Telomerisation of long-chain dienes with alcohols using Pd(IMes)(dvds) catalyst

Several homogeneous palladium catalysts based on PPh3 and nucleophilic carbene (NHC) ligands were screened in the telomerisation reaction of 1,3-pentadiene with methanol. A Pd(acac)(2)-3PPh(3) system showed the highest activity; initially, poor activity was observed using the Pd(0)-NHC catalysts. However, when methanol solvent/nucleophile was replaced by longer chain alcohols 1-propanol and 1-butanol, improved activity and selectivity was observed. Similarly, 1,3-hexadiene was telomerised with 1-propanol and 1-butanol with good selectivity using Pd(IMes)(dvds) as the catalyst. Pd(II)-PPh3 systems were ineffective as catalysts for the telomerisation of 1,3-hexadiene.