Oxidations using supported reagents

Klabunde, K.J., Fazlul Hoq, M., Mousah, R, Matsuhashi, H. (1987) Metal Oxides and their physico-chemical properties in Catalysis and Synthesis. In Preparative Chemistry using supported reagents. Academic Press, London. 

Scheme 2.4 Polymer-supported oxidations using a hypervalent iodine reagent. 

In contrast there are many examples for reduction processes on polymeric supports, because it is an especially useful transformation for aromatic nitro compounds in solid-phase chemistry. The reaction can be divided into two general classes polymer-bound substrates and polymer-bound oxidant- and reductant-reagents. 

The Anelli oxidation of alcohols to aldehydes and ketones has been accomplished using polymer-supported nitroxyl radical catalysts. The practicality of removing polymer-supported reagents by filtration to simplify product purification is highlighted by these examples. Bolm and coworkers11 demonstrated that a silica-supported nitroxyl catalyst is easily filtrated after use from the reaction solution, recovered and recycled, and the residual inorganic salts present in the reaction mixture are separated from the organic product by aqueous extraction (Table II, entry 7). 

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