Palladium Nanoparticle-Catalyzed Stereoretentive Cross-Coupling of Alkenyl Sulfides with Grignard Reagents

Reaction conditions allowing a stereoretentive cross-coupling of alkenyl sulfides with Grignard reagents using ligand-free Pd catalysis are discussed here. The presence of an adequately positioned OH function is a key feature that allows a Mg-promoted Lewis acid activation of the mercaptide leaving group. This easy to implement procedure actually relies on an in situ generation of stable Pd nanoparticles by simply mixing Pd2(dba)3, the Grignard reagent, and the vinyl sulfide cross-coupling partner in THF. The efficiency of this procedure has been demonstrated in a natural product total synthesis context.