Visible‐Light‐Accelerated Copper(II)‐Catalyzed Regio‐ and Chemoselective Oxo‐Azidation of Vinyl Arenes

Abstract

The visible-light-accelerated oxo-azidation of vinyl arenes with trimethylsilylazide and molecular oxygen as stoichiometric oxidant was achieved. In contrast to photocatalysts based on iridium, ruthenium, or organic dyes, [Cu(dap)₂ ]Cl or [Cu(dap)Cl₂ ] were found to be unique for this transformation, which is attributed to their ability to interact with the substrates through ligand exchange and rebound mechanisms. Cu^II is proposed as the catalytically active species, which upon coordinating azide will undergo light-accelerated homolysis to form Cu^I and azide radicals. This activation principle (Cu^II -X→Cu^I +X^. ) opens up new avenues for copper-based photocatalysis.