Merging Hydrogen Atom Transfer and Halogen Atom Transfer for Iodide-Catalyzed Radical Reductive Cyclization of 1,6-Enynes.

Described herein is the development of a metal-free iodide-catalyzed radical reductive cyclization of 1,6-enynes. A strategy involving in situ iodination/radical cyclization/silyl radical-mediated halogen atom transfer/hydrogen atom transfer for the synthesis of functionalized pyrrolidines has been proposed. Using this halogen-atom abstraction protocol, 1,6-enynes with various vinyl halides including inert fluorides, chlorides, and reactive bromides could be transformed into substituted pyrroles via a multistep radical isomerization process.