Bronze Age of Direct Mechanocatalysis: How Alloyed Milling Materials Advance Coupling in Ball Mills

The copper‐catalyzed Glaser coupling is conducted mechanochemically, with the milling balls and vessels being the catalyst. Thus, neither catalyst powders nor soluble catalyst salts are required. Substituting Cu 0 milling tools by copper alloys not only increases the yield of the reaction, but also greatly reduces abrasion, and in turn increases catalyst long‐term stability and reusability. Tracking the reaction by Raman spectroscopy allows to identify the active intermediate directly on the milling ball surface and propose a reaction mechanism.