Access to 1a,6b-Dihydro-1H-benzofuro[2,3-b]azirines and Benzofuran-2-amines via Visible Light Triggered Decomposition of α-Azidochalcones.

A novel, efficient, organic process that involves a photocatalyst-free visible light triggered decomposition of α-azidochalcones, followed by intramolecular cyclization, 1,2-acyl migration, and isomerization to construct benzofuran based molecular architectures, is described. The scope and limitation of the synthetic strategy were studied by synthesizing over 30 structurally diverse benzofurans in high yields.