Cu₂O-mediated regio- and stereoselective one-pot synthesis of (Z)-3-ylidenephthalides from 2-iodobenzoic acids and terminal alkynes

A series of substituted (Z)-3-ylidenephthalides was synthesized from 2-iodobenzoic acids and various terminal alkynes in the presence of Cu2O in DMF at 100-130 °C. Our copper(I) oxide-catalyzed reaction requires no additional palladium, ligand, or base, making it an economical and efficient process. This optimized method is applicable to a range of 2-iodobenzoic acids and alkynes with diverse electronic, steric, and stability characteristics.