Pd-Catalyzed Regioselective Tandem Heck/C–H Activation/Bisamination Reactions with Ynamides and Diaziridinone. Rapid Access to 3-Aminoindoles

This work describes a highly efficient Pd-catalyzed annulation process of aryl iodides, ynamides, and di-tert-butyldiaziridinone. A wide variety of 3-aminoindoles bearing various functional groups have been readily obtained in up to 99% yield. 3-Aminoindole functionalities can also be easily introduced into medicinally important molecules. The reaction likely proceeds through a sequential regioselective Heck reaction and aryl C-H activation to form a pallada(II)cycle species, which is bisaminated with diaziridinone via a pallada(IV)cycle intermediate. The resulting 3-aminoindoles can serve as versatile precursors for the construction of structurally diverse aza-polycyclic compounds.