This paper is dedicated to the memory of Professor Manfred Schlosser.
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 °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 (NiBr2bipy) that does not require the preparation of sensitive organometallic intermediates. Yields are good to excellent.
Key words
aryl tosylates - biaryls - dimerization - nickel catalysis - Ullmann-type reaction