水杨醛席夫碱Pd配合物的合成、表征及催化Suzuki偶联反应研究

Synthesis and characterization of salicylaldehyde Schiff base-Pd complex and study on its application in catalyzing Suzuki coupling reaction

以水杨醛和2-氯-4-氟苯胺合成的席夫碱为配体,采用溶剂热法生成新型Pd(Ⅱ)配合物(Ⅰ)。利用傅里叶红外、热重、PXRD、X-射线单晶衍射等测试手段对其进行结构表征与性质研究。结果表明,配合物(Ⅰ)在P2_(1)/c空间群中属于单斜晶系,通过亚胺N和酚O供体原子以双齿方式与1个钯(Ⅱ)中心配合。以制备的Pd(Ⅱ)配合物为催化剂,考察其催化溴苯与苯硼酸Suzuki偶联反应的反应条件,当催化剂摩尔分数为2%、K_(2)CO_(3)为助催化剂、EtOH为溶剂、反应温度为80℃、反应时间为6 h时催化产率高达99.6%。考察不同反应底物的催化反应效果,结果表明,含吸电子基团的卤代芳烃表现出更好的催化性能,且溴苯与苯硼酸反应的催化效果最佳。

A novel Pd(Ⅱ)complex is synthesized via solvothermal method by using palladium salt and Schiff base ligand obtained from salicylaldehyde and 2-chloro-4-fluoroaniline.It is characterized by means of FT-IR,TG,PXRD,SCD,etc.SCD analysis shows that the complex belongs to the monoclinic crystal system in the P2_(1)/c space group,and is coordinated to a Pd(Ⅱ)center in a bidentate manner via imine N and phenol O donor atoms.The prepared Pd(Ⅱ)complex is used as a catalyst for Suzuki coupling reaction between bromobenzene and phenylboronic acid,and the reaction conditions are optimized.Results show that the best yield reaches 99.6%when the usage amount of catalyst is 2mmol%,EtOH is used as solvent,K_(2)CO_(3) as co-catalyst,and the reaction has performed at 80℃for 6 h.Catalytic reaction effects of different reaction substrates are investigated.It is shown from results that the halogenated aromatic hydrocarbons containing electron-withdrawing groups show better catalytic performance,and deliver the best catalytic effect in the reaction between bromobenzene and phenylboronic acid.