Regioselective synthesis of indole-annulated sulfur heterocycles by tri-n-butyltin hydride-mediated aryl radical cyclization

Synthesis of indole-annulated sulfur heterocycles using copper-catalysed C–N coupling and palladium-catalysed direct arylation

A simple and efficient method for the synthesis of biologically relevant 5H-benzo[4,5][1,3]thiazino[3,2-a]indoles and 5,7-dihydroisothiochromeno[3,4-b]indoles has been developed via intramolecular copper catalysed Ullmann-type C–N coupling and palladium catalysed direct arylation.

One-pot double intramolecular homolytic aromatic substitution routes to dialicyclic ring fused imidazobenzimidazolequinones and preliminary analysis of anticancer activity

Bu(3)SnH/1,1'-azobis(cyclohexanecarbonitrile) (ACN)-mediated five, six, and seven-membered double alkyl radical cyclizations onto imidazo[5,4-f]benzimidazole and imidazo[4,5-f]benzimidazole are described. The quinone derivatives evaluated show selective toxicity towards human cervical (HeLa) and prostate (DU145) cancer cell lines (with negligible toxicity towards a normal human cell line, GM00637). Only the Fremy oxidation of the 6-aminoimidazo[5,4-f]benzimidazole gave iminoquinone, which showed high specificity towards the prostate cancer cell line (DU145).