A Simple and Straightforward Approach to Quinoxalines by Iron/Sulfur-Catalyzed Redox Condensation of o-Nitroanilines and Phenethylamines

In situ generated iron sulfide from elemental sulfur and ferric chloride was found to be a highly efficient catalyst for the redox condensation cascade reaction between o-nitroanilines and 2-arylethylamines. This method constitutes a new atom-, step-, and redox-economical route to 2-arylquinoxalines.