Pd-catalyzed carbonylation of α-arylvinyl bromides: Synthesis of 2-arylacrylic esters

(1,2-Dibromomoethyl)arenes, obtained from the bromination of styrene derivatives were regioselectivley dehydrobrominated to α-arylvinyl bromides in very good yields (82–94%). The vinyl bromides generated in situ underwent palladium-catalyzed carbonylation furnishing 2-arylacrylic esters, which are precursors for non-steroidal anti-inflammatory drugs. The best catalytic system is composed of PdCl2(PPh3)2 (0.5–2 mol%), PPh3 as phosphine ligand and iPrEtN as base. The carbonylation reaction can be carried out under mild conditions (10 atm of CO, 100 °C, 3.5 h) affording the esters in very good yields (88–95%). Moreover, we have developed a one-pot deydrobromination/carbonylation procedure.

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