Studies On Selenium-Catalyzed Synthesis Of Asymmetric Sulfides And Selenides

The asymmetric sulfides are important material of fine chemistry and intermediates of organic synthesis, widely used in medicines, pesticides, dyes and food additives industry.The paper studied a new synthetic method of the asymmetric sulfides, by the selenium-catalyzed CO/H₂O system with disulfides and halogenated hydrocarbons as raw materials. In the study, several disulfides as the raw materials also could be synthesized by the selenium-catalyzed CO/H₂O system with halogenated hydrocarbons or aldehydes. Therefore, after disulfides were synthesized in the selenium-catalyzed CO/H₂O system, the corresponding halogenateds could be directly added to synthesis the asymmetric sulfides. This method achieved multi-step reactions completed in one reactor, without separating of intermediate products. In this way, it not only simplifies the reaction equipment and operation procedures, but also cuts down cost by reducing process time and the volume of solvent used.In addition, the （4-methoxybenzyl）（benzyl）selenide was synthesized by the selenium-catalyzed CO/H₂O system with 1,2-bis（4-methoxybenzyl）diselenide and benzyl chloride as raw materials. And, based on the experimental data, the mechanism of this reaction was proposed.The effects of temperature, solvent and base conditions were investigated. The results indicated the optimizing conditions in which asymmetric sulfides can be synthesized in high yield. Products were characterized by 1H NMR or GC-MS. Some shallow understanding of mechanism which asymmetric sulfide compounds were synthesized are postulated.