A novel thermoregulated phosphine ligand used for the Rh-catalyzed hydroformylation of mixed C_11-12 olefins in aqueous/organic biphasic system

A novel thermoregulated phosphine ligand Ph₂P(CH₂CH₂O)_nCH₃ (n = 22) was synthesized and used for the Rh-catalyzed hydroformylation of mixed C_11-12 olefins in aqueous/organic biphasic system. Under the optimized conditions, pressure = 5 MPa (H₂:CO = 1:1), phosphine/Rh = 13 (molar ratio), reaction time = 6 h and temperature = 130 °C, the conversion of C_11-12 olefins and the yield of aldehyde are 99% and 94%, respectively. The catalyst retained in aqueous phase can be easily separated from the product-containing organic phase by simple phase separation and the catalytic activity remains almost constant after four consecutive cycles.