NaHS·<i>n</i>H₂O-induced umpolung: the synthesis of 2-acyl-3-aminoindoles from aryl methyl ketones and 2-aminobenzonitriles

Abstract

An efficient method for constructing 2-acyl-3-aminoindoles from methyl ketones and 2-aminobenzonitriles is described, in which NaHS·nH2O is used as a novel umpolung reagent for the first time in organic synthesis. Mechanistic studies revealed that the key step involved an Eschenmoser sulfide contraction reaction.