Study OnVO（acac）₂/H₂O₂ Catalytic Oxidation Of Series Of Diaryl Thioether Compounds

Sulfide（R₁-S-R₂） compounds have a variety of categories, its various oxidation products sulfoxide and sulfone thioether compounds have broad spectrum of biological activities and widespread application value. So synthesis and selective oxidation of thioether compounds have been one of the research hotspots for scholars and researchers. This thesis designed and synthesized different kinds of diaryl thioether compounds, and then explored their selective oxidation behavior under different conditions. The main content is divided into the following three parts:（1）Using five different synthetic methods to prepare thioether compounds, starting from three different aryl thiols and a dozen different halogenated aromatic hydrocarbons as reactants. Under different synthetic conditions, the yield is between 50 to 100%.Further study on the different synthesis methods of the reaction conditions from material sources, yield, time, solvent, temperature and other aspects, we choose a relatively optimal, simple and easy way, which is of economy and environmental protection, and could be used in most of the thioether compounds synthesis: 5mol%CuI as a catalyst, PEG400 as a reaction medium, arylthiols and iodobenzene according to the ratio of 1:1 as starting materials, at 120 oC in 12 hours.（2） According to the optimal synthesis method, 32 kinds of diaryl thioether compounds are synthesized and characterized. Moreover, the crystallization conditions of thioether compounds from amorphous state into crystal state are studied. Single crystal X-ray diffraction analysis was performed to determine the molecular structure of 11 different diaryl sulfide compounds. In addition, the synthetic yield and purity of the compounds were detected by gas chromatography.（3） By improving the conditions of VO（acac）2/H2O2 catalytic system, this thesis broadens the scope of the system for catalytic oxidation of sulfide compounds. By adjusting the catalyst oxidant ratio and reaction time, sulfide could be selectively transformed to the corresponding sulfoxide or sulfone compounds.11 molecular structures of oxidation products were characterized and determined by single-crystal X-ray diffraction analysis.