Adaptive hybrid ligands for Catalysis: new routes for activating stable C–H and C–O bonds – ALCATRAS

SUMMARY AND ADEQUATION TO THE CALL

The present program is a fundamental research project aimed at developing innovative catalytic tools for specifically addressing at short- and mid-term, respectively, two contemporary synthetic industrial challenges: i) the regioselectivity limitations of metal-catalysed direct C–H functionalization of heteroaromatics, and ii) the restrictions in organocatalytic (non-metal) C–O bond activation within CO2 resource. We propose, on the basis of air-stable, temperature-robust versatile ferrocenyl platform (Fc), to design new hybrid acidic (Brønsted and Lewis acids) phosphine ligands with adaptive structures. Additionally, the ferrocene ligand synthesis proposed herein, because of this adaptive aspect, allows also for the synthesis of novel methylamino/borane species that can be valued in further organocatalytic (non-metal) catalysed C–H functionalization of heteroaromatics. Thus, entire new classes of ligands would be designed from a careful structure/reactivity approach (experimental and computational), and would provide auxiliaries for palladium-catalysed C–H functionalization with new selectivity, as well as potentially marketable organocatalysts for CO2 activation and heteroaromatic C–H functionalization – beyond the current proofs of concept. Owing to the robustness and versatility of the targeted tools the potential for industrial application would be much reinforced.

This project, in addition to address several fundamental aspects (cooperative ligands in metal and organocatalysis) adequately suits the terms of the call Axe 4: “Chimie Durable, produits, procédés associés” in the “Défi 3 : Stimuler le renouveau industriel”. Several claims in the call perfectly fit the present project, i. e.: “La chimie doit aujourd’hui répondre aux enjeux du développement durable …Pour cela, elle doit accélérer l’évolution de ses pratiques pour réduire sa consommation en matières premières, son coût énergétique et son impact environnemental…la recherche de matières premières alternatives activation du CO2, de molécules C1-C3…”. The applied objective fits the terms of the call concerning “La catalyse est un principe essentiel de la chimie durable et au cœur des grands défis industriels de demain. Les innovations attendues concernent : (i) tous les types de catalyse à savoir … catalyse organométallique, organocatalyse…”. As mentioned above and further detailed below concerning “Adaptive hybrid ligands”, the bifunctional ferrocenes we propose for development (phosphino/carboxylate, phosphino/borane, amino/borane) are the results of a rational conception based on the robustness of the ferrocene platform, intramolecular CMD concept, and Lewis pairs chemistry. Thus, as mentioned in the call this was done for generating innovation “Afin de favoriser l’émergence de ces innovations, une approche basée sur la conception rationnelle (relations structure…) des catalyseurs est à privilégier.” Since the Dijon-Rennes consortium in previous projects successfully designed ligands for promoting difficult C–H functionalization: ligands which are now commercialized and available worldwide, the credibility of this consortium is recognizable. Its extension to international cooperation with a north-american research group of the highest level is also a strong point of this ANR project.