Oxidation-reduction reactions without hydrogen transfer

The Meerwein-Ponndorf-Verley reduction of aldehydes and ketones and its reverse, the Oppenauer oxidation of alcohols, are hydrogen-transfer reactions that can be performed under mild conditions and without the risk of reducing or oxidizing other functional groups [1]. The hydrogen donors are easily oxidizable secondary alcohols (e. g. i-PrOH) and the oxidants are simple ketones (e. g. cyclohexanone). Industrial applications of the MPVO reactions are found in the fragrance and pharmaceutical industries, for example. 

Most reactions that occur in living cells are some form of oxidation-reduction reactions. Oxidation-reduction reactions must occur together, since no substances can lose electrons without another substance gaining electrons. In biological systems, oxidation-reduction reactions involve not only transfer of electrons but also transfer of hydrogen that has both one proton (H+) and one electron. Oxidation of H2 gas will result in the release of H+ and one electron ... 

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