Decarboxylative Synthesis of Functionalized Oxindoles via An Iron-Initiated Radical Chain Process and Application in Constructing Diverse Fused-Indoline Heterocycles

Rapid construction of diverse fused-indoline-heterocycle (FIH) frameworks including high-value pyrroloindolines, furoindolines and thienoindolines in a two-step sequence has been described. The key to success hinges on the adoption of peresters as alpha-heteroatom alkyl radical precusors, which can smoothly react with N-arylacrylamides via a radical chain process initiated by inexpensive FeCl2 center dot 4H(2)O to afford the functionalized oxindoles, the key intermediates to FIH skeletons. The approach features operationally-simplicity, broad substrates scope and mild conditions.