Unusual Homocoupling in the Reaction of Diorganocuprates with an Allylic Halide

The reactions of dialkyl- and diarylcuprates (R 2 CuM; M = Li, MgBr) with perfluoroallyl iodide were found to give the homocoupling products R−R as the only product of C−C bond formation. Density functional calculations revealed that the perfluoroallyl ligand, being strongly electron-withdrawing and less Lewis basic, significantly changes the electronic properties of the allylcopper(III) intermediate and acts as a spectator ligand in the reductive elimination.