Ligand hydrogenation during hydroformylation catalysis detected by in-situ high-pressure infra-red spectroscopic analysis of a rhodium/phospholene-phosphite catalyst
Abstract
Phospholane-phosphites are known to give highly unusual selectivity’s towards branched aldehydes in the hydroformylation of terminal alkenes. This paper describes the synthesis of hitherto unknown unsaturated phospholene-borane precursors and their conversion to the corresponding phospholene-phosphites. The relative stereochemistry of one of these ligands, and it’s Pd complex was assigned with the aid of X-ray crystal structure determinations. These ligands were able to approach the level of selectivity observed for phospholane-phosphites in the rhodium catalysed hydroformylation of propene. High-Pressure-Infra-Red (HPIR) spectroscopic monitoring of the catalyst formation revealed that whilst the catalysts show good thermal stability with respect to fragmentation, the C=C bond in the phospholene is slowly hydrogenated in the presence of rhodium and syngas. The ability of this spectroscopic tool to detect even subtle changes in structure, remote from the carbonyl ligands underlines the usefulness of HPIR spectroscopy in hydroformylation catalyst development.
Citation
Fuentes , J A , Janka , M , McKay , A , Cordes , D B , Slawin , A M Z , Lebl , T & Clarke , M 2024 , ' Ligand hydrogenation during hydroformylation catalysis detected by in-situ high-pressure infra-red spectroscopic analysis of a rhodium/phospholene-phosphite catalyst ' , Molecules , vol. 29 , no. 4 , 845 . https://doi.org/10.3390/molecules29040845
Publication
Molecules
Status
Peer reviewed
ISSN
1420-3049Type
Journal article
Collections
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.