Oxygen atom addition

Most of the Moco enzymes catalyze oxygen atom addition or removal from their substrates. Molybdenum usually alternates between oxidation states VI and IV. The Mo(V) state forms as an intermediate as the active site is reconstituted by coupled proton—electron transfer processes (62). The working of the Moco enzymes depends on the 0x0 chemistry of Mo (VI), Mo(V), and Mo (TV). 

Molybdenum trioxide technique H,S Photolysis 1 Radiolysis Mercury photosensitization of n-butanef Oxygen atom addition ... 

The bispyridine-substituted carbyne complexes 182 react with several anionic bidentate donor ligands to afford the anionic / -ketenyl complexes 183 [Eq. (149)] (149,167). The bis(pyrrole carboxaldiminato) complexes were further transformed into alkoxyacetylene complexes by methylation at the ketenyl oxygen atom. Addition of trimethylphosphine to the anionic carborane-substituted carbyne complex 184 at — 30°C gives the ketenyl complex 185 [Eq. (150)] (135). The hydroxy and methoxyacetylene complexes were obtained by further addition of HBF4 and methyl triflate. 

Much of the work on oxygen atom additions to olefins has been done by Cvetanovic and co-workers, and he has written a well-known review of this and other atom addition reactions [2], which constitutes an excellent summary of the older literature. A more general review of oxygen atom reactions by Herron and Huie [7] is now available. 

So to summarise, oxidation can involve addition of oxygen atoms, removal of hydrogen atoms or removal of electrons reduction, conversely, can involve removal of oxygen atoms, addition of hydrogen atoms or addition of electrons. 

Lugo-Mas P, Dey A et al (2006) How does single oxygen atom addition affect the properties of An Fe-nitrile hydratase analogue the compensatory role of the unmodified thiolate. J Am Chem Soc 128 11211-11221... 

Note that the new Nu-C bond is made up entirely of the electron pair of the nucleophile. The transformation is reminiscent of an Sn2 reaction. In that process, a leaving group is displaced. Here, an electron pair is moved from a shared position between carbon and oxygen to one solely on the oxygen atom. Additions of strongly basic nucleophiles to carbonyl groups typically follow the nucleophilic addition-protonation pathway. 

---