Mechanism of the catalytic transformation of cyanopyridine isomers into pyridinecarboxamide isomers by magnesium phthalocyanine

► Three intermediate MgPc-complexes with 2-, 3- and 4-pyridiniecarboxamide are isolated. ► X-ray diffraction study of MgPc-complexes shows 4 + 1 O-coordination of Mg centre. ► In the MgPc-derivative the 4-pyridiniecarboxamide acts as an O,N-bridging ligand. ► The MESP maps are helpful to explain the transformation mechanism of CN into amide group.