We have prepared a range of well-defined copolymers of styrene and l-proline functionalized styrene (5–11 kDa) using reversible addition–fragmentation chain transfer (RAFT) polymerization techniques and explored their use in supported catalysis. Upon deprotection of the l-proline functionalities, the solution self-assembly of these copolymers was investigated in mixed solvent systems. The resulting assemblies were characterized by dynamic light scattering, transmission electron microscopy (on graphene oxide substrates, along with cryo-TEM and tomography), and scanning electron microscopy. The application of these functional assemblies as supported catalysts for the aldol condensation reaction was explored using cyclohexanone and 4-nitrobenzaldehyde. The rate and selectivity of solution catalysis in our self-assembled system were comparable to those of l-proline, and a significant advantage of our system was that the polymer support could be utilized at lower catalyst loadings with comparable activity and also could be recycled a number of times while maintaining activity and selectivity.

Two families of organocatalytically active polystyrene-based copolymers with tunable incorporations of 4-hydroxyproline have been synthesized using two different controlled radical polymerization technologies: nitroxide-mediated polymerization (NMP) and reversible addition−fragmentation chain transfer (RAFT) polymerization. Both of these methodologies allow ready access to a number of polymeric species with controllable molecular weights, narrow molecular weight distributions (ca. 1.2), and reliable functionality incorporations (between 3 and 26%). The organocatalytic activity and selectivity of the NMP-derived family of copolymers with variable incorporations of l-proline have been investigated using the aldol reaction, which provided high conversion to products (>95%) with very good diastereo- and enantioselectivities. We propose that these materials have potential as highly efficient recoverable organocatalyst supports whose solubility and loading can be readily tailored to the desired application.