Biaryls constitute an important structural component in natural products, pharmaceuticals, agrochemicals and materials. 1 In recent decades there have been rapid advances in C(sp 2 )–C(sp 2 ) bond formation reactions to construct biaryls. Traditionally, the arene being coupled needs to be 'pre-activated', such as by halogenation, prior to metal-mediated coupling reactions. 2 Alternatively, halogenated arenes are converted to organometallic reagents and homo- or ...