Efficient Catalysts for the Two-Phase Hydroformylation of Long-Chain α-Olefins

In this paper, we report on novel Rh/phosphonate−phosphine catalysts for the aqueous two-phase hydroformylation of long-chain olefins. The amphiphilic ligands Ph 2 P−(CH 2 ) 10 −PO 3 Na 2 and Ph 2 P−(CH 2 ) 12 −PO 3 Na 2 have been shown to form Rh catalysts that are superior to Rh/TPPTS systems. Aldehyde selectivities higher than 95% and high activities (e.g., TOF of 660 h -1 at 88% yield) were achieved. Counterions such as Na +, K +, NH 4 +, and NH 3 Pr + influence the catalyst retention, whereas the lowest rhodium losses into the organic phase were found with a sodium phosphonate ligand. Phase separation by simple decantation was accelerated when methanol was added to the biphasic system.