Synthesis of 3,3-Spiroindolines via FeCl3-Mediated Cyclization of Aryl- or Alkene-Containing 3-Substituted N–Ac Indoles

• DOI: 10.1021/acs.orglett.6b00174
• Publication Date: 2016-03-25T18:44:09Z
• Authors: Raj Kumar Nandi; Régis Guillot; Cyrille Kouklovsky; Guillaume Vincent
• Keywords: Alkene; Umpolung; Annulation; Formal synthesis

We report the cyclization of 3-substituted N-acetylindoles for straightforward synthesis 3,3-spiroindolines via Friedel-Crafts reaction an appended aryl group or formal [2 + 2] cycloaddition alkene. Our strategy involves Umpolung C2═C3 bond indole nucleus during FeCl3-mediated hydroarylation annulation reactions.