Using The Reductive Strategy C-S Coupling Reaction And Alkyne Difunctionalization Reaction

Organic thioether compounds exist widely in natur e products,medical supplies,herbicides,ligands and functional material s,and were one of the important organic structural units.For a long time,synthesis workers were committed to promoting the development and progress of vulcanization,and the preparation of organic sulfide compounds has been extensively studied and repor ted.Among them,transition-metal-catalyzed C-S coupling reactions were the most common strategy to synthesize organic thioether compounds.However,most thiols and their oxidized derivatives have strong pungent odor,and some compounds are highly toxic,which limits their practical application and development to a certain extent.In recent years,the transition-metal-catalyzed C-S coupling reaction method to synthesize organic thioether compounds has been developed rapidly,especially using the reductive strategy the C-S coupling reaction,which makes the research focus in the field of organic synthesis shift to this field.Quinolinones are the basic framework of many nature products and drug active molecules.As a class of important drug molecules with antibiotic,anticancer,antiviral and other biological activities,quinolin-2-ketone compounds have been widely used in biomedicine industry,pesticide preparation and synthesis of important organic intermediates,and become the research focus of organic chemists.In recent years,the transition-metal-catalyzed reductive difunctionalization reactions of unsaturated hydrocarbons have made great progress in the field of organic synthesis,especially the transition-metal-catalyzed reductive difunctionalization reactions of alkynes.It is one of the greenest and most efficient methods for constructing multi-substituted complex molecular structures.In this paper,we introduce nickel-catalyzed C-S reductive coupling reaction of alkyl halides with aryl-thiotrimethylsilane and thiotrifluoromethyl arylsulfonate,and rhodium-catalyzed reductive difunctionalization of o-acetylenyl arylα-bromo-carbonyl compounds with formic acid/trimethylacetic anhydride,toward alkyl aryl thioether compounds and quinoline-2-ketone compounds.This paper was divided into a literature review and three research contents to elaborate:Recent advances in C-S coupling reactions and alkyne difunctionalization reactions using reductive strategies were reviewed.Among them,the C-S coupling reactions of alkyl halides with aryl thiotrimethylsilane and thiotrifluoromethyl arylsulfonate using reductive strategies were reviewed.The C-S coupling reactions using transition-metal-catalyzed,photocatalytic and electrocatalytic reducti ve strategies were respectively reviewed.Reductive difunctionalization reactions of o-acetylenyl arylα-bromo-carbonyl compounds with formic acid/trimethylacetic anhydride were summarized and discussed.The reductive difunctionalization reactions of alkynes using transition-metal-catalyzed and light/nickel co-catalyzed were discussed.A nickel-catalyzed alkyl halides with aryl-thiotrimethylsilane for producing alkyl aryl thioether compounds via intermolecular C-S reductive cross-coupling reaction at room temperature and without base.This reaction is initiated by umpolung trans-formations of arylthiotrimethylsilanes followed by C-S reductive cross-coupling,nickel-catalyzed/manganese as the reductive agent in the catalytic system,alkyl halides react with arylthiotrimethylsilane,and can obtain alkyl arylthioether compounds with excellent separation yield.A cooperative nickel cataysis and N,N-dimethylformamide-mediated strategy for umpolung C-S reductive cross-coupling of S-（trifluoromethyl）arylsulfonothioates with alkyl bromine to assemble alkyl aryl sulfide.This reaction features excellent selectivity,wide functionality tolerance,broad substrate scope,and facile late-stage modification of biologically relevant molecules.Mechanistic studies recognize initial generation of an amidyl radical anion by thermoinduced reduction of DMF with Sn,followed by umpolung reduction and single electron transfer of the nucleophilic sulfonyl moiety to form a sulphydryl radical and engagement of the Ni⁰/Ni^I/Ni^III/Ni^Icatalytic cycle.A rhodium-catalyzed alkyne-tetheredα-bromo-N-arylacetamides with formic acid/trimethylaceticanhydrideforproducing cyclopenta[de]quinoline-2,5（1H,3H）-diones is described via using a radical carbonylation strategy.This method has good compatibility with the use of formic acid/trimethylacetic anhydride to provide carbon monoxide source,broad substrate scope and excellent functionality tolerance,and facile late-stage modification of biologically relevant molecules.