Mechanosynthesis of Sydnone-­Containing Coordination Complexes

N-Phenyl-4-(2-pyridinyl) sydnone was shown to act as a four-electron donor N,O-ligand in unprecedented coordination complexes featuring four different metallic centers (Co, Cu, Zn). Starting from various anilines, the use of ball-mill enabled efficiently the synthesis of N-arylglycines, subsequent nitrosylation and cyclization into sydnone, and further metalation.