Mukaiyama oxidation

Although the Mukaiyama oxidation is not in the top list of the most frequently used alcohol oxidants, the authors of this book have decided to pay full attention to this procedure because it succeeds in very sensitive organometallic compounds, where most other oxidants fail. The Mukaiyama oxidation operates via a somehow unique mechanism involving a hydride transfer from a metal alkoxide to a very good hydride acceptor, which resembles the Oppenauer oxidation. In variance with the Oppenauer oxidation, the Mukaiyama protocol involves much milder conditions and it does not promote as easily base-induced side reactions. 

The obtention of this very labile product, containing an allylstannane and an aldehyde in the same molecule, was tried unsuccessfully using many oxidizing conditions. Eventually, this product could be prepared following a Mukaiyama oxidation. The basic conditions were essential to avoid protiodestannylation. The product could not withstand chromatography... 

Functional Group and Protecting Group Sensitivity to Mukaiyama Oxidation... 

The slightly basic conditions of the Mukaiyama oxidation are particularly well-fitted for oxidations in compounds containing organometallic moieties. These include allylstannanes,75 TT-allylmolibdenum compounds,76 alkyne Co(CO)6 complexes77 and diene Fe(CO)3 complexes.78... 

Many base-sensitive functionalities, such as carbonates79 or epoxides,75b resist the mild basic conditions of the Mukaiyama oxidation. 

There is one example in which an ethoxyethyl (EE) protecting group is removed from a phenol during a Mukaiyama oxidation. According to the authors, this deprotection is promoted by a selective complexation of one oxygen with a magnesium atom.80... 

T. Mukaiyama, Oxidation-Reduction Condensation, Angew. Chem. Int. Ed. Engl. 1976, 15, 94-103. 

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