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Highly regioselective metal-free oxidative cyclization of sulfonamides onto tethered, unactivated alkenes by using hypervalent iodine and Bronsted acids is described. The acid counterion is incorporated into the cyclized products in order to provide an overall aminotrifluoroacetoxylation of the alkene.

Application of [H.sub.2][O.sub.2] in conjunction with SO[Cl.sub.2] as a highly reactive reagent for the direct oxidative conversion of thiol derivatives to the corresponding sulfonyl chlorides with high purity through oxidative chlorination is described. The same reaction with amines could be used to generate corresponding sulfonamides in excellent yields within short duration of reaction times.

New tosyl derivatives of 2-iodylaniline and 2-iodylphenol are prepared by the dimethyldioxirane oxidation of the corresponding 2-iodophenyltosylamides or 2-iodophenyl tosylate and isolated as stable, microcrystalline products. Single-crystal X-ray diffraction analysis of N-(2-iodylphenyl)-N,4-dimethylbenzenesulfonamide has shown pseudocyclic structure formed by intramolecular IaO interactions between the hypervalent iodine center and the sulfonyl oxygens in the tosyl group.

The reaction of [[Cp*Rh[Cl.sub.2]].sub.2] (Cp* = [[eta].sup.5]-[C.sub.5][(C[H.sub.3]).sub.5]] with 2 equiv of p-toluenesulfonamide in the presence of KOH has formed the sulfonylimido-bridged dirhodium(III) complex. The redox interconversion between the sulfonylimido-bridged dirhodium(III) and sulfonylamido-bridged dirhodium(II) complex is applied to catalytic aerobic oxidation of [H.sub.2] and an alcohol by using sulfonylimido-bridged dirhodium(III) as a well-defined dinuclear catalyst.

The structural consequences of receptor-like protein tyrosine phosphatase [alpha] (RPTP[alpha]) membrane distal domains (D2) oxidation are investigated. The results have shown that formation of the reversible cyclic sulfonamide is a general feature of the tyrosine specific PTPs and have demonstrated the susceptibility of the D2 catalytic Cys to oxidation, with potential implications for redox-depndent regulation of RPTP[alpha] conformational changes and catalytic activity.