Synthesis of 1-Indazoles via Silver(I)-Mediated Intramolecular Oxidative C-H Bond Amination.

We described a silver(I)-mediated intramolecular oxidative C-H amination that enables the construction of assorted 1-indazoles that are widely applicable in medicinal chemistry. The developed amination was found to be efficient for the synthesis of a variety of 3-substituted indazoles that are otherwise difficult to be synthesized by other means of C-H aminations. Preliminary mechanistic studies suggested that the current amination proceeds via single electron transfer (SET) mediated by Ag(I) oxidant.