Description of the thesis topic

Numerous chemical reactions require a combination of catalytic sites and/or functional groups to be accelerated efficiently and selectively. In the realm of metal-catalyzed asymmetric reactions, metal complexes embedding a combination of different ligands are usually more appropriate than those containing a single type of ligand. One limitation is that the preparation of a library of catalysts containing different catalytic sites or ligands connected through covalent bonds requires a huge synthetic effort. More recently, the different units constituting the catalyst backbone have been connected through non-covalent interactions paving the way to an alleviated generation of catalyst libraries.[1] Whilst most of supramolecular catalysts reported to date are of finite size, we developed a new class of catalysts for which the catalytic centres (rhodium, copper) are located at the periphery of a supramolecular helical polymer.[2] The chirality is efficiently transferred from a catalytically inactive enantiopure monomer to the achiral metal center, the selectivity of the reaction being dictated by the optical purity of the helices and their handedness. We recently envisaged the possibility to extend our concept to helices composed of different catalytic sites and/or functional groups with the aim of improving the efficiency of catalytic reactions, notably through a cooperative activation of two substrates or through directed non-covalent interactions with a single substrate.[3] A crucial point is to control the sequence of the monomers in order to favour the interaction between the different catalytic sites. We plan to use a set of complementary monomers functionalized with different chemical groups.

Work Context

The PhD student will be supervised by Matthieu Raynal and will candidate through the competitive framework established by ED397 of Sorbonne Université. Our team has a strong expertise in the preparation and characterization of hydrogen-bonded supramolecular polymers.