Date of Award
Chemistry and Biochemistry
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The first chapter of the thesis covers a simple one-step methodology to synthesize N-acyl-α-amino amides directly from α-keto esters and ammonia. The factors that govern this reaction have been studied, and the mechanism through which it proceeds has been briefly investigated. The substrate scope of the methodology was found to be broad, and a wide range of N-acyl α-amino amides were synthesized in good to excellent isolated yields. In all cases the desired products were isolated in high purity by crystallization, and did not require further chromatographic purification. The X-ray crystal structures of three N-acyl α-amino amides were also obtained. In addition, the acid hydrolysis of these derivatives was shown to furnish the corresponding unnatural α-amino acids in high yields after purification by ion exchange chromatography. The second chapter of the thesis describes our progress towards the synthesis of chiral acyclic diaminocarbenes (ADC), and their ultimate application as ligands in enantioselective catalysis. Towards this end, we have synthesized six chiral formamidinium salts, as precursors to chiral ADC with either C 2- or C1-symmetry, in good to excellent yields. An X-ray crystal structure of a C2-symmetric formamidinium iodide salt was obtained. In addition, the attempted formation of a chiral ADC-metal complex from the corresponding formamidinium salt, via deprotonation with LDA and reaction with the metal salt, instead resulted in the isolation of the corresponding urea. The structure of the urea was proven by X-ray crystallography, and its formation was assumed to arise from the oxidation of the free chiral ADC with adventitious oxygen.
Ntaganda, Rukundo, "Synthesis of N-acyl α-amino amides and the study of chiral acyclic diaminocarbenes" (2009). Electronic Theses and Dissertations. 8205.