RhIII/CuII-Cocatalyzed Synthesis of 1H-Indazoles through C-H Amidation and N-N Bond Formation

Substituted 1H-indazoles can be formed from readily available arylimidates and organo azides by Rh-III-catalyzed C-H activation/C-N bond formation and Cu-catalyzed N-N bond formation. For the first time the N-H-imidates are demonstrated to be good directing groups in C-H activation, also capable of undergoing intramolecular N-N bond formation. The process is scalable and green, with O-2 as the terminal oxidant and N-2 and H2O formed as byproducts. Moreover, the products could be transformed to diverse important derivatives.