Synthesis of isocoumarins via Pd/C-mediated reactions of o-iodobenzoic acid with terminal alkynes.

The coupling reaction of o-iodobenzoic acid with terminal alkynes by using a catalyst system of 10% Pd/C-Et3N-CuI-PPh3 has been studied in a variety of solvents. 3-Substituted isocoumarins were formed in good yields and with good regioselectivity when the reaction was performed in EtOH.