TRANSITION METAL ALKYLS AND HYDRIDES .8. NICKEL CHLORIDE CATALYZED INSERTION OF ETHYLENE INTO ARYLMAGNESIUM HALIDES

Anhydrous nickel chloride catalyses the insertion of ethylene into the CMg-bond of arylmagnesium bromides and also the subsequent alkylolefin exchange reaction of the primary aralkyl metal derivatives. Other transition metal halides are less active. (2-Phenylethyl)magnesium bromide isomerises under these conditions to the 1-isomer, and this isomerization is promoted by olefins. The nickel catalyst complex probably contains both σ-alkyl (aralkyl or aryl) and π-olefin ligands, and direct hydride migration between these ligands is proposed as the mechanism for the exchange and isomerization in the presence of certain olefins. © 1969.