HFIP-mediated C-3-alkylation of indoles and synthesis of indolo[2,3-b]quinolines & related natural products.

An expeditious metal free C-3 alkylation of indoles and its NIS-mediated deviation to indolo[2,3-b]quinolines is reported. This protocol, executed in aqueous HFIP has broad substrate scope and is well inclined towards the ideas of sustainable chemistry. Applications of these strategies in accessing bioactive natural products like vibrindole, norcryptotakeine, neocryptolepine and indenoindolone scaffolds has also been demonstrated.