Process for the catalytic reversible unsaturated-hydrocarbon - nitrile interconversion wherein an unsaturated hydrocarbon is reacted with a nitrile compound in the presence of a transition metal coordinated to a ligand and a Lewis acid co-catalyst, preferably in a solvent, to yield a nitrile compound and an unsaturated hydrocarbon, each being different from the starting compounds, as represented in the following reaction scheme: wherein: - R 1, R 2, R 3 and R 4 can be the same or different and each independently represents H, a heterosubstituent, straight chain or branched chain alkyl, cycloalkyl, heterocycloalkyl, aryl, aralkyl, heteroaryl, heteroaralkyl, each being optionally substituted by one or more groups selected from straight chain or branched chain alkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl, aralkyl, heteroaryl, heteroaralkyl or a heterosubstituent; or at least two of R 1, R 2, R 3 and R 4 may each form a cyclic 3 to 20 membered ring structure which may further be substituted by one or more groups selected from straight chain or branched chain alkyl, cycloalkyl, heterocycloalkyl, aryl, aralkyl, heteroaryl, heteroaralkyl or a heterosubstituent, and optionally including any of O, S, N in the straight chain, branched chain or cyclic structure; or R 2 and Reform a bond; wherein at least one of R 1, R 2, R 3 and R 4 is not hydrogen; - R 5, R 6, R 7 and R 8 can be the same or different and each independently represents H, a heterosubstituent, straight chain or branched chain alkyl, cycloalkyl, heterocycloalkyl, aryl, aralkyl, heteroaryl, heteroaralkyl, each being optionally substituted by one or more groups selected from straight chain or branched chain alkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl, aralkyl, heteroaryl, heteroaralkyl, or a heterosubstituent, or at least two of R 5, R 6, R 7 and R 8 may each form a cyclic 3 to 20 membered hydrocarbon ring structure which may further be substituted by one or more groups selected from straight chain or branched chain alkyl, cycloalkyl, heterocycloalkyl, aryl, aralkyl, heteroaryl, heteroaralkyl or a heterosubstituent, and optionally including any of O, S, N in the straight chain, branched chain or cyclic structure; wherein preferably at least one of R 5, R 6, R 7 and R 8 is not hydrogen; - the metal of the coordinated transition metal catalyst is selected from Ni or Pd; - the ligand of the coordinated transition metal catalyst is selected from phosphine ligands; and - the Lewis acid co-catalyst is selected from AlMe 3, AlMe 2 Cl, AlMeCl 2 or AlCl 3. - R 1, R 2, R 3 and R 4 can be the same or different and each independently represents H, a heterosubstituent, straight chain or branched chain alkyl, cycloalkyl, heterocycloalkyl, aryl, aralkyl, heteroaryl, heteroaralkyl, each being optionally substituted by one or more groups selected from straight chain or branched chain alkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl, aralkyl, heteroaryl, heteroaralkyl or a heterosubstituent; or at least two of R 1, R 2, R 3 and R 4 may each form a cyclic 3 to 20 membered ring structure which may further be substituted by one or more groups selected from straight chain or branched chain alkyl, cycloalkyl, heterocycloalkyl, aryl, aralkyl, heteroaryl, heteroaralkyl or a heterosubstituent, and optionally including any of O, S, N in the straight chain, branched chain or cyclic structure; or R 2 and Reform a bond; wherein at least one of R 1, R 2, R 3 and R 4 is not hydrogen; - R 5, R 6, R 7 and R 8 can be the same or different and each independently represents H, a heterosubstituent, straight chain or branched chain alkyl, cycloalkyl, heterocycloalkyl, aryl, aralkyl, heteroaryl, heteroaralkyl, each being optionally substituted by one or more groups selected from straight chain or branched chain alkyl, cycloalkyl, heterocycloalkyl, alkenyl, alkynyl, aryl, aralkyl, heteroaryl, heteroaralkyl, or a heterosubstituent, or at least two of R 5, R 6, R 7 and R 8 may each form a cyclic 3 to 20 membered hydrocarbon ring structure which may further be substituted by one or more groups selected from straight chain or branched chain alkyl, cycloalkyl, heterocycloalkyl, aryl, aralkyl, heteroaryl, heteroaralkyl or a heterosubstituent, and optionally including any of O, S, N in the straight chain, branched chain or cyclic structure; wherein preferably at least one of R 5, R 6, R 7 and R 8 is not hydrogen; - the metal of the coordinated transition metal catalyst is selected from Ni or Pd; - the ligand of the coordinated transition metal catalyst is selected from phosphine ligands; and - the Lewis acid co-catalyst is selected from AlMe 3, AlMe 2 Cl, AlMeCl 2 or AlCl 3.