Wittig-Horner Reaction of Dimethyl Phthalide-3-phosphonates with Ketones: Synthesis of 3-Ylidenephthalides and Their Conversion to 2,2-Disubstituted Indan-1,3-diones Including Spirocyclic Compounds
A simple and efficient palladium-catalyzed intramolecular carbonylativesynthesis of isocoumarins and phthalides from the easily available starting materials by employing phenylformate as a CO surrogate has been achieved. The approach affords target compounds in good to excellent yields with the advantages of lower toxicity, milder conditions, easy operation and wide functional group tolerance.