A library of novel chiral DMAP derivatives were synthesised from 4-chloropyridine and 3,5-dibromo-4-chloropyridine to give a diverse range of DMAP derivatives focusing on modifications at the 3-position and 3,5-positions of pyridine in DMAP. Characteristics were included in the catalyst design to allow for the formation of intramolecular cation-π interactions, which were studied with fluorescence spectroscopy. In order to achieve the desired catalyst structure, methodology was developed to allow for the facile syntheses of a diverse range of hydrocinnamaldehydes, which were subsequently used in optimised synthetic routes towards the DMAP derivatives.
The synthesised catalysts were studied in the kinetic resolution of secondary alcohols, leading to enantioenrichment of the ester and the remaining alcohol. Attempts were made to probe the pyridinium intermediate using fluorescence spectroscopy, with characteristic cation-π fluorescence responses observed when the catalysts were both alkylated and acylated