| abstract |
A process for the carbonylation of a conjugated diene, comprising reacting the conjugated diene with carbon monoxide and a co-reactant having a mobile hydrogen atom in the presence of a catalyst system including: (a) a source of palladium; and (b) a bidentate diphosphine ligand of formula (II): R1R2 > p1R3m-R-R4n-p2 < R5R6 wherein p1 and p2 represent phosphorus atoms; R1, R2, R5, and R6 independently represent the same or different optionally substituted organic radical containing a tertiary carbon atom through which each radical is linked to the phosphorus atom; R3 and R4 independently represent the same or different optionally substituted methylene groups; R represents an organic group comprising the bivalent bridging group C1-C2 through which R is connected to R3 and R4; m and n independently represent a natural number in the range of from 0 to 4, wherein the rotation about the bond between the carbon atoms C1 and C2 of the bridging group is restricted a temperature in the range of from 0 ~C to 250 ~C, and wherein the dihedral angle between the plane occupied by the three atom sequence composed of C1, C2 and the atom directly bonded to C1 in the direction of p1, and the plane occupied by the three atom sequence C1, C2 and the atom directly bonded to C2 in the direction of p2, is in the range of from 0 to 120~; and (c) a source of an anion. |