Self-Assembled Organometallic Nickel Complexes as Catalysts for Selective Dimerization of Ethylene into 1-Butene

Sulfonamido-phosphorus and aminophosphine ligands self-assemble to readily form active and stable nickel catalysts that are highly selective for the dimerization of ethylene to 1-butene. The self-assembled allyl-nickel complexes are zwitterionic and are stabilized by hydrogen bond interactions between the two ligands. These organometallic cis-diphosphine complexes rearrange under an ethylene atmosphere to give trans-diphosphine catalysts, with one monoanionic P,O METAMORPhos ligand and an aminophosphine.