N-Methylmorpholine N-Oxide

Introduction

N-Methylmorpholine N-oxide [NMMO (2)] is a light yellow powder with a melting point of 180–184 °C.[1] It is commercially available in both the monohydrate (C₅H₁₁NO₂·H₂O) and anhydrous forms, and is stable under normal conditions.

Apart from being a powerful environmentally friendly solvent for dissolving cellulose,[2] [3] NMMO (2) acts as a strong oxidizing agent and is generally utilized as a stoichiometric oxidant together with TPAP and OsO₄ for hydroxy group oxidation[4] and dihydroxylation of olefins.[5] [6]

The oxidative dehydrogenation of amines utilizing gold as the catalyst is also carried out in the presence of NMMO (2), where it acts as a base to afford imines in good yield.[7]

Moreover, NMMO (2) can react as a nucleophile, as is displayed during the reductive work-up of ozonolysis intermediates to afford aldehyde products.[8] [9] One of the advantages of using NMMO versus oxidants like hydrogen peroxide is found in the fact that the byproduct after oxidation [NMM (1)] is very low in basicity.

• References

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