Copper-catalyzed synthesis of benzo[4,5]thiazolo[3,2-a]indoles from elemental sulfur and 1-(2-iodophenyl)-1H-indoles

Abstract

Copper-catalyzed synthesis of benzo[4,5]thiazolo[3,2-a]indoles from element sulfur and 1-(2-iodophenyl)-1H-indoles is reported. Two sp2 C-S bonds are generated during the process. This is the first example of making benzo[4,5]thiazolo[3,2-a]indoles from...

Four-Component Ring-Opening Reaction of Pyrroles via C–N Bond Cleavage under Multiple Functions of Elemental Sulfur

“…First, elemental sulfur could be converted into metal sulfide A with a base (Cs 2 CO 3 ). A reacts with pyrrole iodobenzenes in the presence of CuI to give intermediate B, which may exist in equilibrium with intermediate C. 17 C subsequently reacts with sulfur to afford D. 18 D next undergoes intramolecular cyclization and aromatization to deliver intermediate E. 19 Then, nucleophilic attack of E to elemental sulfur generates F. Nucleophilic attack of dimethylamine derived from DMF 20 to F produces G. Thioamide H is obtained from G in the presence of base. Finally, reduction of H by elemental sulfur affords the final product 2a.…”