Novel dinuclear μ-carboxylatoruthenium complexes for the low pressure hydroformylation of terminal alkenes

Article abstract of DOI:10.1016/0304-5102(91)85030-6

A series of di-μ-carboxylatoruthenium complexes of general formula [Ru₂(μ-OOCR)₂(CO)₄L₂] were tested as precursors for the hydroformylation reaction of alkenes. It was shown that this reaction requires the CO/H₂ couple in the presence of small amounts of water in addition to the solvent. The more active system is represented by [Ru₂(μ-OAc)₂(CO)₄(PPh₃)₂] and a slight excess of triphenylphosphine (P/Ru=5) at 3 MPa. Although a modest reaction rate was noted (2.5 h^-1), aldehydes were selectively obtained, the linear aldehydes being recovered with 80% selectivity in the best conditions. In some cases, especially when the P/Ru ratio=1 or with the less basic ligands, some isomerization of the alkene was observed but hydrogenation of the substrate or of the aldehydes was never detected.