Dimerization of Aryl Sulfonates by in situ Generated Nickel(0)

A mild and user-friendly nickel-catalyzed method for the reductive homocoupling of aromatic tosylates is presented. The reaction proceeds between room temperature and 60 degrees C, with stable substrates (ArOTs) easily prepared from inexpensive and commercially available phenols or naphthols. It relies on a catalytic amount (10 mol%) of a robust catalyst (NiBr(2)bipy) that does not require the preparation of sensitive organometallic intermediates. Yields are good to excellent.