Iodine-Promoted Electrophilic Cyclization For The Synthesis Of Halogenated Compounds

This thesis mainly studies the synthesis of halogenated compounds via electrophilic iodocyclization,which involves the flowing four chapters.Chapter ?:We first introduced the importance and practicability of halogenated compounds.We mainly introduced the halogenated natural products with biological or physiological activity;the effect of halogenated compounds in life;the application of halogenated compounds in medicine,agriculture and industry;and the application in organic synthesis.We continued to discribe the methods for the synthesis of halogenated compounds,especially the methods via electrophilic iodocyclization.Subsequently,we showed the categories of electrophilic iodocyclization,which was combined with alkene,alkyne,propargyl alcohols and allene,respectively.Chapter ?:We developed the synthesis of iodocarbazoles through electrophilic iodocyclization of homopropargylic alcohols with indole groups,along with migration and aromatization.We explore the optimum reaction conditions and functional group tolerance,and the iodocarbazole products can be further elaborated by palladium-catalyzed coupling processes.Chapter ?:The macrocyclic polyethers were obtained from homopropargylic alcohol substrates through electrophile-triggered tandem iodocyclization/intermolecular acetalation sequence.The homopropargylic alcohol substrates of primary alcohol and secondary alcohol proceeded smoothly.The tertiary alcohol substrate failed to afford the corresponding product due to the huge steric hindrance,the substrate was decomposition.Chapter ?:We described the synthesis of 6,9-dihydropyrido[1,2-a]indoles in detail through electrophilic iodocyclization of propargyl alcohols with indole groups.In addition to electrophilic reagent of I₂,we also used IBr and ICl as electrophilic reagents to obtain the dihalogenated products and verified the reaction mechanism.