Synthesis And Application Of Novel Magnetic Nanoparticles Graphene In Organic Synthesis

In recent decades, the role of the catalyst in the reaction of chemistry has attracted extensive attention. However, due to many limitations, such as, high prices, the poor yield,difficulties in separating-recycling and many other factors, most of the catalysts cannot be widely applied. Especially in the field of pharmaceutics, it is important to discover an easy recycling catalyst of high utilization. Graphene is deeply favored by chemists since its unique two-dimensional structure of one-single-atom thickness, high conductivity and charge mobility, large specific surface area, excellent mechanical properties, thermal properties and electrical properties and so on. Meantime, under the action of strong oxidizing agents the carbon-carbon double bond of graphene is oxidized into some oxygen-containing groups,such as epoxy, carbonyl, hydroxyl, carboxyl and other reactive groups.Due to the difficulties of graphene in recycling, we synthesize a new type of magnetic nano catalyst Fe3O4@GO@Mo. The ?-hydroxy hydroperoxides was obtained in high-yield with epoxide as its primitive material in the presence of Fe3O4@GO@Mo at room temperature. The catalyst is separated with an external magnet, and used in subsequent runs without observation of significant decrease in activity even after six runs. After that we apply the novel magnetic nano-material Fe3O4@GO@Mo catalyst into the synthesis of spiroindole derivatives. This magnetic catalyst exhibited excellent catalytic activity for the synthesis of a wide variety of spiroindole derivative via one-pot three-component reactions of isatin derivatives, malononitrile and 4-?phenylamino?furan-2?3H?-one derivative in eutectic solvent?choline chloride: urea = 1:2? with heating of microwave. The reaction proceeded in deep eutectic solvent and provided the corresponding products in good to excellent yields. Deep eutectic solvents have been used to the development of a green protocol for the simple and efficient preparation of various spiroindole compounds owing to its ease of recovery and reuse.We also synthesized a novel magnetic nano-material Fe₃O₄@GO@SO₃H, and used as a magnetically recoverable catalyst for an efficient one-pot synthesis of pyrazolo[3,4-b]pyridinederivatives. A series of pyrazolo[3,4-b]pyridine derivatives were obtained in high-yield with5-amino-1-phenyl-3-?pyridin-3-yl?-1H-pyrazole, aromatic aldehyde, 3-oxo-3-?pyridin-3-yl?propionitrile as its primitive material in eutectic solvent?choline chloride:glycerol = 1:3? in the presence of Fe₃O₄@GO@SO₃H at 80?. Magnetic nanomaterials have high catalytic activity for synthesis of pyrazolo[3,4-b]pyridine compounds with many advantages such as simple, easy separation and recyclability.