New Chemical Synthesis of Functionalized Arylzinc Compounds from Aromatic or Thienyl Bromides under Mild Conditions Using a Simple Cobalt Catalyst and Zinc Dust

A new chemical method for the preparation of arylzinc intermediates is described in acetonitrile, on the basis of the activation of aryl bromides by low-valent cobalt species arising from the reduction of cobalt halide by zinc dust. This procedure allows for the synthesis of a variety of functionalized aryl- and thienylzinc species in good to excellent yields. The versatility and the simplicity of that original method represent an alternative to most known procedures.