Catalytic Oxidative Coupling Cyclization for Construction of Benzofuroindolenines under Mild Reaction Conditions

We describe iron-catalyzed oxidative coupling cyclization of tetrahydrocarbazoles or TH beta Cs or TH gamma Cs to form benzofuroindolenines as fused polycyclic indoles. This mild, efficient and simple approach afforded a library of more than 52 complex compounds across a range of substrate classes with good to excellent yields.