out against ratifying the CBD and remains the only developed country without a National Biodiversity Strategy. As an NBS for the U.S. is under consideration, my goal is to understand what works from previous plans. In particular, I focus on stakeholder engagement in Conservation Biodiversity Action Plans. Stakeholder engagement is important because, without it, there may be insufficient levels of integration of the action plans, which can lead to the failure of the CBDs conservation efforts. To address this question, I analyze the 193 strategies created for countries across the globe. My review describes the ways that stakeholders are engaged in National Biodiversity Strategies for CBD member countries. All plans mention some form of engagement. The most common types mentioned are ‘Education’, ‘Communication’, and ‘Training’. Examining the plans further reveals that most forms of engagement often are just mentioned and not completed. Close to 58% of the engagement forms are only completed about 50% of the time. Exceptions are surveys, interviews, and workshops, which are each completed in over 70% of plans that mention them. I then use this information to provide practical recommendations for creating an effective NBSAP for the United States.