Solvent dependence of the palladium catalyzed telomerization of isoprene with methanol

The palladium catalyzed telomerization of isoprene with methanol as a nucleophilic agent has been investigated, applying the reaction system Pd-complex, tributylphosphine, sodium methylate, isoprene and methanol in a ratio of 1232002000. Two main products were found: 1-methoxy-3,6-dimethylocta-2,7-diene with a head-head coupling (I) and 1-methoxy-2,6-dimethylocta-2,7-diene with a tail-head-coupling (II). By substituting part of the methanol by different solvents the formation of I and II, respectively, can be controlled to a large extent.