One-pot synthesis of <i>trans</i> -2,3-diaminoindolines through 2,3-diamination of electrophilic indolines

Despite recent advances in the synthesis of 2,3-diaminoindole derivatives, construction of 2,3-diaminoindolines, whose two amine moieties on each molecule differ from one another has yet to be achieved. In this work, we developed a concise one-pot protocol for differentiated diamination involving reacting a C2,C3-electrophilic indole reagent with amines to access a variety of previously inaccessible 2,3-diaminoindolines. Furthermore, the synthetic utility of this protocol was demonstrated by a successful gram-scale reaction and further transformation of the 2,3-diaminoindolines.