Polymer-supported anionic tri-osmium and tri-iron cluster catalysts for alkene hydroformylation

The hydridic tri-iron and tri-osmium cluster anions [HM3(CO)11]− (M = Fe, Os) have been employed as soluble and supported catalysts for the hydroformylation of 1-hexene. Hydroformylation and isomerization of the alkene occurred simultaneously with both clusters. In the case of iron the integrity of the cluster was not retained, and for this reason it seems likely that several complexes are involved in the catalytic reaction. In the case of osmium, decomposition was observed for the unsupported system whereas the supported cluster anion could be recovered almost quantitatively under anhydrous conditions. High normal to branched heptanal ratios were obtained with this system.