Synthesis of 2-Arylpropionic Acids by Pd-Catalyzed Carbonylation of Vinyl Arenes with Formic Acid under Mild Reaction Conditions

Efficient synthesis of 2-arylpropionic acids by Pd-catalyzed carbonylation of vinyl arenes with CO and HCOOH is reported. Excellent regioselectivity to target 2-arylpropionic acids is achieved by the addition of some polyvinylpyrrolidone. Mild reaction conditions, available catalytic system and low Pd loading are the advantages of the proposed protocol. It was used in the total synthesis of rac-naproxen starting from commercially available 6-hydroxy-2-naphthoic acid. Additionally, vinyl acetate hydroxycarbonylation in 2-acetoxypropionic is demonstrated.