Study On Ruthenium Catalyzed Regioselective C-H Functionalization Of Arenes

In this paper,ruthenium catalyzed regioselective C-H functionalization of arenes has been systematically studied,mainly including the following five chapters:Chapter Ⅰ:Ruthenium catalyst has excellent catalytic performance,various valence states,and is cheaper than other precious metals.The conversion of various valence states promotes the diversity of ruthenium catalyzed reactions.In recent years,the regioselective C-H activation of arenes catalyzed by ruthenium has made rapid progress.In this chapter,according to different catalytic reaction models,we systematically introduced the research progress of ortho-,meta-and para-C-H functionalization of arenes catalyzed by ruthenium,and summarized the reaction mechanism.Chapter Ⅱ:In this chapter,the ortho-selective amination of arenes was realized by using a tensional ternary ring electrophilic aminating reagent（di-tert-butyldiaziridinone）based on pyridine directed ruthenium catalyzed ortho-C_Ar-H activation.This strategy has good functional group compatibility with various phenyl substituted nitrogen-containing heterocycles,and further derivations could obtain highly functionalized aniline derivatives.Mechanistic studies showed that the reaction process may involve an octahedral ruthenium species,and the control experiment also showed that carbon monoxide as a ligand played a crucial role in the reaction process.Chapter Ⅲ:This chapter has realized a position selective C-H phosphorylation of arenes and heteroarenes under visible light.The reaction conditions conformed to the concept of green chemistry.The cost-effective Ru Cl₃ was used as the catalyst,and water was used as the solvent at room temperature without adding additional ligands.In addition,the reaction was a cross-dehydrogenation-coupling（CDC）reaction with high atomic economy.In terms of mechanism research,we also revealed that Ru Cl₃ was a single-electron-transfer（SET）visible light catalyst for the first time through ultraviolet absorption spectrum and on/off light control experiments.Chapter Ⅳ:Radical cyclization has been emerged as one of the most important reaction types,which is widely used in natural product synthesis,pharmaceutical chemistry and materials science.In this chapter,we combined radical cyclization with ruthenium catalyzed meta-selective C-H functionalization of arenes to achieve the synthesis of a series of arylpyrrolidone derivatives.Firstly,primary,secondary and tertiary alkyl radical intermediates were formed by intramolecular radical addition cyclization.Subsequently,the radical addition reactions of primary,secondary and tertiary alkyl radical intermediates with aryl cyclic ruthenium complexes exhibited the highly meta-site selectivity.Density functional theory（DFT）calculation indicated that the reaction belongs toσ-activation mechanism,and provided a theoretical basis for its highly meta selective C-H functionalization and intramolecular cyclization catalytic cycle.Chapter Ⅴ:C-aryl glycosides have important applications in biochemistry and pharmaceutical chemistry.This chapter described a ruthenium-catalyzed highly stereo-and site-selective C-H glycosylation of arenes,and synthesized a series of ortho and meta substituted C-aryl pyranosides and furanosides.This strategy has a wide scope of substrate,which could be compatible with a variety of N-heterocyclic directing groups.The control experiment and density functional theory（DFT）calculation showed that the ortho-C_Ar-H glycosylation might undergo the process of oxidative addition/reduction elimination,while aryl meta-C_Ar-H glycosylation was mediated byσ-activation strategy.In addition,the mechanism study also showed that the highly diastereoselectivity of meta-C_Ar-H glycosylation was due to steric hindrance.