A LOW-PRESSURE SYSTEM FOR PRODUCING NORMAL ALDEHYDES BY HYDROFORMYLATION OF ALPHA OLEFINS

A new process is described for producing predominately normal aldehydes from a olefins with high efficiencies. The process consists of a rhodium-catalyzed, low-pressure hydroformylation in the presence of significant quantities of certain phosphorus ligands. The effect of various reaction parameters on the ratio of n-vs. isoaldehyde is reported. The results are consistent with a proposed mechanism which involves as the active catalyst a pentacoordinate rhodium complex, such as tris (triphenyl phosphite)rhodium carbonyl hydride, [(C6H6O)3P]3Rh(CO)H. Both trialkyl and triaryl phosphites are effective ligands. Of particular significance are the effects obtained by substituting electron-withdrawing and electron-donating groups in the ortho and para positions of the triaryl phosphites. © 1969, American Chemical Society. All rights reserved.