Methodology Studies On Novel Organic Reactions Directed By Sulfur Atom

In recent years,the one-step generation of carbon-carbon bonds and other carbon-heteroatom bonds through the coordination of transition metals and directing group(DG)has broken through the limitations of the traditional synthetic methods,making the reaction easier,greener and more efficient,therefore this strategy has been widely used in the synthesis of important natural products,drug molecules and functional materials.At the same time,the DG-assistance strategy has attracted wide attention from chemists because of its good atomic economy,wide substrate adaptability and good reactivity.And how to use the strategy of directing group assistance to promote the activation of inert hydrocarbon bonds,carbon-carbon bonds and other carbon-heteroatom bonds,and enhance the regioselectivity of reactions,as well as make various many kinds of chemical transformations realized are always the hot topics in organic syntheses.Among the numerous known directing groups,the groups which,contain O and N are the most prevalent ones.However,there are relatively few studies on sulfur-containing groups,which mainly focus on thioethers and sulfoxides.Moreover,sulfur is widely found in organic molecules.How to synthesize useful sulfur-containing drug backbones or use common sulfur-containing groups to induce new reactions has yet to be studied.Therefore,it is of great significance to develop new sulfur-based organic syntheses methods.We have discovered and developed a new cheap,stable,sulfur-containing directing groups,and two new types of reactions are developed by this directing groups.In this dissertation,we will focus on the ortho-asymmetric two-fold C-H functionalization of thiourethane phenolate and the C-N activation of thiourea under palladium-catalyzed conditions with thiocarbonyl as the directing group.Dithiocarbamate phenolic esters,thioureas and thioamides are cheap starting materials.They are potential precursors for the syntheses of drug backbones owing to other simple preparations and stable chemical properties.The study of such reactions not only has academic significance,but also has great values in industrial production and pharmaceutical syntheses.