The present invention concerns a process for creating a Carbon-Carbon bond (C—C) or a Carbon-Heteroatom bond (C—HE) by reacting a compound carrying a leaving group with a nucleophilic compound carrying a carbon atom or a heteroatom (HE) that can substitute for the leaving group, creating a C—C or C—HE bond, wherein the reaction takes place in the presence of an effective quantity of a. a catalytic system comprising a ligand and at least a metal-based catalyst, such a metal catalyst being chosen among iron or copper compounds proviso that only a single metal is present.