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.