Visible light-driven azidation of vinyl arenes with azidobenziodoxole as the azidating agent was investigated in acetonitrile by using Cu­(I)­(phenanthroline)2 complex [Cu­(dap)2]­PF6 as photocatalyst. The reactions generated three types of difunctionalization products, which correspond to reaction patterns of amido-azidation, benzoyloxy-azidation, and diazidation. The electronic nature of the aryl group attached to the olefin moiety was found to play a crucial role in determining the reaction consequence: when the aryl group was electron-rich, the reactions afforded benzoyloxy-azidation products exclusively; for highly electron-deficient vinyl arenes, by contrast, diazidation products were generated in moderate yields. When the aryl group was moderately electron-rich or electron-deficient, on the other hand, a three-component reaction involving acetonitrile as well as azidobenziodoxole took place to give predominantly amido-azidation products. A plausible mechanism is proposed based on the mechanistic studies to rationalize these results. The reactions of electronically less biased vinyl arenes probably proceed via a redox catalysis pathway, while the electron-rich alkenes are believed to be converted through a radical chain process. The present reactions may be of synthetic usefulness as they provide a new means for the amido-azidation of vinyl arenes.

Synthesis of enamides via 1,2-acyl migration of tertiary α-azido ketones was accomplished efficiently by the catalysis of FeBr2 and Et3N.

This paper reports two new visible-light-promoted radical reactions of α-azido amides. By catalysis of [Ir­(ppy)2(dtbbpy)]­PF6 with i-Pr2NEt as the reducing agent, N-aryl α-azido tertiary amides were first converted to the corresponding aminyl radicals through reduction of the azido group; the aminyl radicals then underwent N-to-N aryl migration to give α-anilinyl-functionalized amides. α-Azido secondary amides, on the other hand, reacted with the solvent ethanol and i-Pr2NEt to afford the imidazolinone products.