First rhodium-catalyzed hydroformylation of cyclopentadiene

•A Rh-catalyzed hydroformylation of cyclopentadiene to C6-aldehydes was described.•Possibility to steer the reaction via the bite angle of diphosphine ligands.•Dimerization of cyclopentadiene was overcome by using NEt3 as additive.•Cyclopentene and the unsaturated C6-aldehyde have been observed as intermediates.

This paper describes the first rhodium-catalyzed hydroformylation of cyclopentadiene (Cpd) using a homogeneous catalyst system consisting of [Rh(OAc)2]2 and the chelate ligand BISBI. At a reaction temperature of 100 °C and a syngas pressure of 30 bar the cyclopentane carbaldehyde is formed in 68% yield while 20% of the respective dialdehyde species are obtained within 3 hours. An important side reaction in Cpd hydroformylation reaction can be the dimerization of Cpd to its dimer dicyclopentadiene (Dcpd). This unwanted side reaction could be overcome by the use of tertiary alkyl amines as additives. Furthermore, the possibility to steer the reaction via the influence of the bite angle of diphosphine ligands was found.

Graphical abstractThe transition metal catalyzed hydroformylation is a very important reaction in industrial chemistry. Here we present the first rhodium-catalyzed hydroformylation of the unsaturated basic chemical cyclopentadiene leading to the corresponding saturated C6-aldehyde and C7-dialdehyde.Figure optionsDownload full-size imageDownload high-quality image (123 K)Download as PowerPoint slide