The unique behavior of the catalytic system Pd(OAc)2/N-heterocyclic carbene on the telomerization of isoprene with methanol

The catalytic system Pd(OAc)2/1,3-bis(2,4,6-trimethylphenyl)imidazolium chloride (IMes · HCl) promotes the telomerization of isoprene with methanol resulting in methoxy-dimers with a head-to-head coupling of the isoprene units at unprecedented activity and selectivity. Employing 1,3-bis(2,6-di-i-propylphenyl)-4,5-dihydroimidazolium tetrafluoroborate (SIPr · HBF4) instead of IMes · HCl, new sesquiterpenes are obtained by the trimerization of isoprene.