Metals in organic syntheses II. The effect of molecular hydrogen on the highly regioselective hydrocarboxylation of propene promoted by a [PdCl2(PPh3)2]-PPh3 catalyst precursor

The hydrocarboxylation of propene with MeOH or n-BuOH promoted by [PdCl2(PPh3)2] as catalyst precursor in combination with added PPh3, occurs with high selectivity towards the linear ester, particularly at low Pco. The yield is almost independent of Pco (in the range, 13-95 atm) when using MeOH and decreases on decreasing Pco with n-BuOH. With this alcohol the yield can be increased in the presence of molecular hydrogen, while maintaining high the selectivity and without aldehyde formation; this hydrogen effect is observed also with MeOH when using toluene as solvent.