BIDENTATE LIGANDS USEFUL IN CATALYST SYSTEM

摘要

Bidentate ligand of formula (II) R<1>R<2>M<1>-R-M<2>R<3>R<4>, 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, and c) a source of anions. 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.