Date of Award

6-2017

Degree Name

Master of Science

Department

Chemistry

First Advisor

Dr. Michael Barcelona

Second Advisor

Dr. Sherine Obare

Third Advisor

Dr. Yirong Mo

Keywords

Green solvent, water, lactone, N-heterocyclic carbine, characterization

Access Setting

Masters Thesis-Open Access

Abstract

Given the declining state of the natural environment, identifying green methodologies in synthetic chemistry is becoming paramount. An under explored area of green chemistry, is the use of catalytic systems in green solvents. One interesting concept in green chemistry is the use of N-Heterocyclic Carbenes (NHCs) as organocatalysts.

Thiamine or vitamin B1 was one of the first NHCs recognized. Thiamine is required for carbohydrate metabolism and helps the cell produce adenosine triphosphate (ATP). Over the last 20 years NHCs have been found to be efficient catalysts in carbon-carbon bond forming reactions.

But to date, little research has been done exploring the use of NHCs in unconventional solvent systems. Typical solvents of choice for reactions involving a homoenolate anion with a Michael acceptor include dichloromethane, tetrahydrofuran or alcohols. Investigations into reactions regarding homoenolate anions with a Michael acceptor in newer green solvents has received little to no attention. I will show the formation of cyclic compounds, most notably γ-butyrolactone(GBL) rings using water as a solvent.

Characterization of lactone products will be completed by advanced computational methods using Gaussian View software suite. The optimized geometries of lactones are obtained from density functional theory(DFT) calculations; at B3YLP/6-31G + (d, p) level of theory.

Since the parent lactone structure GBL shows bio-activity and has been used as a recreational street drug, further characterization will include a toxicology report.

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