Copper-Catalyzed 8‑Aminoquinoline Assisted Aryl Chalcogenation of Ferroceneamide with Aryl Disulfides, Diselenides, and Ditellurides

A synthetic
method has been developed for the synthesis of unsymmetrical
ferrocene aryl chalcogenides by C–H activation of ferroceneamide
using 8-aminoquinoline as
a directing group, aryl dichalcogenides, and copper­(II) catalyst in
the presence of silver acetate oxidant at 80 °C in DMSO. The
developed methodology is quite general and mild to access three unsymmetrical
diaryl chalcogenides (sulfide, selenide, and telluride) and also amenable
to aryl dichalcogenides with sensitive bromo, chloro, and nitro functionalities.
Further, ferrocene aryl tellurides have been obtained in moderate
yields for the first time by the developed C–H activation approach.
In the mechanistic part, it seems that the presence of a rigid chelating
directing ligand is crucial for the aryl chalcogenation reaction of
C–H bond under copper catalysis as the nonrigid bidentate directing
ligands were unsuccessful for the transformation.