Study On The Synthesis Of α-Formyl Pyrroles From Pyrroles And Pyrrole[3,2-c] Quinolinone Derivatives

The thesis consists of the following two aspects: 1. the synthesis of α-formylpyrroles from 2,3-dihydro-1H-pyrroles; 2. the synthesis of pyrrolo[3,2-c]quinolinone derivatives.1. The synthesis of α-formylpyrroles.α-Formylpyrroles are one of the most important five-membered heterocyclic compounds possessing important bioactivities and important intermediates of synthesis of poly-substituted pyrrole derivatives. Development of new practical and green methods to synthesize α-formylpyrroles is still a challenging task. In this work, we disclose a new tandem dehydrogenation/C-2 formylation reaction of 1,4,5-substituted 2,3-dihydro-1H-pyrroles that is effectively catalyzed by copper(I) iodide(CuI) in the presence of trifluoroacetic acid(TFA)and dimethyl sulfoxide(DMSO) to directly generate structural diverse α-formylpyrroles in one pot in moderate to good yields. During this reaction DMSO acts as both the carbonyl carbon source and solvent. It was found that all the substrates with electron-withdrawing groups on pyrrole ring underwent smoothly. Despite having some limitations, this tandem reaction provides a facile new protocol for the preparation of structurally sophisticated pyrrole compounds.2. The synthesis of pyrrolo[3,2-c]quinoline derivatives.Pyrrolo[3,2-c]quinoline derivatives possess interesting biological activities, such as anticancer, antibacterial activity, etc. Pyrrolo[3,2-c]quinoline derivatives can be prepared in several methods. In this thesis, we developed a directed C-H functionalization and intramolecular amide arylation for the efficient construction of substituted pyrrolo[3,2-c]quinolinones from 1,2,3-trisubstituted pyrroles in DMSO by using O2 as oxidant in the presence of catalytic CuI. It was also found that a-formyl pyrrolo[3,2-c]quinolinones could be finally obtained in the yield of 21%-35% if the reaction time was prolonged. The preliminary experiments suggested a feasible method to synthesize a-formylpyrrolo[3,2-c]quinolinones from 1,2,3-trisubstituted pyrroles in one pot which provides the means for further modifying pyrrolo[3,2-c]quinolinones.