硅胶负载的亚胺环钯催化剂的制备、表征及催化性能

Preparation and Characterization of Silica-Supported Imine Palladacycle Complex and Its Catalytic Performance

利用SiO2表面硅羟基与有机硅烷作用制得氨基化SiO2,再与邻甲氧基苯甲醛反应,可得到键合在SiO2微粒表面的席夫碱配体,该配体与Li2PdCl4甲醇溶液反应得到SiO2负载的亚胺环钯催化剂.采用傅里叶变换红外光谱、X射线固体粉末衍射和X射线光电子能谱等手段对催化剂进行了表征,并用于催化碘代苯(PhI)与丙烯酰胺(AM)反应生成反式-肉桂酰胺的反应中,考察了溶剂、温度、原料比、缚酸剂及其用量、催化剂用量和反应时间对催化性能的影响,从而得到适宜的反应条件,并探讨了反应机理.

The silica-supported imine palladacycle complex was synthesized by the following procedure as,first,NH2-modified silica was obtained by grafting with organosilane;second,the as-obtained silica compound was treated with o-methoxybenzaldehyde to form SiO2-NH2-Schiff base;at last,the catalyst was attained after being reacted with Li2PdCl4-methanol solution.The as-prepared complex was characterized by Fourier transform infrared spectroscopy,X-ray powder diffraction,and X-ray photoelectron spectroscopy techniques.The catalytic activity test was carried out in Heck reaction of iodobenzene with acrylamide to the trans-cinnamamide.The effect of reaction parameters on the product yield was investigated,such as solvent,reaction temperature,molar ratio of iodobenzene to acrylamide,kinds and amount of base,amount of catalyst,and reaction time.The optimum reaction conditions were established and the possible reaction mechanism was discussed.