Non Natural Aromatic Amino Acids Applications in cage-construction, metal ion coordination and asymmetric catalysis

Sammanfattning: Aromatic non-natural amino acids, the outstanding feature of which was the presence of several arms, were synthesised and their properties investigated. The amino acids were synthesised following a standard procedure starting with a Horner-Wadsworth-Emmons or a Heck reaction, which provided didehydroamino acids. Catalytic asymmetric hydrogenation produced the enantiopure amino acid precursors. The different protecting groups appended to the carboxylic and amino terminals, respectively, were removed selectively to provide the partially or completely deprotected amino acids. Studies towards the construction of a bowl-shaped C3-symmetric molecular receptor were embarked on. These studies culminated with the synthesis of a pair-wise deprotectable scaffold. Information gathered from these studies was then implemented in the synthesis of C3-symmetric cage-like trisamides. Investigations of the metal ion coordinating properties of the non-natural amino acids to lanthanide ions, Eu(III) and Tb(III), were performed and monitored by different spectroscopic methods: NMR, UV and fluorescence. Tris, bis and mono-phenylalaninol derivatives were explored as chiral ligands in asymmetric catalysis, in the addition reaction of diethylzinc to benzaldehyde.