Nouveaux complexes de Pd et Ni pour la synthèse d’acide adipique par alkoxycarbonylation du butadiène.

Adipic acid is considered as the most important dicarboxylic acid of global market and it has been included among the 50 most used chemicals in the US. Its main application concerns the synthesis of polyamides-6,6, also called “Nylon”, which demand about 50% of the global production of adipic acid. Today, this chemical is obtained via a petrochemical process starting from cyclohexane oxidation. Furthermore, this methodology implies the generation of important amounts of N2O, a gas molecule whose greenhouse effect is estimated to be of about 300-fold higher than that of CO2! Therefore, there is a high interest in the development of new environmentally friendly synthetic pathways allowing us to prepare adipic acid starting from renewable sources, while keeping high values of productivity and avoiding the formation of pollutant side-products.
An interesting route for the preparation of adipic acid from renewable sources implies the utilization of butadiene, which can be directly obtained from bioethanol (which in turn is produced through sugars fermentation), as platform molecule. The corresponding adipate is prepared through the alkoxycarbonylation of butadiene in the presence of CO and an alcohol. This reaction can be considered as fully « sustainable », as CO can also be obtained through the “reverse water-gas shift” reaction or CO2 semi-reduction. Once the adipate is synthesized, a final hydrolysis step would allow us to obtain a fully “renewable” adipic acid.
The present PhD aims to prepare new ligands and their corresponding organometallic complexes for their use as catalysts in the alkoxycarbonylation of butadiene. In addition, mechanistic studies at both theoretical at experimental level will be performed.

Keywords: Organometallic/organic synthesis, coordination chemistry, homogeneous catalysis, NMR, theoretical calculations.