Blue LED-driven C-N Bond formation for Synthesis of Imidazopyridines

Abstract

The formation of C-N bonds has emerged as a powerful key for structural modifications in organic synthesis. Although transition metal-free provides a viable protocol to construct hetero molecules. The use of costly catalysts and high temperatures has limited universal applicability. Moreover, radical-based C-N bond formation without the assistance of a transition metal catalyst has been a great challenge. Here we reported the Blue LED-driven transition metal-free strategy for C-N bond formation. This reaction features easy-to-handle, mild reaction condition reactants, and good functional group tolerance. The mechanistic investigation suggests that this strategy proceeds through phenacyl bromide radical precursor and NBS mediated by H₂O to construct IPs.