Oxidative cleavage of tosylhydrazones and sulfilimines

Abstract

Arylperoxyseleninic acids were generated from arylseleninic acids and hydrogen peroxide in situ and found to be a good oxidizing agent of tosylhydrazone derivatives. Tosylhydrazones were found to react with the mixture of aqueous hydrogen peroxide and catalytic amount of arylseleninic acid in THF to convert into the corresponding carbonyl compounds in excellent yields under mild conditions. The o-nitrobenzeneseleninic acid is more efficient catalyst then benzeneseleninic acid for these oxidation reactions. The reaction system appears to be safe and is simple to work up. Thus, it may be promising for the deprotection of tosylhydrazone derivatives to the corresponding ketones under mild conditions. While, various sulfilimine derivativs were found to react with dinitrogen tetroxide in dry acetonitrile or THF to give the corresponding sulfoxide derivatives, in excellent yields. Dinitrogen tetroxide has been known to be self-ionized to $NO^+$ and $NO^-_3$ ion at low temperature in polar aprotic solvent. Dinitrogen tetroxide is the powerful nitrosating reagent at low temperature in acetonitrile or THF. The reaction appears to proceed via nitrosation on the nitrogen atom of S=N bond.