Cyanation of aryl halides using potassium hexacyanoferrate(ii) via direct mechanocatalysis†

A cyanation reaction was performed inside a ball mill system utilizing catalytically active milling balls, while avoiding the use of solvents and ligands. Additionally, replacing the highly toxic cyanide source with potassium hexacyanoferrate(II) leads to a safer reaction environment. Yields of up to 90% were achieved in as little as 4 hours at room temperature. The oxidative addition and transmetalation step could be observed via X-ray photoelectron spectroscopy (XPS) and powder X-ray diffraction (PXRD) analysis, respectively, giving a first indication of the mechanism of this mechanochemical reaction.