Asymmetric Organocatalysts Supported on Vinyl Addition Polynorbornenes for Work in Aqueous Media

Abstract

In an effort to identify novel polymer architectures suitable for the covalent supporting of catalysts, L–proline derivatives have been immobilized onto rationally designed vinyl addition polynorbornene (VA-PNB) resins through copper-catalyzed azide-alkyne cycloaddition (CuAAC) reactions. The fully saturated VA-PNB resins have been found to be optimal catalyst supports, the resulting proline-functionalized resins behaving as very active, easily recoverable and highly reusable organocatalysts for the asymmetric direct aldol reaction of benzaldehydes with ketones in aqueous media. The obtained results show that the combination of modular, VA-PNB resins with proline derivatives through triazole linkers represent a promising strategy for the immobilization of organocatalytic species.