Study On Synthesis Of New Type Sulfoxonium Ylides

Sulfur ylides are a kind of zwitterionic compounds.Carbanions are stabilized by connected sulfide ions.Sulfur ylides can provide nucleophilic centers that are widely needed in organic synthesis.The negatively charged carbon atoms can interact with different electrophiles to synthesize compounds of different structures.During the reaction,positively charged heteroatoms can be removed as leaving groups,which provides an important method for organic synthesis as an indispensable part of modern chemical industry.Sulfoxonium ylides have been widely employed in organic synthesis for more than half a century,especially in the synthesis of materials and pharmaceutical active skeletons.They can be applied in X-H bond insertion reactions,constructing heterocycles through cyclization and taking part in many reactions as a kind of"superstar"one carbon or two carbon synthons.Due to the advantages of high stability,safe operation,easy storage and easy availability,etc,sulfoxonium ylides can not only be sevred as excellent surrogates for diazo compounds in metal carbene reaction,but also provide a new route for the synthesis of bioactive heterocyclic frameworks.Therefore,it has become one hot topic to explore new reactions of sulfoxonium ylides with various reagents.This thesis mainly study copper-catalyzed reactions of sulfoxonium ylides and a protocol for the synthesis of a novel kind of sulfoxonium ylides has been developed.The content of this thesis includes:1.Using ?-carbonyl sulfoxonium ylides as raw material,one molecule of carbene copper was formed,which attacked another molecule of ?-carbonyl sulfoxonium ylides to form?,?,?-tricarbonyl sulfoxonium ylides through homocoupling with the release of H₂O in the presence of dioxygen.2.Through exploring the reaction activity of this reaction under different copper catalysis,silver additives,solvents and different atmospheres,the optimal reaction conditions were set up as following:0.2 mmol of 1a,Cu(OAc)₂(10 mmol%)as catalyst,and CF₃COOAg(10 mmol%)as additive,at 90? under oxygen atmosphere for 12 hours.This method was featured with wide substrate scope,high yields and low price,etc.The reaction mechanism has been explored based on some control reactions.A possible mechanism was proposed.The use of silver additive played an important role in promoting the reaction yield.Moreover,some applications of the product have also been investigated.