Synthesis of 2‐(Oxindol‐3‐yl)acetamides via Visible‐light‐mediated Oxidative Carbamoylation of N‐arylacrylamides

Abstract Under metal free condition, an efficient and mild cascade reaction of N ‐arylacrylamides with hydrazinecarboxamides is disclosed. Catalyzed by Rose Bengal, it undergoes oxidative dehydrazination, radical addition, and subsequent 5‐exo‐trig cyclization in the presence of visible light. A series of 2‐(oxindol‐3‐yl)acetamides are obtained in moderate to excellent yields, which could be utilized as precursors in the synthesis of bioactive pyrrolidinoindolines.