1.1.6 Gold Dual Catalysis with Palladium, Nickel, or Rhodium

The unique intermediates accessible by exploiting the soft π-acid character of gold catalysts, make them an attractive option for dual metal catalysis reactions. Together with palladium, nickel, or rhodium, each having their own distinct character, dual catalysis with gold offers exclusive opportunities for reactivity and selectivity in installing carbon–carbon and carbon–heteroatom linkages. For instance, gold dual catalysis with palladium can be an advanced tool for cross-coupling reactions. On the other hand, unlike palladium, nickel is more readily susceptible to single-electron redox processes and hence can offer reactivity both parallel to and different from that of palladium. Another potential candidate, rhodium, is considered for dual catalysis with gold because it showcases unique reactivity such as C–H activation/transmetalation and conjugate addition. When compared to using single-metal catalyst systems, such dual-metal associations result in efficient one-pot approaches to highly regio- and stereoselective syntheses of molecules via cross couplings, cycloadditions, or rearrangements.