RhCl3-catalyzed disulfide exchange reaction using water solvent in homogeneous and heterogeneous systems

RhCl3 catalyzed the alkylthio exchange reaction of hydrophilic disulfides in water under homogeneous conditions, and equilibrium was attained in several hours. The reaction was applied to the exchange of unprotected glutathione disulfide. The reaction of dimethyl disulfide and hydrophilic disulfides under heterogeneous conditions also proceeded effectively. The mechanism turned out to be dependent on the water solubility of the substrates: The reaction of bis(3-hydroxypropyl) disulfide took place in the dimethyl disulfide phase, whereas the reaction of bis(6-aminohexyl) disulfide dihydrochloride proceeded in the water phase.