Metals in organic syntheses VI. The solvent effect on the hydrocarboalkoxylation of propene promoted by a [PdCl2(PPh3)2]-PPh3 catalyst precursor

The hydrocarboalkoxylation of propene promoted by a [PdCl2(PPh3)2]-PPh3 catalyst precursor occurs (at 100- 110 °C, PCO 10-100 atm) with high selectivity towards the branched isomer when a solvent is added to the alkanol. The selectivity increases on increasing the solvent/alkanol ratio, or on increasing PCO, or in the presence of LiCl, and decreases upon increasing the concentration of PPh3. The results are discussed in terms of steric effects. The yield decreases on increasing the solvent/alkanol ratio, or on increasing the concentration of PPh3, or upon decreasing Pco. Primary or secondary alkanols show comparable reactivity; tertiary alkanols give poor yields. The yield can be improved in the presence of molecular hydrogen without affecting the regioselectivity.