Organosulfur, Sulfoxide And Sulfone Compounds Are Constructed Based On The Functionalization Of Alkenes And Alkynes

Sulfur-containing compounds have attracted a great synthetic pursuit of chemists in both academic and industrial communities due to their extensive applications in organic synthesis,the pharmaceutical industry,and materials science.Nevertheless,most of these reactions might suffer from certain limitations,such as the need for prefunctionalized thiolating reagents,limited substrate scope,harsh reaction conditions,low atom economy,poor-regioselectivity,or toxic metal catalysts.Therefore,it remains a challenging but attractive task to develop more direct,economic,efficient,and environmentally benign methods to construct sulfur-containing compounds.In this paper,some unsaturated hydrocarbon functionalization reactions have been successfully developed for the construction of a series of organic sulfur-containing compounds,such as?-acetylaminosulfides,sulfoxides,3-sulfonyl and 3-sulfenyl azaspiro[4,5]trienones,which are frequently found in many natural products,and pharmacologically active compounds and materials.Thesis mainly includes the following four parts:?1?Metal-free synthetic method for the construction of?-acetamido sulfides.Molecular iodine-mediated direct difunctionalization of alkenes with nitriles and thiols toward?-acetamido sulfide derivatives has been developed under metal-free conditions.The present protocol provides the facile and highly efficient approach to various?-acetamido sulfides in a scaled-up manner with good to excellent yields simply using inexpensive molecular iodine as a catalyst,DMSO as a mild oxidant,readily available thiols as thiolating reagents.?2?Visible-light-induced method for the selective synthesis of sulfoxides.A highly selective synthesis of sulfoxides from alkenes and thiols was established by visible-light photoredox catalysis at room temperature.A series of biologically important sulfoxides could be conveniently and efficiently prepared in moderate to good yields using simple and readily available materials.The present method is of great value from both green chemistry and organic synthesis perspectives because of its desirable features including operation simplicity,high atom efficiency,ecoenergy source,green solvent,metal-free catalysis and ambient conditions.The present method opens a new door toward the facile and practical construction of sulfoxides.?3?Silver-catalyzed method for the construction of 3-thioazaspiro[4,5]trienones.A new and convenient silver-catalyzed direct oxidative spirocyclization of alkynes with thiophenols leading to 3-thioazaspiro[4,5]trienones is described.Preliminary mechanistic studies indicated that this reaction might involve a radical process and the carbonyl oxygen atom of 3-thioazaspiro[4,5]trienones originated from the water.This methodology provides a simple and practical approach to various 3-thioazaspiro[4,5]-trienones in moderate to good yields with high atom efficiency and excellent functional group tolerance.?4?Visible-light-induced method for the construction of 3-sulfonyl and 3-sulfenyl azaspiro[4,5]trienones.A mild and convenient visible-light-induced method has been developed for the construction of 3-sulfonyl and 3-sulfenyl azaspiro[4,5]trienones through metal-free difunctionalization of alkynes with sulfinic acids or thiols at room temperature.The present protocol,which simply utilizes visible light as the safe and eco-friendly energy source,and inexpensive and non-toxic organic dyes?Eosin Y and Na₂-Eosin Y?as photocatalysts,providing various sulfur-containing azaspiro[4,5]trienones in moderate to good yields.With advantages such as simple operation,mild conditions,eco-friendly energy source and oxidant,as well as inexpensive and non-toxic photocatalysts,this new synthetic method is expected to find wide applications in synthetic and medicinal chemistry.