Novel carbonylation ligands and their use in the carbonylation of ethylenically unsaturated compounds

摘要

Novel bidentate ligands of general formula (I) are described Formula (I): R represents a hydrocarbyl aromatic structure. The substituent(s) Yx on the aromatic structure has a total X=1-n tYX of atoms other than hydrogen such that X-1-ntYX is 4 where n is the total number of substituent(s) YX and tYX represents the total number of atoms other than hydrogen on a particular substituent YX. The groups X1, X2, X3 and X4 are joined to Q1 or Q2 via tertiary carbon atoms to the respective atom Q1 or Q2; and Q1 and Q2 each independently represent phosphorus, arsenic or antimony. A catalyst system and a process for the carbonylation of ethylenically unsaturated compounds utilising the catalyst system is also described.