CO–ethene copolymerisation catalysed by [PdCl2(PPh3)2]/PPh3/HCl in MeOH

The system [PdCl2(PPh3)2]/PPh3/HCl catalyses the carbonylation of ethene in MeOH as a solvent to give methyl propanoate (MP) or a polyketone (PK).The influence of temperature, Pd/P, CO/ethene and Pd/HCl ratios, and concentration of H2O on the catalytic activity has been studied.The catalytic system is active only in the presence of HCl and is stable when P/Pd is ≥6/1 up to 110 °C.At 100 °C, with Pd/P/HCl = 1/6/1600 (HCl initially added), under 6.0 MPa total pressure, the main product is MP at 1.0 MPa of ethene, whereas is PK when the pressure of the olefin is higher than 4.0 MPa.Water, which forms in the solvent, because of the reaction of MeOH with HCl, has a minor effect.The PK product presents a 2.5–4/1 ratio between the keto and ester end groups. The proposed catalytic cycle takes into account the results.

Graphical abstract[PdCl2(PPh3)2]/PPh3/HCl catalyses the carbonylation of ethene in MeOH to give methyl propanoate and/or a polyketone. The catalytic system is active only in the presence of HCl and is stable up to 110 °C when P/Pd is >6/1. At 100 °C, with Pd/P/HCl = 1/6/1600, under 6.0 MPa total pressure, the main product is MP at 1.0 MPa of ethene, whereas is PK when the pressure of the olefin is higher than 4.0 MPa.Figure optionsDownload full-size imageDownload as PowerPoint slide