Oppenauer oxidation

Schematic of the Oppenauer oxidation. Reagents: primary or secondary alcohol, Aluminum isopropoxide catalyst, excess ketone (acetone). Product: ketone. Comments: This reaction is reversible. The excess ketone reagent pushes the equilibrium forward to product.

The Oppenauer oxidation is an organic reaction used to convert a primary or secondary alcohol to a ketone using another excess ketone reagent (such as acetone) and an aluminium triisopropoxide catalyst. The mechanism begins with the alcohol replacing one of the isopropoxide groups on the aluminum to generate isopropanol. Acetone then coordinates to the aluminum complex and a rearrangement reaction occurs which includes a hydride transfer from the alcohol to acetone. This process, which oxidizes the alcohol and reduces the acetone, results in the formation of the final ketone product and regeneration of the aluminum triisopropoxide catalyst.[1]

Mechanism

Mechanism of the Oppenauer oxidation. Oppenauer Oxidation Catalytic Cycle.

References:

1.
Oppenauer, R. V. Recl. Trav. Chim. Pays-Bas 1937, 56, 137–144.