A method for the creation of a carbon-carbon (C-C) bond or of a carbon-heteroatom (C-HE) bond by reacting a compound carrying a leaving group with a nucleophilic compound carrying a carbon atom or a heteroatom capable of replacing the leaving group, thus creating a C-C or C-HE bond, in which process the reaction is carried out in the presence of an effective amount of a catalytic system comprising at least one copper/butadienylphosphine complex, the copper/butadienylphosphine complex being a complex comprising copper and at least one butadienylphosphine of formula: in which: • R a and R b, identical, each represent a radical chosen independently from alkyl comprising 1 to 10 carbon atoms, phenyl, naphtyl, dialkylamino comprising 1 to 10 carbon atoms, alkoxy comprising 1 to 10 carbon atoms, phenyloxy, naphtyloxy; • R 1, R 2, R 3, which are identical or different, are chosen independently from hydrogen, a hydrocarbon radical comprising 1 to 20 carbon atoms; • R 4 and R 5, which are identical or different, are chosen independently from hydrogen, hydrocarbon radical comprising 1 to 20 carbon atoms, phenyl, naphtyl; the compound carrying a leaving group is chosen among the compounds of formula Y-R 0, in which formula Y represents a leaving group and R 0 represents a hydrocarbon group comprising from 2 to 20 carbon atoms and at least one unsaturation situated in the α position with respect to a leaving group Y or represents a monocyclic or polycyclic aromatic carbocycle and/or heterocycle group, the nucleophilic compound being chosen among: • Compounds of formula R 25 -NH-CO-R 26 in which R 25 and R 26, identical or different, are chosen among hydrogen, phenyl or naphtyl radical; • Compounds of formula in which o A represents one of the following cycle: - a monocyclic heterocycle comprising one or more heteroatoms: - a bicycle comprising a carbocycle and a heterocycle comprising one or more heteroatoms: - a tricycle comprising at least one carbocycle or one heterocycle comprising one or more heteroatoms: ∘ R 32, which are identical or differentis chosen among: - a linear or branched C 1 to C 6 alkyl group; - a linear or branched C 2 to C 6 alkenyl or alkynyl group; - a linear or branched C 1 to C 6 alkoxy or thioether group; - a cyclohexyl, phenyl or benzyl group; - a group chosen among hydroxyl, thiol, nitrile, azide, nitro, halogen or trifluoromethyl; ∘ n represents 0, 1, 2, 3 or 4; • Compounds of formula R 33 -Z, in whiche R 33 represents a phenyl or naphtyl radical, Z represents a OH group. • R a and R b, identical, each represent a radical chosen independently from alkyl comprising 1 to 10 carbon atoms, phenyl, naphtyl, dialkylamino comprising 1 to 10 carbon atoms, alkoxy comprising 1 to 10 carbon atoms, phenyloxy, naphtyloxy; • R 1, R 2, R 3, which are identical or different, are chosen independently from hydrogen, a hydrocarbon radical comprising 1 to 20 carbon atoms; • R 4 and R 5, which are identical or different, are chosen independently from hydrogen, hydrocarbon radical comprising 1 to 20 carbon atoms, phenyl, naphtyl; • Compounds of formula R 25 -NH-CO-R 26 in which R 25 and R 26, identical or different, are chosen among hydrogen, phenyl or naphtyl radical; • Compounds of formula in which o A represents one of the following cycle: - a monocyclic heterocycle comprising one or more heteroatoms: - a bicycle comprising a carbocycle and a heterocycle comprising one or more heteroatoms: - a tricycle comprising at least one carbocycle or one heterocycle comprising one or more heteroatoms: ∘ R 32, which are identical or differentis chosen among: - a linear or branched C 1 to C 6 alkyl group; - a linear or branched C 2 to C 6 alkenyl or alkynyl group; - a linear or branched C 1 to C 6 alkoxy or thioether group; - a cyclohexyl, phenyl or benzyl group; - a group chosen among hydroxyl, thiol, nitrile, azide, nitro, halogen or trifluoromethyl; ∘ n represents 0, 1, 2, 3 or 4; o A represents one of the following cycle: - a monocyclic heterocycle comprising one or more heteroatoms: - a bicycle comprising a carbocycle and a heterocycle comprising one or more heteroatoms: - a tricycle comprising at least one carbocycle or one heterocycle comprising one or more heteroatoms: - a monocyclic heterocycle comprising one or more heteroatoms: - a bicycle comprising a carbocycle and a heterocycle comprising one or more heteroatoms: - a tricycle comprising at least one carbocycle or one heterocycle comprising one or more heteroatoms: ∘ R 32, which are identical or differentis chosen among: - a linear or branched C 1 to C 6 alkyl group; - a linear or branched C 2 to C 6 alkenyl or alkynyl group; - a linear or branched C 1 to C 6 alkoxy or thioether group; - a cyclohexyl, phenyl or benzyl group; - a group chosen among hydroxyl, thiol, nitrile, azide, nitro, halogen or trifluoromethyl; - a linear or branched C 1 to C 6 alkyl group; - a linear or branched C 2 to C 6 alkenyl or alkynyl group; - a linear or branched C 1 to C 6 alkoxy or thioether group; - a cyclohexyl, phenyl or benzyl group; - a group chosen among hydroxyl, thiol, nitrile, azide, nitro, halogen or trifluoromethyl; ∘ n represents 0, 1, 2, 3 or 4; • Compounds of formula R 33 -Z, in whiche R 33 represents a phenyl or naphtyl radical, Z represents a OH group.