Unveiling Stereo-Electronic Effects in Homogeneous Catalysis Integrating Theory and Experiments: the Potential of Dimeric Iron(III) Salen Complexes in Methyl Levulinate Transesterification

Biomass represents an abundant and renewable source of raw materials that can be effectively converted into intermediates and base chemicals. Among these, levulinic acid has garnered significant attention due to its direct derivation from lignocellulosic biomass and the presence of two functional groups, a carboxylic acid, and a ketone, enabling diverse transformations into valuable products. Levulinic acid esters have already found applications in various industrial sectors such as cosmetics, plasticizers, and solvents. In this study, a broad array of alkyl levulinates has been successfully synthesized through homogeneous transesterification catalyzed by Lewis acids. A systematic screening of a library of mu-oxo-dinuclear Fe(III) salen complexes has been conducted, aiming to elucidate the impact of steric and electronic properties of their substituents. A complementary theoretical-computational study based on quantum mechanics calculations and machine learning regression techniques has been employed to unravel the relationship between the structure of the catalysts and their corresponding properties, shedding light on the key factors influencing their catalytic performance. center dot Structure-activity relationship of Fe(III) salen dimeric catalysts for methyl levulinate transesterification.center dot DFT and Machine Learning techniques correlate Fe-O-Fe angle and LUMO energy with catalytic activity.center dot Comprehending electronic and steric effects in Lewis-acid catalysis and rational catalyst design.center dot High-yield synthesis of industrially relevant esters under mild conditions.+image