RESUMO
A general, straightforward, and atom-economical three-component synthesis of thioamides from alkynes, elemental sulfur, and aliphatic amines has been developed.
Assuntos
Alcinos/química , Aminas/química , Enxofre/química , Tioamidas/síntese química , Estrutura Molecular , Tioamidas/químicaRESUMO
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.
Assuntos
Aminas/química , Compostos Aza/síntese química , Cobalto/química , Compostos Heterocíclicos/síntese química , Ferro/química , Nitrobenzenos/química , Compostos Aza/química , Catálise , Compostos Heterocíclicos/química , Estrutura Molecular , OxirreduçãoRESUMO
Iron sulfide generated in situ from elemental sulfur and iron was found to be highly efficient in catalyzing a redox/condensation cascade reaction between 2-amino/hydroxy nitrobenzenes and activated methyl groups. This method represents a straightforward and highly atom economical approach to 2-hetaryl-benzimidazoles and -benzoxazoles.