Synthesis Of Organic Sulfur Compounds Catalyzed By Cu（OTf）₂ And Their Fungicidal Activity

Carbon is one of the most basic elements making up the living body.The carbon-heteroatom bond formed by carbon and other heteroatoms is a very important chemical bond in organic compounds.Sulfur element plays an important role in the biological process of organic life,so the formation of carbon-sulfur（C-S）bond has become one of the most valuable chemical bonds in organic synthesis.For a long time,the innovative synthesis method of C-S bond has always been a hot frontier in organic chemistry research,due to the important applications of organic sulfides in medicine,pesticides,materials and biological metabolism.The fluorine is the element with the highest electronegativity in the periodic table.When it is connected with the carbon,it forms a highly polarized C-F bond.Because the fat solubility and bioaffinity of the parent molecule are greatly improved after the insertion of fluorine atoms,methods of forming C-F bonds have been widely reported.The introduction of trifluoromethyl group（-CF₃）is the most feasible way to introduce fluorine atoms into molecules.One of the schemes,the special properties of organic fluorides make them have important applications in biomedicine and other fields.Based on the important role of S and F elements in the creation of new pesticides,this thesis focuses on the synthesis of thioether and thioketal featuring-CF₃ groups catalyzed by Cu（OTf）₂,and the exploration of the bactericidal effect.（1）Conjugated addition reaction of thiols to enones catalyzed by Cu（OTf）₂Sulfide is a kind of important organic sulfide containing C-S bond.It is not only widely present in drugs and biologically active molecules,but also has important significance for the research and development of perfumes and fragrances.In this work,through the catalysis of copper trifluoromethanesulfonate,the conjugate addition of thiols toα,β-unsaturated ketenes was realized,and a series ofγ-carbonyl sulfides were obtained.We have investigated the metal catalysts,solvents,and additives and found that the yield is the highest at room temperature for 14 hours in a dichloromethane solution containing 10 mol%copper trifluoromethanesulfonate.Subsequently,the scope of the substrate was investigated,and finally 42 sulfide products were obtained with a yield of 37-99%.All products were characterized by ¹HNMR,¹³CNMR and HRMS,and the characterization data and corresponding spectra were given.For the synthetic compounds,we selected 5 representative products for biological testing,and found that four of them are against Botrytis cinerea,Alternaria solani,Fusarium graminearum,and Rhizoctonia solani produced certain inhibitions effect.（2）Disulfide condensation reaction ofβ-CF₃-enone catalyzed by Cu（OTf）₂In the previous reports of dithioacetals（dithioketals）,most of the isolated carbonyl groups were used as the research object,regardless of the situation with functionalgroups（especially in metal catalysis）,so that in theapplication of actual carbonyl group protectionketone or aldehyde bearing other functional groups may not be compatible with the metal conditions required for condensation,leading to the failure of reported methods.In order to make up for this gap,this work usesβ-CF₃-enone as starting material,exploring the disulfide condensation reaction of the enone containing CF₃ at theβposition to carbonyl group.The raw materialβ-CF₃-enone is synthesized by trifluoroacetophenone and Wittig reagent in dichloromethane solvent in one step.Through the screening of metals,additives and solvents,the best conditions were found to be 10 mol%copper trifluoromethanesulfonate,5 equivalents of trimethylchlorosilane and chloroform/ether solvent.After examining the substrate compatibility,we obtained 24 new compounds with yields of 35-99%,and provided characterization data and graph.This method can be scaled up to the gram level and can also be deprotected with good yield,which proves the practicability of this method.We also selected 5 representatives of the 24 new compounds for biological testing,and found that four of them are against Botrytis cinerea,Alternaria solani,Fusarium graminearum,and Rhizoctonia solani also produced certain inhibitions effect.