Nanocrystalline magnesium oxide-stabilized palladium(0): An efficient and reusable catalyst for Suzuki and Stille cross-coupling of aryl halides

A nanocrystalline magnesium oxide-stabilized palladium(0) catalyst is prepared by counterion stabilization of PdCl42- with nanocrystalline MgO followed by reduction. This ligand-free heterogeneous nanocrystalline MgO-stabilized nanopalladium [NAP-Mg-Pd(0)] catalyst using the basic MgO in place of basic ligands exhibits excellent activity in Suzuki and Stille cross-coupling of haloarenes (chloro, bromo and iodo) to afford the unsymmetrical biaryls. The catalyst is quantitatively recovered by simple filtration and reused for four cycles with almost consistent activity.