PREPARATION OF ARALKANOIC ACIDS AND ESTERS USING MIXED LIGAND CATALYST

摘要

The activity of a palladium catalyst in the carboxylation of an aralkene with carbon monoxide and water or an alcohol in the absence of oxygen can be enhanced when it is used in conjunction with (A) a ligand mixture comprising compounds corresponding to the formulas R3ZY and R'3Z wherein each R and R' is independently selected from alkyl, aryl and substituted aryl groups; Y is a member of Group VIA of the Periodic Table; and Z is an element having a Pauling electronegativity of 1.9-2.5 or (B) a complex ligand providing all of the elements of said mixture. The invention has particular utility in carboxylating an aralkene such as 4-isobutylstyrene or 2-methoxy-6-vinylnaphthalene to ibuprofen or naproxen or their esters; and the preferred novel ligand is usually a 50/50 mixture of phosphine and phosphine oxide.