Oxidative C-C bond cleavage of primary alcohols and vicinal diols catalyzed by H₅PV₂Mo₁₀O₄₀ by an electron transfer and oxygen transfer reaction mechanism

Primary alcohols such as 1-butanol were oxidized by the H₅PV₂Mo₁₀O₄₀ polyoxometalate in an atypical manner. Instead of C-H bond activation leading to the formation of butanal and butanoic acid, C-C bond cleavage took place leading to the formation of propanal and formaldehyde as initial products. The latter reacted with the excess 1-butanol present to yield butylformate and butylpropanate in additional oxidative transformations. Kinetic studies including measurement of kinetic isotope effects, labeling studies with ¹⁸O labeled H₅PV₂Mo₁₀O₄₀, and observation of a prerate determining step intermediate by ¹³C NMR leads to the formulation of a reaction mechanism based on electron transfer from the substrate to the polyoxometalate and oxygen transfer from the reduced polyoxometalate to the organic substrate. It was also shown that vicinal diols such as 1,2-ethanediol apparently react by a similar reaction mechanism.