BIDENTATE LIGANDS USEFUL IN CATALYST SYTEMS

摘要

Bidentate ligand of formula II,wherein M<1 >and M<2 >are independently P, As or Sb; R<1>, R<2>, R<3 >and R<4 >independently represent tertiary alkyl groups, or R<1 >and R<2 >together and/or R<3 >and R<4 >together represent an optionally substituted bivalent cycloaliphatic group whereby the two free valencies are linked to M<1 >or M<2>, and R represents a bivalent aliphatic bridging group containing from 2 to 6 atoms in the bridge, which is substituted with two or more substituents. A catalyst system comprising:a) a source of group VIII metal cations;b) a source of such a bidentate ligand; andc) a source of anions, and use of such a catalyst system in a process for the carbonylation of optionally substituted ethylenically or acetylenically unsaturated compounds by reaction with carbon monoxide and a coreactant is provided.