Studies On Palladium-Catalyzed Insertion Of N-tosylhydrazones And Indine-Induced Cyclization Reaction

The thesis aims at the studies on Palladium-catalyzed insertion of N-Tosylhydrazones and Iodine-Induced Cyclization Reaction. It mainly consists of the following three chapters:Chapterl.In part1, Palladium-catalyzed insertion of N-TosylhydrazonesIn recent years, Pd-catalyzed insertion of diazo compounds has emerged as a new type of cross-coupling reaction was widespread concern. In this section, Palladium-catalyzed coupling reactions of unstable diazo compounds were summarized in detail. In the cross-coupling reaction, Migratory insertion of palladium-carbene species is proposed as a key step in these transformations. we introduced the palladium-catalyzed cross-coupling reaction of N-Tosylhydrazones compounds and Palladium-Catalyzed Cascade Reactions. The mechanistic studies on N-Tosylhydrazones compounds in Palladium-catalyzed reaction and their application in organic synthesis were also surveyed.In Chapter2. Iodine-induced cyclization reactionIodocyclization has emerged as an extremely useful protocol in the preparation of a variety of five or six-membered carbocyclic and heterocyclic ring systems. Iodine-mediated synthesis of different heterocycles is classified into following categories based on the manipulation of functional groups.(1) Activation of carbon-carbon double bond;(2) Activation of carbon-carbon triple bond;(3) Activation of carbonyl and imine;(4) Activation of enamine, thioamide, and hydrazone;The mechanistic studies on iodine-induced cyclization reaction and their application synthesis are also surveyde.Chapter2. Palladium-catalyzed insertion of α,β-unsaturated N-tosylhydrazones tandem reactionPreviously, we showed that the migration of aryl groups to arylvinyldiazoacetate or α,β-unsaturated N-tosylhydrazones can generate η3-allylpalladium intermediates, which could be attacked by amines. Over the years, we have been committed to malonate as carbon nucleophiles in palladium-catalyzed conditions, through the design tandem reaction, synthesized a series of cyclic compounds. In connection with above-mentioned, Two efficient palladium-catalyzed cross-coupling-cyclization reactions for synthesis of dihydronaphthalene derivatives and indene derivatives have been developed. A three-component coupling of iodobenzene, N-tosylhydrazones and carbon nucleophiles through palladium carbene migratory insertion and the carbopalladation process was also reported.Chapter3:Iodine-induced tandem cyclization reaction synthesis of polysubstituted tetrahydroquinolinesWe have developed a versatile, convenient and environment-friendly approach to synthesis2,2-disubstituted-tetrahydroquinoline via iodine-induced tandem cyclization reaction from propargylic alcohols and amines. A variety of the propargylic alcohols and amines are applicable in this process. we realized that the reaction is different from the previously reported electrophilic cyclization reaction of a nucleophile which is applied, and then through a series of iodine-induced cyclization to complete the process.