Precious Metal Catalysts for Homogeneous Catalysis
Hydroformylation, also known as oxo synthesis, was discovered in 1938 by Otto Roelen. It involves the homogeneously catalyzed transformation of unsaturated compounds, generally olefines, with carbon monoxide and hydrogen to form aldehydes.
In the industrial application of the hydroformylation reaction, the production of n-butyraldehyde from propene and synthesis gas is of outstanding significance. Butyraldehyde is the precursor product for the synthesis of dioctylo-phthalate which is employed as a plasticizer in plastics. Initially, cobalt complexes were used as catalysts. Later, more active rhodium catalysts were developed so that the reaction could be carried out at substantially lower temperatures and pressures. Important rhodium catalysts and catalyst precursors for hydroformylation are rhodium acetate, (acetylacetonato)dicarbonylrhodium(I), and (acetylacetonato)carbonyl(triphenylphosphane)rhodium(I).