Synthesis Of β-Ketoamine Ligands And Their Catalytic Apokucatuib In Suzuki Coupling Reaction

Palladium-catalyzed C-C bond reactions such as Suzuki cross-coupling reaction have attracted significant interest during the past decades. The advantages of the Suzuki reaction include the tolerance of functional group on the substrates and mild reaction conditions. As an intriguingly flexible reaction, it offers considerable potential in the synthesis of natural products, herbicides, pharmaceuticals, and conducting polymers.Today phosphine ligands have been gradually replaced by nitrogen ligands in Suzuki cross-coupling reaction.β-ketoamine ligands have been researched extensively. A series ofβ-ketoamine ligands with different steric and electronic substituents on backbone and aniline moieties have been synthesized. The ligands which were complexed to PdCl₂ in situ were successfully employed in Suzuki cross-coupling reactions in aerobic conditions. The effects of solvent and bases on Suzuki cross-coupling reaction were investigated. It revealed that the L4 with steric and electron-donating structure was most efficient, enabling a wide variety of aryl bromides to be coupled with phenylboronic acid in high yield. EtOH/H₂O and K₂CO₃ was found to be the most suitable in all coupling reactions.1. synthesis of ligandsA seriesβ-ketoamine ligands with different electronic property, rigidity and steric hindrance were prepared by condensation ofβ-enamino keton and aniline. These ligands were complexed to PdCl₂ in situ and successfully employed in Suzuki cross-coupling reactions. The structures of ligands were characterized through 1^H-NMR and (13)^C-NMR.2. Suzuki coupling of aryl fluoride catalyzed byβ-ketoamine ligands/PdCl₂ systems In the third chapter we are mainly talking about Suzuki coupling reaction of aryl fluorid catalyzed byβ-ketoamine ligands/PdCl₂ systems. Theβ-ketoamine ligands were applied to the Suzuki coupling reaction of beomobenzene which could be carried out in EtOH/H₂O solvent. Low loading of palladium catalyst (1 mol%)were necessary for the coupling reaction. The coupling reaction could be smartly carried out at 60 oC in EtOH/H₂O solvent. The catalytic system has been found to tolerate several of functional groups. The structures of products were characterized through 1^H-NMR and (13)^C-NMR. Yield of product determined by GC.1. A series ofβ-ketoamine ligands have been prepared and were successfully employed for the Suzuki cross-coupling reaction under aerobic condition.2. The experimental data showed that backbones as well as the anilines with bulky and electron-donating groups on ligands are facilitate for the Suzuki cross-coupling reaction.3. Reaction conditions of the Suzuki cross-coupling concluding solvent, bases and temperature were optimized.4. It revealed that the L4 with steric and electron-donating structure was most efficient, enabling a wide variety of aryl bromides to be coupled with phenylboronic acid in high yield.