高活性氨基胍树脂负载Pd(0)配合物的催化性能研究

以氨基碳酸胍改性氯球为载体, 与氯化钯溶液反应并还原制备氨基胍树脂负载钯(0)催化剂. 对催化剂进行了FT-IR, XRD, BET, TG-DTA表征. 研究了该催化剂对各种取代卤代苯与丙烯酸、苯乙烯的Heck芳基化反应催化性能. 实验结果表明, 该催化剂对活性(吸电子基)溴代苯和碘苯具有良好的催化活性, 对含活性吸电子基的溴代苯(4-溴苯甲醛和4-溴硝基苯)于140 ℃时能在22 min内完成Heck 芳基化反应; 催化剂具有较好的重复使用性能, 在90 ℃下催化碘苯与丙烯酸的反应循环21次时仍能保持良好的催化活性. 反应机理研究表明: 催化反应的活性组分是可溶性钯物种; 可溶性钯是由卤代苯与催化剂表面上的钯氧化加成所致.

Catalytic Characteristics of Highly Active Amino-guanidine-resin Supported Pd(0) Complex

Amino-guanidine-resin supported Pd(0) was prepared by the reaction of amino-guanidine modified chloromethyl polystyrene resin with PdCl₂, followed by reduction. The catalyst was characterized by FT-IR, XRD, BET, TG-DTA. The catalytic performance for the Heck reactions of various substituted aryl halides with acrylic acid or styrene was studied. Experiments indicated that the catalyst had excellent activity and recycling. Aryl bromides with electron-withdrawing were converted completely within very short time (140 ℃, 22 min). At 90 ℃ in the reaction of iodo-benzene with acrylic acid, the catalyst could kept high activity at 21th run. The study on mechanism disclosed that the reaction was homogeneous catalytic reaction, and the palladium leaching was caused by the interaction of iodo-benzene with the metal Pd(0) on supported.