Patent attributes
A process for the hydrocarboxylation of an ethylenically unsaturated carboxylic acid, by reacting it with carbon monoxide and a co-reactant selected from the group of water and carboxylic acids in the presence of a catalyst system including: (a) a source of palladium; (b) a bidentate diphosphine of formula (I), R1R2>P—R3—R—R4—P<R5R6 (I) wherein P represents a phosphorus atom; R1, R2, R5 and R6 independently represent the same or different optionally substituted organic groups containing a tertiary carbon atom through which the group is linked to the phosphorus atom; R3 and R4 independently represent optionally substituted alkylene groups and R represents an optionally substituted aromatic group; (c) a source of anions derived from an acid having a pKa of less than 3, as measured at 18° C. in an aqueous solution.
