Synthesis of N‑Functionalized/NH-Multisubstituted Indoles, Thienopyrroles, Pyrroloindoles, and Pyrazolopyrroles via Sequential One-Pot Base-Mediated and Copper-Catalyzed Inter- and Intramolecular Amination of 2‑[2-Bromo(het)aryl]-3-(het)aryl-3-(methylthio)acrylonitriles

A novel,
efficient route to substituted 1-N-(het)­aryl/NH-2-(het)­aryl-3-cyanoindoles
and related pyrrolo-fused heterocycles such as thienopyrroles, pyrroloindoles,
and pyrazolopyrroles has been reported. The overall protocol involves
sequential cycloamination of readily available 2-[2-bromo­(het)­aryl]-3-(het)­aryl-3-(methylthio)­acrylonitrile
precursors with primary amines or amides via two key C–N bond-forming
processes, one base-mediated intermolecular and the other Cu-catalyzed
intramolecular arylamination leading to N(1)–C(2) and N(1)–C­(7a)
bond formation, respectively, in a two-step one-pot procedure.