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Thesis Format

Integrated Article

Degree

Master of Science

Program

Chemistry

Supervisor

Blacquiere, Johanna M.

Abstract

N-Acyl ketenimines were attempted to be synthesized catalytically by [Ru(Cp)(PPh2NPh2)(NCMe)]PF6 with phenylacetylene and 3-phenethynyl-1,2,4-dioxazol-5-one. Trapping agents were employed to identify the major product of the reaction, as many products were formed. [Ru(Cp)(PPh2NPh2)(NCMe)]PF6 reacts with 3-phenethynyl-1,2,4-dioxazol-5-one generating an isocyanate via the Curtius rearrangement, confirmed by a forced Curtius rearrangement with 3-phenethynyl-1,2,4-dioxazol-5-one and 1,2,4-triazole. Rates of vinylidene formation using [Ru(Cp)(PPh2NPh2)(NCMe)]PF6 and various terminal alkynes of different sterics and electronics were evaluated using a Hammett analysis for and simple rate comparisons. Negligible trends were observed at 70 ºC. The rate of vinylidene formation with [Ru(Cp)(PCy2NPh2)(NCMe)]PF6 and phenylacetylene was faster than that of [Ru(Cp)(PPh2NPh2)(NCMe)]PF6 due to the difference in steric and electronic properties of the metal. Hydrofunctionalization reactions of 2-EBA using an [Ru(Cp)(PCy2NPh2)(NCMe)]PF6 were spiked with different alkali salts which had a positive effect on 2-EBA consumption. Different weakly coordinating anions were coordinated in-situ to Ru(Cp)(PCy2NPh2)Cl for the hydrofunctionalization of 2-EBA. It was found that the PF6-anion gave the highest consumption of 2-EBA.

Summary for Lay Audience

In this study, complexes involving ruthenium and iron were unable to produce our target product. Rather, one of the ruthenium complexes was found to follow a known reaction to produce a highly reactive molecule. Five different substrates and two different ruthenium complexes were used to investigate factors influencing the time to generate a known compound. Alterations to the substrate had no impact on the formation. However, one ruthenium complex exhibited faster formation of the desired product than the other. Furthermore, we investigated factors affecting the known transformation of 2-ethynylbenzyl alcohol (2-EBA) to isochromene.

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