Metal-Free C(sp3)-H Azidation in a Radical Strategy for the Synthesis of 3-Azido-2-oxindoles at Room Temperature.

A novel and environmentally attractive C(sp3)-H azidation of 2-oxindoles involving the formation of a C-N bond was developed. This methodology achieved for the first time 3-azido-2-oxindole construction under metal-free conditions at room temperature via a radical strategy. PhI(OAc)2 was used as the oxidant and Et3N was used as the additive in this transformation. Furthermore, the mechanistic study indicated that this azidation involved a radical process.