Pd(Ⅱ)/γ-Al_2O_3催化有机锡试剂和酰氯偶联反应的研究

Study on the Coupling Reation of Organotins and Acid Chlorides Catalyzed by Pd(Ⅱ)/γ-Al2O3

有机锡试剂制备容易,活性适中,在钯的催化下和酰氯偶联,可以合成带有活性官能团的羰基化合物,因而引起了人们的重视。但是偶联反应通常使用的催化剂是PhCH_2(PPh_3)_2PdCl、Pd(PPh_3)_4,其制备繁锁;Pd(PPh_3)_4在空气中不稳定,易氧化;偶联反应结束后,钯以金属晶体析出,不能重复使用。因而,实际应用受到了限制。

Pd(Ⅱ) catalyst supported on γ-Al2O3 was prepared. The catalyst has high catalytic activity and chemical selectivity in the couping reaction of organotins and acid chlorides. It can be separated easily from the reaction mixture after reaction and can be reused for several times. The catalyst has been investigated by XPS 、XRD and electron microscope. The experimental results show that the metallic Pd may be the active center for the coupling reaction. Pd was dispersed evenly on the surface ofγ-Al2O3 and did not agglomerate after use.