L. Porri

The reaction of allene with β-diketonatorhodium(I) complexes: Formation of bis(π-allylic) complexes of rhodium(III) and of rhodacyclopentane derivatives

The reaction of allene with complexes of the type (β-diketonato)Rh(C2H4)2 at temperatures between −30 and +20°, gives RhIII derivatives of formula (β-diketonato)Rh(C3H4)4, in which an allene tetramer is bonded to rhodium by two π-allylic groups. The molecular structures of these complexes were determined on the basis of the chemical behaviour, IR and NMR spectra, and, for one of them, also by X-ray examination. The reaction of (Acac)Rh(C2H4)2 with allene at −78° yields new rhodium(III) derivatives containing the 3,4-dimethylenerhodacyclopentane moiety. These are precursors of the bis(π-allylic) complexes. The mechanism of formation of the rhodium(III) complexes is briefly discussed.

π-allylnickel complexes from conjugated diolefins and nickel halides

Abstract Some π-allylnickel derivatives were prepared in good yield and under mild conditions from the reaction of conjugated dienes and nickel halides in the presence of metallic zinc.

The reaction of allene with dicarbonylchlororhodium: Formation of new π-allylic complexes of rhodium(III)

Abstract The reaction of allene with [Rh(CO)2Cl]2 to give a new π-allylic complex of rhodium(III) containing an allene dimer is described; the reactions of this complex with PPh3 and AsPh3 are reported.