The Formation of Carbon-Carbon and Carbon-Nitrogen Bonds Mediated by Organometallic Cobalt Complexes

Binuclear cobalt complexes of the general formula [CpCo(CO)R]2 (Cp = ƞ5 C5H5) have been prepared and the reactivity of these complexes has been investigated. Thermal decomposition of [CpCo(CO)(CH3)]2 in a variety of organic solvents leads to good yields of acetone (a process involving the formation of two new carbon-carbon bonds). The mechanism of this decomposition and that of analogous complexes where R = CH3CH2 and CF3CH2 has been elucidated. The carbonylation reactions of these complexes have also been examined. The reaction of either CpCo(CO)2 or [CpCo(NO)]2 with NO and a variety of olefins yields cobalt complexes containing 1, 2-dinitroso ligands which are derived from the alkene substrate. Thus two new carbon-nitrogen bonds are formed. The scope of this reaction is surveyed and methods for removal of the 1, 2-dinitroso ligand, with the newly formed carbon-nitrogen bonds intact, are investigated.