The Reactivity Of Acetyl Group And Its Updated Development On The Synthesis Of (Carbon) Heterocyclic Structures

As a kind of important precursors and basic structural elements in organic synthetic chemistry,acetyl compounds has its unique reactivity,which is widely used in the synthesis of complex structures such as natural products and functional molecules.So far,various synthetic methods of(carbon)heterocyclic structures have been developed based on the reactivity of acetyl group,in which acetophenones,aliphatic methyl ketones,acetamides,1,2-dicarbonyl compounds and 1,3-dicarbonyl compounds are usually involved via C-H activation,sp C-H functionalization,oxidative coupling,condensation,cleavage,etc.In this dissertation,we focus on acetophenones in I2-DMSO system,which could be converted in situ to high active intermediates:a-iodo acetophenone and phenylglyoxal.With the capture of these intermediates by different molecular fragments,we realized the synthesis of primary a-ketoamides and imidazo[1,2-a]pyridine derivatives,and investigated the reaction mechanism of these novel synthetic methods respectively.The main contents are as follows:In chapter 1,the applications of acetyl compounds in the synthesis of(carbon)heterocyclic structures were firstly summarized and then our research subject was proposed based on the research status and our previous work.In chapter 2,considering that a-ketoamides are embedded in a wide range of biologically active natural products and pharmaceuticals,and primary a-ketoamides are valuable precursors in organic synthetic chemistry,we developed a highly efficient molecular iodine catalyzed oxidative amidation of aryl methyl ketones with the use of formamidine hydrochloride as an amino surrogate for the construction of free(N-H)a-ketoamides through a self-sequenced iodination/Kornblum oxidation/amidation/oxidation/decarbonylation cascade reaction.In chapter 3,considering the important application values of imidazo[1,2-a]pyridine derivatives in the field of pharmaceutical chemistry and optoelectronics,many developments have been made on the synthesis of imidazo[1,2-a]pyridines.Meanwhile,the C-H bond functionalization of imidazo[1,2-a]pyridines have been extensively studied due to the electron-rich nature of the C-3.Nevertheless,the construction of imidazo[1,2-a]pyridine ring along with methylthiolation at C-3 and iodination at C-6 in one-pot remains challenging.We developed an NH2CN-promoted four-component coupling reaction for the synthesis of 6-iodo-3-(methylthio)-2-arylimidazo[1,2-a]pyridines from aryl methyl ketones and 2-aminopyridines in the presence of I2 and DM SO via convergent integration of three self-sorting domino sequences,and revealed a novel self-organization reaction network mode.