RhII2‐Catalyzed Synthesis of α‐, β‐, or δ‐Carbolines from Aryl Azides

Abstract

Approaching all isomers: A range of α-, β- and δ-carbolinium ions are readily available from ortho-substituted aryl azides using a rhodium(II) carboxylate catalyst (see scheme). The carbolinium ions are readily reduced to afford tryptolines or deprotonated to access pyridoindoles. This [RhII2]-catalyzed CH bond amination was used in the synthesis of (±)-horsfiline and neocryptolepine. esp=α,α,α′,α′- tetramethyl-1,3-benzenedipropionate.