Hydrolytic Stable Ammonium Salts of Sulfonated Organic Phosphites and their Use as Cocatalysts in the Rhodium-catalyzed Hydroformylation of Olefins

Article abstract of DOI:10.1002/prac.19933350112

Ammonium salts of sulfonated organic phosphites, which are resistant to hydrolysis, have been prepared by transesterification of triphenylphosphite with mono-ammonium salt of p-hydroxyphenylsulfonic acid in yields between 66 and 76percent.A mixture containing triisooctylammonium salts of sulfonated triphenylphosphite was submitted to a test for stability to hydrolysis.The time required for hydrolysis of 7.4percent of the TPPp-SO3HN(i-octyl)3 was 3 hours under drastic conditions.Triphenylphosphite was in the same test hydrolyzed quantitatively within three hours.Tetradec-1-ene was hydroformylated by means of the catalytic systems consisting of rhodium-2-ethylhexanoate with either TPPp-SO3HN(i-octyl)3, triphenylphosphite (TPPp) or triphenylphosphine (TPP) at 125 deg C, 0.6 MPa and a rhodium concentration of 50 ppm.Higher reaction selectivities for linear aldehydes were achieved with the rhodium/TPPp-SO3HN(i-octyl)3 catalytic system.Reaction rates increased with the Rh/TPPp-SO3HN(i-octyl)3 catalyst at lower temperature (110 deg C).Using this catalyst at 110 deg C, higher yields are achieved than with the Rh/TPP or Rh/TPPp catalysts.Hex-1-ene was hydroformylated by using the catalytic systems Rh4(CO)12 with TPPp-SO3HN(i-octyl)3, Rh4(CO)12 with TPP or Rh4(CO)12 with TPPp at 125 deg C, 2.5 MPa and a rhodium concentration of 20 ppm.This confirms the above experiments which indicated that higher linear: branched aldehyde ratios were obtained with the rhodium/TPPp-SO3HN(i-octyl)3 catalyst.