Generation of Pd Nanoparticles in situ from PdCl2 in TBAF: An Efficient and Reusable Catalytic System for the Suzuki-Miyaura Reaction under Ligand- and Solvent-free Conditions

Pd nanoparticles were generated in situ from PdCl2 in TBAF (n-Bu4NF), which displayed high efficiency for the Suzuki-Miyallra cross-coupling reaction. In the presence of PdCl2 and TBAF, a variety of aryl halides were coupled with arylboronic acids smoothly in moderate to good yields. Moreover, the PdCl2/TBAF system could be recovered and reused several times in the Suzuki-Miyaura reaction, and aryl bromides could be consumed completely by arylboronic acids in about 15-60 min. It is noteworthy that these reactions were conducted under solvent-free, ligand-free and reusable conditions. Mechanism for the PdCl2/TBAF-catalyzed reactions was also discussed.