Preparation of pseudocyclic I( <scp>iii</scp> ) reagents and their application in selective oxidations

Four <i>N</i>,<i>N</i>-disubstituted pseudocyclic-type iodine(III) reagents were conveniently prepared in excellent yields from <i>ortho</i>-iodobenzamides using <i>m</i>CPBA as the oxidant under mild conditions. This class of hypervalent iodine(III) oxidants exhibited remarkable selectivity in oxidizing sulfides solely to sulfoxides, without any detectable sulfone formation, even when used in excess or at elevated temperatures. Mechanistically, the nucleophilic attack of sulfide generates the sulfonium intermediate, which enables the oxidation of sulfides.