Tandem Wittig – Reductive annulation decarboxylation approach for the synthesis of indole and 2-substituted indoles

A simple tandem Wittig reaction-reductive decarboxylation route is established for the synthesis of indoles from commercially available o-nitrobenzaldehydes and a stable phosphorane. The method allows access to indoles in a very fast manner without involving any metal or expensive reagents or inert atmosphere. Also 2-substituted indoles are obtained which forms an important core of many biological active compounds. © 2018 Elsevier Ltd