NHC-catalyzed oxindole synthesis via single electron transfer

A transition-metal and aldehyde free, NHC-catalyzed, redox-neutral oxindole synthesis method is disclosed. This protocol has a broad substrate scope and good functional group tolerance and could be smoothly scaled up to a gram scale. The reaction possibly undergoes NHC-facilitated single electron transfer induced intramolecular radical cyclization. The oxindole products could be easily converted into many different useful compounds. The power of this reported method is further examined by the rapid and efficient synthesis of two bioactive molecules.