The development of palladium catalysed aryl C–N coupling reactions employing aryl halides as substrates has had an enormous impact on synthetic chemistry. The wide range of N-based coupling partners, the ability to employ iodo-, bromo-, chloro- and sulfonate-substituted arenes as substrates, together with the availability of commercial catalysts are all responsible for the popularity and utility of this class of transformation. 1 More recently, copper-based ...