Intermolecular hydrogenation of a C=C bond during π-cyclopentadienyliron complexation of 1,8-dichloro-9,10-dihydro-9,10-ethenoanthracene
Reaction of 1,8-dichloro-9,10-dihydro-9,10-ethenoanthracene with ferrocene in the presence of Al and AlCl3 in cyclohexane affords the mono-iron complex [endo-(η 6-(1,8-dichloro-9,10-dihydro-9,10-ethanoanthracene))FeCp](PF 6) as the only isolable iron-containing product. X-ray and NMR analysis of this product confirms that the etheno bridge in the arene ligand has been hydrogenated. The intramolecular mechanism previously proposed for this type of hydrogenation accompanying π complexation (i.e. involving an Fe-H intermediate) is impossible for steric reasons; thus, an intermolecular process must be considered. The same reaction was attempted in methylcyclohexane-cyclohexane mixtures, in order to improve the complexation yield and favor the formation of diiron complexes. However, this led instead to the formation of [(η6-toluene)FeCp](PF6), in which the coordinated toluene ligand arises from dehydrogenation of the methylcyclohexane solvent. © 1999 Elsevier Science S.A. All rights reserved.
Publication Source (Journal or Book title)
Journal of Organometallic Chemistry
Benites, M., Fronczek, F., & Maverick, A. (1999). Intermolecular hydrogenation of a C=C bond during π-cyclopentadienyliron complexation of 1,8-dichloro-9,10-dihydro-9,10-ethenoanthracene. Journal of Organometallic Chemistry, 577 (1), 24-30. https://doi.org/10.1016/s0022-328x(98)01021-3