Chromium(VI) oxide-tert-butyl hydroperoxide interactions:: evidence for a tert-butylperoxychromium complex and its role in the catalytic oxidation of alcohols

Based upon UV-visible and NMR spectroscopic studies in benzotrifluoride (BTF, alpha,alpha,alpha -trifluorotoluene) it has been shown that the purple colored species obtained from the reaction of t-BuOOH with CrO3 is a tert-butylperoxychromium complex, preferably formulated as (t-BuOO)(HO) CrO2. This complex, which is more stable in aromatic solvents than in haloalkanes, decomposes with time into tert-butylchromate. This transformation is greatly accelerated by the addition of benzyl alcohol. A catalytic cycle for the oxidation of alcohols is proposed.