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
Catalyzed by palladium species, cyclic diaryliodonium salts underwent dual C‐aryl functionalization smoothly with activated methylene sources. With this new finding, a series of diversified fluorenes with an all‐carbon quaternarycenter was quickly constructed. Moreover, our approach also provided various novel spirofluorenes containing barburate acid or indane motifs which are featured in medicinal