Catalytic Hypervalent Iodine Catalysts
Mechanism + Description
The activation of the aryl iodide catalyst by oxidation 'in situ' by Oxone, followed by the expected oxidation mechanism for IBX/ Dess-Martin reagents. The reduced catalyst is re-oxidized to the high valent active form and the aldehyde product is further oxidized via the hydrate to the acid.
A number of examples have been published using terminal oxidants (mainly Oxone) to generate hypervalent iodine compounds in situ. These react very much as stoichiometric IBX/Dess Martin reagents. The oxidation of the primary alcohol to the aldehyde occurs, followed by a second oxidation of the aldehyde hydrate. These catalytic methods avoid having to use isolated unstable/explosive hypervalent iodine reagents.
Thottumkara, A. P.; Bowsher, M. S.; Vinod, T. K. In Situ Generation of o-Iodoxybenzoic Acid (IBX) and the Catalytic Use of It in Oxidation Reactions in the Presence of Oxone as a Co-Oxidant. Org. Lett. 2005, 7 (14), 2933-2936.
Relevant Scale-Up Examples with Scheme
No scale-up examples identified.