Visible-Light-Mediated Decarboxylative Alkylation Cascade Cyano Insertion/Cyclization of <i>N</i>‑Arylacrylamides under Transition-Metal-Free Conditions

The visible-light-mediated decarboxylative functionalization of aliphatic carboxylic acids using organocatalysts has rarely been reported. This study represented an environmentally benign decarboxylation method involving the combination of eosin Y and (NH₄)₂S₂O₈. This system converted aliphatic carboxylic acids to alkyl radicals, followed by their addition to the carbon–carbon double bond of the <i>N</i>-arylacrylamide cascade cyano insertion/cyclization to construct alkylated phenanthridines in moderate to good yields under photoredox catalysis