Orthometallation as a strategy in Pd-mediated organic synthesis

The orthopalladated complexes are among the most representative Pd(II) compounds. They display a wide prospect of applications, but they are mainly known by their use as intermediates in metal-mediated organic synthesis. In this review we describe how palladacycles are used to build up new molecules through regioselective formation of C-halogen, C-O, C-N, C-P, C-S and C-C bonds, either under catalytic or stoichiometric conditions. This methodology is based on the selective incorporation of the Pd into the organic skeleton to be modified and subsequent reactivity of the Pd-C bond toward different substrates. In many cases this strategy is alternative or even competitive, improving standard organic methods. The most recent achievements of the last five years will be covered here, presenting only the most impressive results.