Palladium(II)-catalyzed ortho-arylation via phosphate-group-directed C-H activation

Aryl dialkyl phosphate, which is readily available from phenol, was a good substrate for the Pd(II) catalyzed aryl-aryl coupling reaction through ortho-C-H activation. Although a phosphate group is regarded as a poor coordinating group, highly regioselective ortho-arylation could be achieved by employing Pd(OTf)2·2H2O and Ar2IOTf as a catalyst and an aryl group source, respectively. The phosphate group of the resulting coupled product can be transformed into an aryl anion via reductive cleavage and used for further C-C bond formation.