HYDROGEN ELIMINATION IN CYCLOPENTADIENYLNICKEL COMPOUNDS AS A ROUTE TO ORGANONICKEL AND ORGANIC-COMPOUNDS

Reactions of alpha-, beta- and gamma-hydrogen elimination in cyclopentadienylnickel compounds formed in the reactions of nickelocene with lithium or magnesium compounds are discussed. Elimination of alpha-hydrogen from CpNiR where R is CH3, CH2C(CH3)(3), CH2Si(CH3)(3), CH(2)Ph or CH=C(CH3)(2) leads to the formation of trinickel clusters (CpNi)(3)CR', bis(cyclopentadienyl)(mu-cyclopentadienyl)dinickel and (eta(5)-cycropentadienyl)(eta(3)-cyclopentenyl)nickel. beta-Hydrogen and gamma-hydrogen elimination in vinylnickel compounds not posessing alpha-hydrogen have been studied. Elimination and transfer of hydrogen forms (eta(3)-allyl)(eta(5)-cyclopentadienyl)nickel compounds. The mechanisms of these reactions are discussed.