Rhodium-catalyzed Two-phase Hydroformylation of Hex-1-ene with Sulfonated Tris(4-fluorophenyl)phosphine as Water-soluble Complex Ligands

Article abstract of DOI:10.1002/prac.19943360706

Tris(4-fluorophenyl)phosphine (TFPP) was prepared from 1-bromo-4-fluoro-benzene in 35percent yield.This phosphine was quantitatively sulfonated by using a H2SO4-SO3 mixture containing 25.5percent SO3 and 14-fold excess of SO3 to phosphine.The desired product was the trisodium salt of the trisulfonated tris(4-fluorophenyl)phosphine (TFPPTS).After 410 hours of sulfonation, hydrolysis and pH-selective separation, the resulting mixture contained 6percent TFPPTS and 94percent disodium salt of the disulfonated tris(4-fluorophenyl)phosphine (TFPPDS).Hex-1-ene was hydroformylated in a two-phase system by using the water-soluble catalytic systems Rh4(CO)12 with a mixture of 94percent TFPPDS + 6percent TFPPTS and Rh4(CO)12 with the trisodium salt of trisulfonated triphenylphosphine (TPPTS).The TFPP or TFPPTS ligand possesses a stronger ?-acidity than the TPP or TPPTS and at low P/Ph-ratios higher selectivities to linear aldehydes are achieved with the Rh/TFPP or Rh/TFPPDS + TFPPTS than with the Rh/TPP or Rh/TPPTS catalytic system.The Rh/TFPPDS + TFPPTS complex is quantitatively recovered by simple separation of the aqueous layer from the organic layer which contains the substrate and the products.