Development of new palladium catalysts for the alkoxycarbonylation of aryl chlorides

The alkoxycarbonylation of different aryl chlorides was studied. Studies of the butoxycarbonylation of 4-chlorobenzotrifluoride and chlorobenzene using chelating ferrocenylphosphines reveal the advantages of these ligands compared to the well-known tricyclohexylphosphine (PCy3). (1-{2-(Dicyclohexylphosphino)ferrocenyl}ethyldicyclohexylphosphine (4) was shown to give the most active palladium catalyst system. The usefulness of this catalyst is demonstrated in the alkoxycarbonylation of various aryl chlorides. Optimized carbonylation conditions were realized by a statistical design of three critical reaction parameters.