The cross-dehydrogenative coupling (CDC) of two unfunctionalized arenes is one of the most attractive transformations to build up the ubiquitous biaryl motif.[1, 2] In comparison to established cross-coupling reactions between aryl halides and organometallic reagents,[3] CDC is considered a more efficient and environmentally friendly approach since it circumvents the often tedious and wasteful prefunctionalization of starting materials. ...