A facile, one-pot synthesis of 1H-indazoles featuring a Cu-catalyzed C-H ortho hydroxylation and N-N bond formation using pure oxygen as terminal oxidant is described.  Reaction of readily available 2-arylaminobenzonitriles with various organometallic reagents led to ortho-arylamino N-H ketimine species.  Subsequent Cu-catalyzed hydroxylation at ortho-position of the aromatic ring followed by N-N bond formation in DMSO under pure oxygen afforded a wide variety of 1-(ortho-hydroxylaryl) 1H-indazoles in good to excellent yields.  The efficient methodology does not require utilization of noble metal catalysts, elaborated directing groups and privileged ligands.

[1] C.-y. Chen, G. Tang, F. He, Z. Wang, H. Jing, R. Faessler, Org. Lett. 2016, 18, 1690.