Hydroformylation of olefins with formaldehyde in the presence of RhHCO(PPh3)(3)

Olefins, such as allyl alcohol, propylene, 1-hexene, styrene, methyl acryla te and acrolein, were hydroformylated with formaldehyde to form correspondi ng aldehydes. Allyl alcohol and methyl acrylate which have oxygen at beta p osition to double bond showed higher reactivities and selectivities to n-pr oducts than those of olefins without oxygen such as propylene, 1-hexene and styrene. 4-Hydroxybutanal was formed as a major product from the reaction of allyl alcohol with formaldehyde under nitrogen atmosphere at 100 degrees C and 5 h (yield: 26%, n- / iso- = 21). The addition of syn-gas or excess phosphine to the reaction mixture inhibited hydroformylation with decreasin g n- / iso-ratio. The hydroformylation of olefins without oxygen gave bette r yield to aldehydes under syn-gas condition. From in situ IR experiments, the formation of formyl ligand coordinated to metal center was observed, Va riable temperature NMR experiment was also performed to verify the mechanis m. Based on those observations, a plausible reaction mechanism was proposed . (C) 1999 Elsevier Science B.V. All rights reserved.