The prevalence of the biaryl structural motif in biologically interesting and synthetically important molecules has inspired considerable interest in the development of methods for aryl-aryl bond formation. Herein we describe a novel strategy for this process involving the fluoride-free, palladium-catalysed cross-coupling of readily accessible aryldisiloxanes and aryl bromides. Using a statistical-based optimisation process, preparatively useful reaction conditions were formulated to allow the cross-coupling of a wide range of different substrates. This methodology represents an attractive, cost-efficient, flexible and robust alternative to the traditional transition-metal-catalysed routes typically used to generate molecules containing the privileged biaryl scaffold.

We describe herein two alternative protocols to efficiently prepare difluoromethylgold(I) complexes bearing ancillary ligands with different electronic and steric properties. LAu−OX (X = H and t-Bu) species, formed in the presence of base, have been identified as intermediate complexes involved in these transformations. The application of these compounds as "CF 2 H transmetalation shuttles" from gold to palladium has been demonstrated in a Pd-catalyzed difluoromethylation reaction of aryl iodides, in which the Au-to-Pd transfer of "CF 2 H" is feasible under stoichiometric conditions. These findings will pave the way for catalytic manifolds in gold chemistry.