Telomerization of isoprene and methanol assisted by palladium-chiral phosphine and or -chiral amine complexes

In the presence of sodium methoxide and catalytic amounts of palladium(II) compounds in conjunction with a series of mono and bidentate chiral phosphines and amines isoprene produces mainly the telomer 1-methoxy-2,6-dimethyl-2,7-octadiene 2 and the isoprene dimer 2,7-dimethyl-1,3,7-octatriene 4. The formation of the dimer and telomer can be modulated by the appropriate choice of the chiral ligand. Thus, the telomer 2 is obtained almost exclusively in the presence of bidentate phosphine-amine, but with very modest e.e.'s (up to 12%). On the other hand, the isoprene dimer 4 is preferentially formed when only a nitrogen-containing ligand is employed.