Boyland-Sims oxidation

What is Boyland-Sims oxidation?

The Boyland-Sims Oxidation, also referred to as the Boyland-Sims peroxydisulfate oxidation, was initially discovered by Boyland and Sims in 1953. This particular oxidation reaction converts primary, secondary, and tertiary aromatic amines to o-sulfate esters, which are then further transformed into the corresponding alcohols. The Boyland-Sims Oxidation is a two-step process that first involves the oxidation of aromatic amines by alkaline persulfate, yielding predominantly the o-amino aryl sulfates. The second step involves the conversion of o-amino aryl sulfates into o-hydroxy aryl amines through acid-promoted hydrolysis.

Boyland-Sims oxidation - Boyland-Sims peroxydisulfate oxidation
Boyland-Sims oxidation

Mechanism of reaction

According to the proposed reaction mechanism, the reaction begins with an ipso attack by peroxydisulphate. This is followed by the cleavage of the peroxide bond, resulting in the formation of an ortho-sulphate ester, as depicted in the figure below:

Boyland-Sims oxidation mechanism

References

Boyland, E.; Manson, D.; Sims, P., “The preparation of o-aminophenyl sulphatesJ. Chem. Soc., 1953, 3623-3628
DOI: 10.1039/JR9530003623

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