Cobalt- and iron-catalyzed redox condensation of o-substituted nitrobenzenes with alkylamines: a step- and redox-economical synthesis of diazaheterocycles.
A wide variety of functionalized 2-aryl benzimidazoles can be prepared by a solvent-free cobalt- or iron-catalyzed redox condensation of 2-nitroanilines and benzylamines. The cascade including benzylamine oxidation, nitro reduction, condensation, and aromatization occurs without any added reducing or oxidizing agent. The method can be extended to other alkylamines as reducing components or 2-nitrobenzamides as oxidizing components when using an iron/sulfur catalyst to afford various diazaheterocycles.
Centre de Recherche de Gif-sur-Yvette, Institut de Chimie des Substances Naturelles, CNRS , 91198 Gif-sur-Yvette Cedex, France.
Thanh Binh
TB
Nguyen
Julie Le
JL
Bescont
Ludmila
L
Ermolenko
Ali
A
Al-Mourabit
D000588:Amines / Q000737:chemistry*; D001372:Aza Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D002384:Catalysis; D003035:Cobalt / Q000737:chemistry*; D006571:Heterocyclic Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D007501:Iron / Q000737:chemistry*; D015394:Molecular Structure; D009578:Nitrobenzenes / Q000737:chemistry*; D010084:Oxidation-Reduction
D000588:Amines; D001372:Aza Compounds; D006571:Heterocyclic Compounds; D009578:Nitrobenzenes; D003035:Cobalt; D007501:Iron