Hydrogenation du naphtalene et de l'anthracene lors de la complexation aux greffons cationiques C 5H 5Fe + et C 5Me 5Fe +.

Abstract

In order to investigate the mechanism of hydrogenation of polyaromatics during ligand exchange with a cyclopentadienyl ring of ferrocene, the influences of temperature, presence of aluminium powder, water, amount and quality of aluminium chloride have been examined for the reaction: ferrocene + naphthalene → CpFe + naphthalene/CpFe + tetralin. The reaction of CpFe(CO) 2Cl is analogous to that of ferrocene. The data are discussed in terms of a possible electron-transfer mechanism generating CpFe I polyaromatic and further H atom abstraction. The new pentamethylcyclopentadienyliron analogues have been synthesized and the extent of hydrogenation corresponds with the parent series. However, with anthracene, the major product of the reaction with C 5Me 5Fe(CO) 2Br in the presence of AlCl 3, η 5-C 5Me 5Fe +-η 6-1,2,3,4-tetrahydroanthracene results in the change of hydrogeneration site.