Solvent effects in hydroformylation of long-chain olefins

• Published in: Molecular catalysis 2021-03, Vol.503, p.111429, Article 111429
• Main Authors: Jameel, Froze, Stein, Matthias
• Format: Article
• Language: English
• Subjects: DFT; Homogeneous catalysis; Rhodium; Solvent design; Sustainable chemistry
• ISSN: 2468-8231; 2468-8231
• DOI: 10.1016/j.mcat.2021.111429

[Display omitted] •Hydroformylation of long-chain olefins from renewable sources is one step in the transformation of chemical processes towards sustainability.•Computational means can be used to rationalize the Rh(BiPhePhos) catalyst’s selectivity.•The mechanisms of the linear hydroformylation path plus isomerization and hydrogenation side reactions are elucidated in molecular detail.•The solvent effects on thermodynamic equilibria and activation energies in a mixed DMF/dodecane solvents at various compositions are discussed. With the increasing concern about climate change, a transformation of chemical processes from petrochemicals towards renewable, sustainable feedstock is indispensable. This transition, however, requires a careful assessment of the transferability of kinetic and thermodynamic data and reaction mechanisms. Here, the rhodium-catalyzed hydroformylation reaction of a long chain olefin (1-decene) from renewable resources with synthesis gas (CO/H2) is investigated. The bidentate phosphite ligand (BiPhePhos) shows a high degree of selectivity towards the desired n-aldehyde. This selectivity can be rationalized by kinetic discrimination at the branching point, i.e. the transition state of the hydride insertion step. Formation of the iso-aldehyde is kinetically and thermodynamically discriminated. The complex multi-step reactions of the desired hydroformylation reaction pathway with respect to the side-reactions such as olefin isomerization and hydrogenation are elucidated in detail. The solvent effects of a mixed polar/non-polar thermomorphic solvent system (DMF/dodecane) on chemical equilibria and activation energies were investigated using the COSMO-RS solvent model. Solvent screening for the overall rate-determining step gives a perspective as to solvent control of the process.