Catalytic oxidations using ruthenium porphyrins - Advances in Catalytic Activation of Dioxygen by Metal Complexes - page 45

elemental analysis and a magnetic moment showing 2 unpaired electrons.
More detailed studies have shown subsequently that the product is, in
fact, ( 24 in Fig. 22 below) 65 . ( 24 ) was synthesized
independently from the metathesis reaction between with
excess phenol under Ar, and mass spectral data distinguished the product
from the supposed ( 23 ), which was probably the dihydrate of ( 24 ). A revised
mechanism for the stoichiometric phenol oxidation is presented in Figure 22.
The reaction initially produces p -hydroquinone, which is further oxidized to
p -benzoquinone at a rate faster than the rate of phenol oxidation, and this
was confirmed by direct oxidation of p -hydroquinone with
The generated species is then thought to react reversibly with water
to give the dihydroxy species (the X-ray structure for
has been reported 164 ) that then undergoes metathesis with