1,5-Hexadiene selective hydroformylation reaction catalyzed with Rh(acac){P(OPh)3}2/P(OPh)3 and Rh(acac)(CO)(PPh3) / PPh3 complexes
作者:A.M. Trzeciak、J.J. Ziółkowski
DOI:10.1016/0022-328x(94)87017-9
日期:1994.1
Hydroformylation of 1,5-hexadiene, catalyzed by the system Rh(acac)P(OPh)(3)}(2)/P(OPh)(3) (I), leads to the formation of mono- and dialdehydes, 4-heptenal, 2-Me-3-hexenal and octane-1,8-dial, 2,5-Me(2)-hexanedial respectively. The yield of dialdehydes increases with temperature and pressure and reaches 100% at 80 degrees C and 10 atm of CO/H-2=1. The reaction catalyzed by Rh(acac)(Co)(PPh(3))/PPh(3) (II) system produces, besides dialdehydes, monoaldehydes with a terminal double bond, namely 6-heptenal and 2-Me-5-hexenal. The migration of the double bonds in monoaldehydes depends mainly on the donor properties of modifying ligands. Phosphine when used as a modifying ligand (II), because of its strong donor properties, restricts isomerization (double bond migration) and diminishes yield of 4-heptenal. In contrast, when less strongly donating ligands such as phosphites are used as modifying ligands (I), independently of its steric properties, 4-heptenal is the main reaction product.