A MECHANISTIC STUDY OF RHODIUM TRI(ORTHO-TERT-BUTYLPHENYL)PHOSPHITE COMPLEXES AS HYDROFORMYLATION CATALYSTS

A mechanistic study of the hydroformylation cycle with a rhodium tri(o-t-butylphenyl)phosphite complex as catalyst is presented. Spectroscopic experiments prove that under hydroformylation conditions this complex is coordinated by only one phosphite. The complex has a high activity in the hydroformylation of otherwise unreactive alkenes. The catalyst also gives a very high rate of isomerization. Isotope studies indicate that the aldehyde-forming step proceeds via a direct reaction of the rhodium acyl complex with dihydrogen and not via a bimolecular reaction of a rhodium hydride and a rhodium acyl complex.