Cyclodesulfurization and decarboxylation mediated with superoxide and sulfonyl peroxy radicals

Abstract

Superoxide ($O_2^$), one-electron reduction product of molecular oxygen, has recently become the subject of considerable chemical and biological interest and investigation. It is known to have the potential of acting as a redox agent, as a nucleophile or as a base. We have found that thioureas and thioamides react readily with superoxide at room temperature to give the corresponding cyclic compounds by one step reaction in excellent yields under mild conditions. The cyclodesulfurization of thioureas and thioamides appear to involve the formation of key intermediate of peroxysulfur dioxide and/or trioxide. 2-Nitrobenzene sulfonyl peroxy radical intermediate which is generated in situ inv the activation from 2-nitrobenzenesulfonyl chloride turn out to be a strong electrophilic oxidant for the oxidation of olefins, arenes, sulfides, and sulfoxides. It has been found that arylacetic acids react with 2-nitrobenzene sulfonyl peroxy radical intermediate at -20℃ under mild conditions to yield corresponding aldehydes, ketones and alcohols in good yield by a decarboxylation elimination and benzylic ethers react with 2-nitrobenzene sulfonyl peroxy radical intermediate to yield esters compounds in good yields.