用元素分析、红外光谱、紫外光谱、荧光光谱和核磁等分析手段对合成出的1.0G树枝状大分子-水杨醛席夫碱钯配合物(PAMAMSAPd)进行了表征。用其作为催化剂,研究了碘代苯与丙烯酸在有机溶剂中的偶联反应。对于碘代苯与丙烯酸的偶联反应,最佳反应条件为:惰性气氛,10mmol PhI,nPhI∶nAA∶nEt3N=1∶1.5∶2.5,3.0×10^-3g PAMAMSAPd, 4mL DMF和100°C的反应温度。在该条件下,产物肉桂酸的产率可达96.5%。该树枝状大分子配合物是一种无磷、高效和稳定的Heck反应催化剂。且该催化剂经简单的过滤、溶剂洗涤进行回收,重复使用3次,产率仍能达到90.2%。
Dendritic poly(amidoamine)(PAMAM)-salicylidene salen palladium complex of the first generation (PAMAMSAPd) was synthesized and characterized by elemental analysis,FT-IR,UV-vis,Fluorescence spectra and NMR. It was evaluated as catalyst precursor in the Heck cross-coupling of iodobenzene (or its derivatives) and conjugate alkenes. For the cross-coupling reaction of iodobenzene with acrylic acid,the optimal condition was established as follows: 10mmol PhI,nPhI: nAA: nEt3N=1∶1.5∶2.5,3.0×10^-3g PAMAMSAPd,4mL DMF and 100℃ reaction temperature in the inert ambience. Under the above reaction condition,the yield of cinnamate can reach 96.5% at 90min reaction time. This dendimer complex was a phosphine-free,highly efficient and stable dendrimer catalyst for Heck reaction. In addition,this dendrimer catalyst could be used at least for four times without significant loss of yield.