Novel amphiphilic poly(2-oxazoline)s bearing l-prolinamide moieties as the pendants: Synthesis, micellization and catalytic activity in aqueous aldol reaction

A novel class of amphiphilic poly(2-oxazoline) derivatives bearing l-prolinamide moieties at the alkyl side-chain termini has been synthesized. Upon direct dissolution in water, the polymers self-assembled into micelle-type aggregates with a particle size of 10-30 nm, as evidenced by 1H NMR and DLS measurements together with TEM images. The assembled nanoparticles were successfully employed as a nanoreactor to perform the asymmetric aldol reaction of p-nitrobenzaldehyde with cyclohexanone in aqueous media. It was found that the polymeric micelles exhibited much higher catalytic activity compared to their monomeric counterpart and non-amphiphilic reference polymer, affording the anti-aldol products with a moderate stereoselectivity in good yield.165