nickel the reaction mixture can comprise excess amine ligand in an amount of about 0 1 to about 10 moles per mole of nickel specifically about 0 2 to about 5 moles per mole of nickel more specifically about 1 to about 2 moles per mole of nickel in other words in these embodiments the molar ratio of nickel to total amine ligand is about 1 1 1 to about 1 1 1 in some embodiments the nickel amine complex comprises a bisphosphine ligand in addition to a nickel atom and an amine ligand suitable bisphosphine ligands include for example 1 2 bis diphenylphosphino ethane 1 3 bis diphenylphosphino propane 1 2 bis dicyclohexylphosphino ethane 1 3 bis dicyclohexylphosphino propane and the like and mixtures thereof in some embodiments the nickel amine complex comprises 1 3 bis diphenylphosphino propane in some embodiments the nickel amine complex comprises 2 2 u2032 bipyridine and 1 3 bis diphenylphosphino propane the nickel amine complex may be provided in its active form for example as ni 1 3 bis diphenylphosphino propane 2 2 bipyridine however it is often more convenient to generate the nickel complex from a catalyst precursor for example the nickel amine catalyst may be generated from catalyst precursors comprising 2 2 u2032 bipyridine and a nickel complex selected from the group consisting of ni 1 3 bis diphenylphosphino propane cl 2 ni 1 2 bis diphenylphosphino ethane cl 2 and mixtures thereof in some embodiments the nickel complex is ni 1 3 bis diphenylphosphino propane cl 2 while not wishing to be bound by any particular mechanistic theory the present inventors speculate that the alkyl lithium may also contribute to formation of the active catalyst from the catalyst precursors a major advantage of the present.