Oppenauer Oxidation

AbstractThe Lewis acid, primarily aluminum tri‐isopropanoxide (i.e., Al(O‐i‐Pr)3), catalyzed oxidation of secondary alcohols into ketones using another ketone or an aldehyde as the oxidant, which in turn is reduced to the corresponding alcohol is generally referred to as the Oppenauer oxidation. The interchange between alcohols and ketones in the presence of an aluminum catalyst is referred to as the MPVO reaction. It has been observed that this reaction shows high selectivity and is a very common method for the preparation of ketones. The study finds that the Oppenauer oxidation has problems in the oxidation of primary alcohols and α‐amino alcohols. The application of aluminumt‐butoxide as catalyst is sufficient for the oxidation of an α‐amino at high temperature. In addition, cyclohexanone can also be used as oxidant because of its high oxidation potential. The Oppenauer oxidation has been extensively modified by the application of different transition metal compounds as catalysts. Among these modifications, the Cp*Ir(III) complex andN‐heterocyclic carbene ligand produce the good results. This reaction is very useful in the preparation of ketones.