Iron-catalyzed three-component 1,2-azidoalkylation of conjugated dienes via activation of aliphatic C–H bonds

Abstract

Azidoalkyation is an efficient strategy for the conversion of unsaturated precursors into nitrogen-containing structural motifs. Herein, we describe a convenient and highly regioselective iron-catalyzed 1,2-azidoalkylation of 1,3-dienes that employs TMSN₃ as a coupling partner with hydrocarbons that bear diverse C–H bonds. This chemistry is achieved through the direct functionalization of strong C(sp³)–H bonds and is facilitated by a combination of hydrogen atom transfer (HAT) and iron catalysis. Notably, the protocol operates with catalyst loadings as low as 0.2 mol% and furnishes access to versatile β-unsaturated azido products with high levels of site-, regio-, and stereoselectivities. Mechanistic studies suggest that the reaction proceeds via a radical pathway; depending on the electronic properties of the diene, the allylic radical intermediate may engage through either group transfer or a single electron oxidation process.