Aqueous asymmetric aldol reactions in polymersome membranes

l -Proline catalysts have been immobilised in the hydrophobic domain of a polymersome via a copper( i )-catalysed azide–alkyne cycloaddition (CuAAC) reaction. Utilisation of these nanoreactors in the asymmetric aldol reaction of cyclohexanone with 4-nitrobenzaldehyde afforded the corresponding β-hydroxyketones in quantitative yields and with excellent enantio- and diastereoselectivities. The polymersomes were recycled up to five times without any loss in activity or selectivity.