Nucleophilic trapping of π-allylpalladium intermediates generated by carbopalladation of bicyclopropylidene:: A novel three-component reaction

The primary carbopalladation intermediate resulting under Heck conditions from bicyclopropylidene and phenyl iodide in the presence of tris(α-furyl)phosphane rearranges to give a π-allylpalladium complex which is efficiently trapped by various nucleophiles RnXH. This rearrangement leads to substituted methylenecyclopropanes in good to excellent yields (42-99%) [Eq. (1); X = C (n = 3), N (n = 2), O (n = 1)]. The intermediate 1,1-dimethyleneallylpalladium complex was isolated and fully characterized by an X-ray crystal-structure analysis.