Studies On The Trifluoromethylthiolation Reactions Of AgSCF₃

It is well known that trifluoromethylthio groups?SCF₃?have many unique properties,such as high lipophilicity,strong electron-withdrawing effect and ideal biological activity.Introduced SCF₃ groups into an organic molecule,the parent compounds will undergo dramatic change in the acidity,dipole moment,lipophilicity,bioavailability and metabolic stability.As the hot topic in the field of organofluorine chemistry,compounds containing trifluoromethylthio functional groups has played an increasingly important role through trifluoromethylthiolation in the fields of medicine,pesticides and materials.Due to such some drawback in the traditional trifluoromethylthiolation processes as harsh reaction conditions,complex substrates,unstable trifluoromethylthiolation reagents,the stable and easy-to-operate silver?I?trifluoromethanethiolate?AgSCF₃?was selected in our thesis to develop some trifluoromethylthiolation reactions with milder conditions,wider range of substrates.The main contents of the dissertation are as follows:Firstly,the oxidative trifluoromethylthiolation reaction of alkenes with AgSCF₃ was investigated.Using inexpensive and readily available alkenes as substrates,the reaction can be carried out efficiently under mild conditions.The substrate scope studies shows that the reaction possesses such excellent substrate compatibility as aromatic alkenes,aliphatic alkenes and?,?-substituted unsaturated alkenes,with?-SCF₃-substituted ketone compounds in moderate to good yields.In addition,this synthetic methodology provides an attractive strategy for the construction of?-SCF₃-substituted ketones,in the field of organic synthesis,pharmaceutical and medicinal chemistry.Secondly,copper???catalyzed denitrative trifluoromethylthiolation of?-nitro-styrenes was developed.This reaction was carried out smoothly in DMSO at 60^°C in the presence of copper?II?trifluoroacetate,using K₂HPO₄ as an additive.The transformation tolerates well a wide range of substrates containing electron withdrawing and electron donating groups,with high stereoselectivity and moderate to good yields.The easy-to-operate reaction provides an alternative strategy for constructing the alkenyl-SCF₃ compounds using?-nitrostyrenes as substrates,with high substrate compatibility and excellent stereoselectivity.Finally,copper???promoted trifluoromethylation of aryl diazonium salts was studied.The important trifluoromethylthio aromatic compounds could be obtained in 55-92%yields through reaction of aryl diazonium fluoroborates with AgSCF₃ in the presence of equivalent copper iodide,using K₂CO₃ as base.With so many advantages as very mild reaction conditions?i.e.,reaction at room temperature and under air?and easy availability of aromatic amine starting materials,this transformation is a valuable complement to the previously established Sandmeyer trifluoromethylthiolation reactions.The aforementioned trifluoromethylthiolation reactions were carried out with different aromatic substrates,using stable and readily available AgSCF₃ as a trifluoromethylthiolation reagent.Various types of trifluoromethylthiolation products can be obtained through the synthesis methods developed in this thesis.As the hot research topics in recent years,these trifluoromethylthiolation reactions improve the shortcomings of traditional trifluoromethyl-ation reactions with great significance in industry and academia.