An efficient high yielding approach for the homocoupling of aryl boronic acids

A concise, mild, and high yielding method yielding C-2- symmetric biaryls is described. The addition of Cu(II) nitrate enhances the rate and the yield of the desired biaryl products. The conditions employed have yielded a number of substituted symmetric biaryls including 1,1' and 2,2' BINAP and are useful for the producing symmetric biaryls from their corresponding aryl boronic acids.