Cobalt-Catalysis For The Construction And Transformation Of Sulfone Compounds

Synthetic chemistry has provided the material basis for the rapid development of modern society.In addition,sulfones are of great importance and widely exist in pesticides,pharmaceuticals,and functional materials.Thus,their synthesis has long been of interest to chemists.It is crucial to select cheap raw materials for developing robust and efficient methods to construct sulfones compounds value-added molecules.Among these,olefins play an essential role in organic synthesis methodology,in which bulk olefins can transform to value-added compounds.Recently,the revival of radical chemistry offers a new the synthesis of sulfones from alkenes.This thesis firstly outlines the traditional methods for synthesizing sulfones and the recent photocatalytic synthesis of sulfones,followed by the generation of sulfonyl radicals from p-toluenesulfonyl chloride under different initiation methods.In the research part,the allylic C-H sulfonylation of aryl olefins was achieved by using sulfonyl radicals as intermediates via merging radical addition to alkene and cobaltoxime promoted hydrogen atom transfer(HAT).Moreover,the combination of radical-mediated functional group migration and cobalt-catalyzed HAT enables alkene difunctionalization with sulfonyl chloride functionalization,thus providing a novel concept for the construction of sulfone compounds.The main findings of the thesis are as follows:1.Sulfonyl radicals are produced by Co(I)species induced by sulfonyl chloride,which adds to olefins.At the same time,the sulfones are constructed by cobaltoxime promoted hydrogen atom transfer process.The sulfonyl chloride is used as a substrate for the reaction with the olefins.The reaction conditions are mild,the substrates are widely adopted,and the target products are obtained in excellent yields even at the gram level.2.The selective conversion of olefins was achieved under mild conditions using a photo/cobalt dual-catalytic system,which was accomplished the difunctionalization of olefins while constructing new C-C double bonds at the remote site.The reaction with olefins using sulfonyl chloride as a radical precursor gives sulfones in moderate yields under mild reaction that are well compatible with heteroaromatic rings.