An efficient photocatalyst‐free visible light enabled synthesis of substituted pyrroles from α‐keto vinyl azides (readily prepared via Knoevenagel condensation of phenacyl azides with 2‐oxo‐2H‐chromene‐3‐carbaldehydes) was developed. The reaction proceeds through a denitrogenative photodecomposition of α‐keto vinyl azides, 1,3‐amino group migration, and coupling of intermediates with secondary amines.magnified image

Photo-decomposition of vinyl azides into corresponding (E)-stilbenes via neighboring amino group assisted ring opening of 2H-azirines, 1,2-acyl migration and enolization.

1,8‐Diazabicyclo [5.4.0]undec‐7‐ene (DBU) mediated annulation of 4‐(benzylthio/arylthio)‐2‐oxo‐2H‐chromene‐3‐carbaldehydes with phenacyl azides for the synthesis of biologically relevant pyrrolocoumarins was developed. This operationally simple and unique synthetic strategy allows the formation of desired pyrrolocoumarin in good yields (67‐84 %), and generates a new C−C and C−N bond in the overall process.