Highly Efficient Oxidative Coupling of Thiols and Oxidation of Sulfides in the Presence of MCM-41@Tryptophan-Cd and MCM-41@Tryptophan-Hg as Novel and Recoverable Nanocatalysts

Two heterogeneous catalysts, MCM-41@Tryptophan-Cd and MCM-41@Tryptophan-Hg, were synthesized by immobilization of Cd or Hg complexes on MCM-41 as novel, efficient, recoverable and stable nanocatalysts for Oxidation of sulfides to sulfoxides and oxidative coupling of thiols into their corresponding disulfides. These functionalized complexes were characterized by FT-IR spectroscopy, thermogravimetric analysis (TGA), powder X-ray diffraction (XRD) and N-2 adsorption-desorption isotherms. The designed catalysts successfully oxidized a variety of sulfides and thiols with short reaction times in high to excellent yields at room temperature and recovered for several times without significant loss of their catalytic activity. Synthesis of Cd and Hg tryptophan complexes immobilized on to surface of mesoporous MCM-41 under mild reaction conditions has been presented. After characterization of these catalysts, their catalytic activity has been investigated for the synthesis of sulfoxide and disulfides derivatives. [GRAPHICS] .