Study On Novel Multicomponent Reactions Of Metal-Catalyzed/Photocatalyzed Thiocarbolation Of Alkenes

Nitrogen,sulfur,and fluorine are widely found in drugs,pesticides,food additives,and a variety of materials.Thiazolane rings containing nitrogen and sulfur atoms are also present in a variety of drug molecules.Compounds containing trifluoromethyl（CF₃）or perfluorinated substituted alkane group(C_nF_2n+1)have great application potential in the pharmaceutical field.In addition,although the construction of C-S bond has been reported,the green,low energy,environmentally friendly,safe and easily available preparation method preparation methods are still in urgent need of research.New thiazolidins and isothioureas containing trifluoromethyl（CF₃）and perfluorinated substituted alkane(C_nF_2n+1I)compounds were obtained by intramolecular and intermolecular olefin difunctionalization multicomponent methods catalyzed by metal and phosphorus/photocatalysis,respectively.It has potential application value in the field of new drug discovery and pharmaceutical process.This work is composed of two parts.The first part is the multicomponent reaction of intramolecular and intermolecular thio-trifluoro methylation of alkenescatalyzed by copper.The second part is a novel multicomponent photocatalytic intra-molecular and intermolecular thiopolyfluoroalkylation of alkenes without metal involvement.In the first part of the work,we used cheap CuCl as the catalyst,cesium carbonate as the base,and dichloroethane as the solvent at 75℃.Thiourea formed in situ from N-allyl-N-arylamine and benzoyl isothiocyanate as sulfur source and Togni Ⅱ as trifluoromethyl source undergo olefin difunctionalization reaction not only the thiazolane ring with C-S bond is constructed,but also the trifluoromethyl functional group is introduced.In addition,using CuCl as catalyst,DMAP as base and acetonitrile as solvent at room temperature,we also realized the intermolecular three-component reaction of substituted thiourea,alkene and Togni Ⅱ at room temperature,efficiently and selectively providing isothioureas containing trifluoromethyl substitution.The reaction conditions of the two multicomponent reactions are mild,economical,and have a wide range of substrates and good functional group tolerance.In addition,the reaction mechanism was also studied.In the second part of the work,we improved the reaction conditions from metal catalysis to photocatalysis,which is more clean,environmental protection and low energy.Through screening photocatalysts,solvents and bases,mild optimized conditions were obtained.Inexpensive PPh₃ and P（p-Cl（C₆H₄））₃were used as photocatalysts,respectively.We not only realized olefin difunctionalization from in situ formed thioureas as a sulfur source derived from N-allyl-N-arylamine with benzoyl isothiocyanate and iodinated perfluoroalkyl as carbon source to providing perfluoroalkyl substituted thiazolane rings.Especailly,this method can also be used to synthesize 6-9 rings.We also achieved a new intermolecular olefin difunctionalization reaction of thioureas,alkenes and iodine-substituted perfluoroalkyl(C_nF_2n+1I),providing isothiourea compounds containing perfluoroalkyl substitution with high efficiency and selectivity.In additon,the feasibility of the novel multicomponent reaction of phenol,alkenes and perfluoroalkyl was preliminarily explored.