N. Novikova et al., OXIDATION OF IENYLCYCLOHEXADIENYL)(ETA(5)-CYCLOPENTADIENYL)IRON BY TRITYL HEXAFLUOROPHOSPHATE, Russian chemical bulletin, 46(5), 1997, pp. 1007-1009
Oxidation of the cyclohexadienyl complex Fe(eta(5)-C5H5)(1-5-eta(5)-6-
exo-C5H5-C6H6) (2) by (Ph3C)PF6 (CH2Cl2, from similar to 30 to +20 deg
rees C) occurs as two concurrent processes: elimination of an H atom f
rom the cyclohexadienyl ligand and replacement of an H atom in the cyc
lopentadienyl ring by a CPh3 fragment. A mixture of cationic complexes
[Fe(eta(5)-(CH5)-H-5)(eta(6)-Ph-C5H5](+) (1(+)) and [Fe(eta(5)-C5H4CP
h3)(eta(6)-Ph-C5H5)](+) (4(+)) with PF6- anions is obtained. Deprotona
tion of the mixture of 1(+) and 4(+) complexes under the action of (Bu
OK)-O-t in m-xylene followed by boiling of the reaction mixture gives
phenylferrocene (7) as the product of eta(6):eta(5)-interring haptotro
pic rearrangement.