Preparation Of Cu/C₃N₄ Catalyst And Its Utilization In Organic Reactions

In recent years,carbon nitride materials are widely used in electrochemical,materials and other fields because of their easy preparation and superior performance.However,its utilization for organic catalysis has not been closely concentrated ever.In this thesis,Cu/C₃N₄ was prepared by a simple method and catalyzed the homo-&cross-coupling reaction of terminal alkynes.Moreover,thethree-componentcouplingreactionofaldehydes,alkynesand tetrahydroisoquinoline?THIQ?was also achieved by utilizing Cu/C₃N₄.Firstly,the starting materials of melamine and Cu?AcO?₂ were mixed through ball-milling method,the Cu/C₃N₄ was prepared by roasting the mixture of melamine and Cu?OAc?₂.Then,the composite was characterized by TEM,XRD and XPS.The analysis showed that Cu/C₃N₄ maintains the flexible sheet-like morphology of C₃N₄ with no obvious nanoparticles and Cu?0?makes up a majority of the Cu present.The main research work of this thesis are as the following:?1?The Glaser-Hay coupling reaction catalyzed by Cu/C₃N₄ under mild conditionThe Cu/C₃N₄ utilized as a highly efficient and environmental friendly catalyst for homo-&cross-coupling of terminal alkynes with oxygen as oxidant at room temperature.In the presence of isopropanol as additive or solvent,excellent functional group tolerance and good yields were achieved.Furthermore,the Cu/C₃N₄ catalyst showed high catalytic activity and could be reused for over 10 times without significant loss of activity,which providing a novel green strategy to the synthesis of a variety of 1,3-diynes.?2?Cu/C₃N₄ catalysed the A3 reaction of aldehydes,alkynes and THIQBased on the above result,the A3 reaction of aldehydes,alkynes and THIQ was also achieved by using Cu/C₃N₄ as catalyst and 4?MS as water removal agent in toluene.This catalytic system showed excellent functional group tolerance and good catalytic performance.Furthermore,the Cu/C₃N₄ catalyst exhibited good recyclability and could be simply recovered and reused for 5times without significant loss in catalytic activities.In summary,with Cu/C₃N₄ composite as catalyst,a facile,efficient,and environmental friendly synthetic strategy for Glaser-Hay coupling reaction was developed.Moreover,the A3coupling reaction could also be achieved by utilizing Cu/C₃N₄.The composite catalyst was tolerant of a wide variety of functional groups and good to excellent yields were achieved in most examples.