N-Heterocyclic Carbene(NHC)-Catalyzed Cascade Construction Of Pyran、Pyridine、Pyrazol Skeleton

This thesis is composed of five sections:In the first section, the applications of N-Heterocyclic Carbenes(NHCs)-catalyzed cascade reactions in field of organocatalyst are reviewed.Section two introduced a simple and flexible procedure for the synthesis of a series of spirocyclic oxindole-dihydropyranones.In the third section, a new efficient approach to the tetrahydroimidazo[1,2-a]pyridines was successfully developed through oxidative NHC-catalyzed cascade C-N bond and C-C bond formation process. The reaction features mild conditions, moderate to high yields and operational simplicity.In section four, a series of pyrazolinones were directly obtained from phenylhydrazine hydrochloride and enals catalyzed by using oxidative NHC catalysis.The fifth part described the reaction of α,β-unsaturated esters and 1,3-dinucleophiles under NHC catalysis which afforded a series of dihydropyranones.All of the products were characterized by IR, 1H NMR and HRMS. The structures of some products were confirmed by 13 C NMR.