Studies On Syntheses Of Ru-Arene Complexes/Bridged Alkenes

Ru complexes are widely used in catalytic reactions,drug discovery,and material science.Therefore,exploring a highly efficient and convenient method for preparing ruthenium aryl compounds is currently a hot topic in the field of metal organic chemistry.Meta-C–H activation is also a promising field because of its high reaction efficiency and atomic economy,and absolutely ruthenium-catalyzed meta-C–H activation is one of important parts.The first chapter summarizes the research on synthesis and applications of ruthenium complexes.The first part mainly introduces the preparation,bioactive applications of ruthenium complexes.The second part displays the coupling reactions of some Ru complexes,and various pre-prepared ruthenium complexes catalyzed functionalization reaction,such as catalytic C–H activation,hydrogenation and oxidation reaction.The second chapter we mainly expound our method for preparation of Ru-arene complexes.For one part of desired compounds,through a Concerted Metalation-Deprotonation?CMD?pathway,aryl pyridines react with[RuCl₂?p-cymene?]₂ in MeOH at room temperature to give high yields of corresponding Ru-arene complexes.For other complexes,through an ion exchange strategy,pre-prepared[RuCl?2-phenylpyridine??p-cymene?]is used as the substrate to react with sodium salts or copper salts in MeOH/THF?1:1?solution,then a series of[RuX?2-phenylpyridine??p-cymene?]are obtained,displaying good catalytic activity in meta-bromination of 2-phenylpyridine.The third chapter mainly describes our research on Ru-catalyzed meta-C–H activation.Initially,we use NIS or NCS,and then ICl or IBr as halogen sources to conduct the meta-iodination or chlorination reaction of 2-phenyloyridine,but fail to get the meta-C–H activation products,only obtain ortho-substituted phenyl pyridine and biphenyl pyridine compounds.In our later studies,in the presence of Ru catalyst,we successfully get the meta-arylation product of 2-phenylpyridine by using aromatic diazonium salts as the arene source,but in a low yield of the product 171.We would continue to explore more suitable conditions to enhance the yield of desired product.In addition,bridged olefins are widely used in polymeric materials,catalytic reactions,drug materials,etc.Direct functionalization of olefins has become a hot area because of its atomic economy and convenience.In chapter 4,we mainly introduce the direct functionalization reaction of KO^tBu-catalyzed PMDTA lithiation and bridged cyclic olefins under mild conditions.In the presence of KO^tBu,ⁿBuLi firstly forms a lithium intermediate with the ligand PMDTA,and then the alkenyl hydrogen of the norbornene compound is unplugged at 0 ^oC for 2 h,followed by different electrophile reagents are added to finish the functionalization reactions of norbornene and its analogues.By using the traditional Pd-Li coupling reaction,we successfully achieve the direct arylation reactions of norbornenes in our superbase system.It is noteworthy that the reaction with brominated bowlene,a curved aromatic compound,also obtains a 20%yield of the corresponding arylation product.We also get an important norbornene derivative 289,which is widely used in metal-catalytic reactions,in an overall yield of 49%.