Developing Boron-based Receptors for Cell-surface Carbohydrates using Induced Intramolecularity

Abstract

Boron acids are very useful in many organic syntheses, particularly as catalysts or participating agents. Their catalytic properties are featured in common functional group transformations including amidations, esterifications and cycloadditions. However, boron acids are more commonly known for having a binding affinity for vicinal diols and polyols. The reversible, covalent interaction between boron and diols is a natural phenomenon important to several biological processes. Chemists have worked over several centuries to understand these complexes. This covalent interaction that occurs between the boron acid and cis-diols has been exploited in an attempt to target specific polyols, with the design and synthesis of carbohydrate sensors as well as inhibitors of enzymes and artificial lectins. The first part of this thesis provides a literature overview of the potential application of boron-based receptors as both diagnostic tools and drug delivery-agents in diseases. Our aim was to utilise boron acids affinity towards diols as an accelerant to facilitate the formation of novel receptors for cell-surface carbohydrates. Within some disease states, particular aberrant carbohydrates become potential sensor targets for disease detection. Specifically, the Mycobacteria cell wall contains bacteria unique structural fucose and galactose residues that could be detectable via a boron-based carbohydrate sensor.