Carbonylation as a route to chemicals from biomass

As oil stocks dwindle and become increasingly expensive, it will become essential to develop routes to chemicals starting from feedstocks that can be derived from plant sources. One interesting group of chemicals is the diesters. Especially desirable are the alpha-omega diesters since they are used in a wide variety of polyesters for use in plastic bottles, sythetic carpets and speciality plastics.
We have been developing a range of palladium based catalysts that can form alpha-omega diesters from unsaturated esters by methoxycarbonylation reactions.When these catalysts are applied to methyl oleate, dimethyl 1,19-nonadecanedioate is formed in high selectivity. This remarkable reaction involves isomerisation of the double bond to the end of the chain and, only when it is there, is it carbonylated. The same product is formed from methyl linoleate on methyl linolenate.
Since shorter chain length diesters are often required, the group of W. R. Jackson in Monash Australia has coupled this isomerisation carbonylation reaction with metathesis of the original oil with butene. The metathesis shortens the chain to give an unsaturated ester which can be isomerised and carbonlyated to give shorter alpha-omega diesters.
We shall discuss the nature of the catalysts and the reasons for their very specific actions.