Investigation of the Synthesis of Benzofuroindolines from N-Hydroxyindoles: An O-Arylation/[3,3]-Sigmatropic Rearrangement Sequence

Abstract

We report the demonstration that sensitive <i>N</i>-hydroxyindoles can be O-arylated under transition-metal-free conditions with biaryliodonium salts. The subsequent spontaneous [3,3]-sigmatropic rearrangement delivers benzofuroindolines derived from tryptamine. We also describe the practical synthesis of <i>N</i>-hydroxyindoles by oxidation of indolines with <i>m</i>-CPBA.