Effective Pd-nanoparticle (PdNP)-catalyzed Negishi coupling involving alkylzinc reagents at room temperature

Pd(OAc)(2) is an efficient catalyst precursor for Negishi coupling in the presence of Bu4NBr. Secondary and primary alkylzinc reagents with beta-H and arylzinc reagents all reacted with aryl iodides at temperatures as low as -20 degrees C, giving moderate to good yields. One example of coupling between alkynylzinc reagents and aryl iodides was tested and the yield was good. Preliminary kinetic studies indicated that the process involved PdNPs as the active catalytic species.