CHIRPOL

This project aims at developing a novel and straightforward access to optically active polymers, following an organocatalyzed step-growth asymmetric polymerization of bifunctional prochiral monomers. We envisage developing three distinct step-growth polymerization reactions, including i) asymmetric polyaldolisation between diketones and dialdehydes, ii) asymmetric benzoin polycondensation from dialdehydes and iii) polyesterification between bis-anhydrides and diols relying on a desymmetrization of the anhydride functional group. These asymmetric processes have been considered as they have proven their high efficiency on model reactions in terms of yield, selectivity and reproducibility. Among the (non-metallic) organic catalysts that we plan to use to mediate the above processes, amine-based ones such as L-proline derivatives, quinine and N-heterocyclic carbenes (NHCs) will be particularly investigated, owing to their availability or their easy preparation in optically pure form, as well as their well-established efficacy in the transfer of chiral information. The intrinsic chirality of these appropriate organic and optically active catalysts will be transferred to the main chain, during repetitive elementary asymmetric reactions. The stereoselectivity of the three processes will be investigated by different means, including the implementation of precise model reactions such as the preparation of very short oligomers by stepwise protocols relying on protection/deprotection sequences. Based on these results, extension of the enantioselective organocatalysis to step-growth polymerization reaction between bifunctional monomers will be performed, affording new chiral polymers that should exhibit original properties.