Hypervalent Iodine-mediated Oxidative Coupling Of Aromatic Compounds In Heterocyclic Synthesis

This thesis describes our research work on the applications of phenyliodine diacetate (PIDA) and phenyliodine bis(trifluoroacetate) (PIFA)-mediate oxidative coupling reactions to the synthesis of N-heterocycles. It consists of three chapters.In the first chapter, the synthetic applications of PIDA and P1FA mediated oxidative coupling reactions of phenolic compounds and electron-rich aromatic compounds are briefly reviewed. The second and the third chapters deal with our own studies which are summarized as follows. (1) The PIFA-promoted intramolecualr coupling of 4-hydroxyphenyl-N-phenylbenzamides. We found that 4-hydroxyphenyl-N-phenylbenzamides reacted with PIFA to afford the 3,3-spirooxindoles in good to exllecent yields. The reactions could also take place in a catalytic way by employing 0.1 equiv. of iodobenzene as catalyst and m-CPBA or urea-H2O2 as the stochiometric oxidant. The reaction provides an efficient and mild method for the synthesis of 3,3-spirooxindoles. (2) The reactions of N-(4-ethoxyphenyl)benzamides and N-(4-acetamidophenyl)benzamindes with PIFA. In the presence of Lewis acid BF3·Et2O or TMSOTf,N-(4-ethoxyphenyl)benzamides and N-(4-acetamidopheny])benzamindes could be oxidized by PIFA, giving rise to the intramolecular C-O oxidative coupling products benzoxazoles.