Design, synthesis and applications of tyrosine-derived chiral functionalised polymers

This thesis documents the design and synthesis of chiral amino alcohol monomers 161, 162, 167, chiral oxazolidine monomer 168 and chiral oxazolidinone monomers 203 and 204. The synthetic strategy relies on the key Suzuki coupling of aryl triflates derived from tyrosine with p-vinylphenylboronic acid where the resultant vinyl monomers are further modified to provide the desired functionality. (Fig. 15997a) Model gel and macroporous-type suspension copolymerisations of styrene, divinylbenzene and vinylbenzylchloride are investigated to allow modification of the experimental conditions to produce chloromethylpolystyrene beads 3 in optimum yield, size, shape and uniformity. (Fig. 15997b) The chiral amino alcohol 167 and oxazolidinone 204 monomers are subsequently polymerised utilising the previously optimised suspension protocol. Characterisation of the resultant gel-type polymers 217 and 218 confirms that the functionalised monomers are successfully incorporated with the desired loading. This versatile approach to the synthesis of chiral moiety is polymer-bound thus affording complete control. Finally, the utility of the polymer-bound amino alcohol 217 as a catalyst in the addition of dialkylzinc reagents to aldehydes and the application of the supported auxiliary 218 in asymmetric alkylation and aldol reactions are evaluated.