Per IUPAC, the term biaryl refers to an assembly of two aromatic rings joined by a single bond, starting with the simplest, biphenyl. Biaryls constitute an important structural motif of physical organic, synthetic, and catalytic interest—for instance, underlying the area of atropisomers in enantioselective synthesis—and they appear in many pharmaceutical, agrochemical, and materials (e.g. LCD) applications. The example of a coupling reaction reaction used in their preparation is an alternative to the traditional Suzuki and Stille cross-coupling reactions, and various catalysts have been employed for this transformation; Goossen et al. reported the formation of biaryls from palladium and copper-catalzyed cross-coupling reactions of an aryl or heteroaryl carboxylic acid and an aryl halide (I, Br, or Cl) in the presence of a base.