Studying On The Sulfur Functionalization Of Unsaturated Hydrocarbon Using Sodium Sulfinate As Radical Precursor

Organosulfur compounds are widely found in natural products,proteins,and drug molecules,which have important applications in synthetic chemistry and biochemistry.As a classic sulfurizing reagent,sodium sulfinate（RSO₂Na）is one of the basic materials for the synthesis of organic sulfur compounds.Sodium sulfinate featuring in odorless,insensitive to water,easy to operate and stable in organic reactions.It can be used as nucleophilic,electrophilic and radical reagents in various organic transformations.As both of sulfone and sulfur radical precursor,sodium sulfinate have been extensively studied to be used for the construction of various sulfur-containing compounds.Sulfinyl radicals widely exist in the atmospheric environment and living organisms,which play an important role in life activities.However,due to the low reactivity of the sulfinyl radical itself and self-coupling reaction,it has not been used in synthetic chemistry.This is an urgent problem to be solved in sulfinyl radical chemistry.Sodium sulfinate is a potential green and safe sulfinyl radical precursor.It is of great significance to develop organic synthesis reactions involving sulfinyl radicals based on sodium sulfinate.Our group has been devoted to the study of sodium sulfinate as the precursor of sulfone radicals,and developed various radical reactions with unsaturated hydrocarbons.In this thesis,a highly reactive species-sulfinyl sulfones are used as the precursor of sulfinyl radical and sulfone radical,which is instantly generated by sodium sulfinate.A series of sulfur functionalization reactions with unsaturated hydrocarbons are developed.The specific research contents of this paper are as follows:（1）Studies on the sulfinylation sulfonation of alkenes and enynes:Using sodium sulfinate as the sulfinyl/sulfonyl diradical precursor,we successfully realized the sulfinyl/sulfonyl bifunctionalization reaction of alkenes,and prepared various alkyl-sulfonyl-sulfinyl compounds in an efficient manner.This strategy enable the first application of the sulfinyl radical in the organic reaction.The formation of sulfinyl sulfones in situ from sodium sulfinate and acetyl chloride is the key to the realization of the reaction.We successfully isolated the highly reactive intermediate-sulfinyl sulfones,and characterized by X-ray single crystal diffraction,NMR,and HRMS.The physicochemical properties was also studied systematically.Finally,we extend this strategy to radical tandem reactions with enyne systems which synthesize a series of sulfone and sulfinyl containing carbocyclic and heterocyclic.（2）Studies on the sulfinylation sulfonation of alkynes and benzynes:Due to the strong electrophilic effect of acetyl chloride,sulfinylation sulfonylation reaction is incompatible with highly reactive groups such as hydroxyl,carboxyl,amino,amide.Therefore,we developed a mild nucleophilic species-TMSCl to activate sodium sulfinate,which generate of sulfinyl sulfones as sulfinyl/sulfonyl diradical precursors for sulfinylation sulfonylation with alkynes,which realized the synthesis of alkenylsulfonylated sulfinated products.Various active groups such as hydroxyl,carboxyl,amino and amide can be effectively compatible with this reation system.In addition,this novel alkenyl-sulfonyl-sulfinyl product can be used in various transformations.Importantly,we also achieved the sulfinylation sulfonation of benzyne with sulfinyl sulfones intermediate to access aryl-sulfonyl-sulfinyl compound.（3）gem-Disulfonylation of vinyl azide:Using the sulfinyl sulfones formed by sodium sulfite and acetyl chloride as the sulfone radical precursor,it can react with vinyl azide to efficiently access the gem-disulfonyl enamine derivatives.Moreover,ortho-aryl substituted vinyl azide can be successfully used to construct methylsulfonyl-substituted phenanthridine compounds via radical cyclization.