Peroxyselenic acids

Mechanistically, oxidizes SeO into peroxyselenous acid, which promotes the oxidation of the pyrrolidine nitrogen (Scheme 2.31). The resulting intermediate is then hydrolyzed to form the desired ketone along with a diazene byproduct. 

A PS-peroxyselenic acid (29) was prepared by treatment of PS-mercury(II) chloride (30) with selenium dioxide followed by 30% hydrogen peroxide (Scheme 10). In a triphase system, consi ting of (29) (1.5 mol %), 1.5-1.8 equivalents of 30% aqueous hydrogen peroxide and dichloromethane, alkenes were oxidized to 1,2-diols, and ketones to esters or lactones. The polymeric seleninic acid (31) could be reoxidized to the PS-peroxyseleninic acid (29) and recycled with no apparent loss of activity. 

It is noteworthy that selenium, arsenic and boron compounds are also effective catalysts for the selective epoxidation of alkenes by H2O2 (equations 34-36). It is generally thought that peroxyselenic and peroxyarsonic acids act as reactive intermediates in a way similar to that of peroxycarboxylic acids. Metaboric acid, HBO2, acts as both an epoxidation catalyst and a dehydrating agent. The resulting orthoboric acid can be dehydrated back to metaboric acid. ... 

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