The Study Of Imine Cycloaddition Reaction For Synthesis Of Nitrogen-containing Heterocyclic Compounds

The nitrogen atom of the imines contains a lone pair of electrons, and the carbon atom containing a partial positive charge, thus, the imine can undergo both electrophilic addition reaction and nucleophilic addition reaction. On the other hand, the aldimine can also be used as aza-diene and dienophiles in cycloaddition reaction. Therefore, imines have versatile reactivity and have been widely used as key intermediates in a number of domino reactions to construct heterocyclic systems. In this thesis we have studied several cycloaddition reactions of functionalized imines and synthesized of a series of novel nitrogen-containing heterocyclic compounds.1. We investigated the domino Povarov reaction of imine and β-enamino ester, and successfully established the imino Diels-Alder reaction with β-enamino ester as dienophile. This reaction provides a convenient and stereoselective procedure for the preparation of2-aryl-4-arylamino-1,2,3,4-tetrahydroquinoline-3-carboxylates. When isatin-3-imines were used in the reaction, the functionalized spiro[indoline-3,2’-quinolines] were also obtained in satisfactory yields. All products were characterized by IR, NMR, HRMS spectroscopy. The single crystal structures of three products in this part were measured by X-ray diffraction method, which help to determine the configaration of the synthetic compounds.2. The three-component reaction of simple and readily available starting materials of aromatic amines, dialkyl acetylenedicarboxylates and isatins was carried out at different reaction conditions. The reactions showed the fruitful molecular diversity of multicomponent reaction. First, the1,4-dipolar cycloaddition reaction of isatin-3-imines with two molecules of acetylendicarboxylates afforded spiro[indoline-3,2’-pyridyl]-3’,4’,5’,6’-tetracarboxylates in high yields. Under similar conditions, the three-component reaction of aromatic amines, isatins and dialkyl acetylenedicarboxylate or methyl propiolate resulted in the isomeric spiro[indole-3,4’-pyridin]-2’,3’,5’,6’-tetracarboxylates or spiro[indole-3,4-pyridine] derivatives. The spiro compounds obtained were fully characterized by IR, NMR, HRMS spectroscopy. The single crystal structures of four products were measured by X-ray diffraction method.3. We successfully investigated one-pot domino reaction of arylamine, ethyl gloxylate and acetylenedicarboxylate and provided a convenient procedure for the preparation of the functionalized2-pyrrolidinones in good yields. The reaction was carried out under the room temperature, with using ethanol as the solvent, and benzoic acid was added as the catalyst. The compounds of this reaction were all characterized by IR, NMR, HRMS spectroscopy. And the single crystal structures of three products were measured by X-ray diffraction method.