高分子固载化Lewis酸催化剂——聚苯乙烯-三氯化铝/四氯化钛复合物

<正> 均相催化剂的固载化是目前催化剂研究方向之一。Skct等首次将BF_5和AlCl_3分别与苯乙烯反应制成高分子催化剂,对酯化、缩醛、缩酮等有机反应具有良好的催化作用。我们曾将四氯化钛与聚苯乙烯反应制成一种稳定复合物,有良好的催化效能。为了改进其重复使用性能,本文将等摩尔的AlCl_3,和TiCl_4的Lewis酸同时与聚苯乙烯交

POLYMER-SUPPORTED LEWIS ACID CATALYST——POLYSTYRENE-AlCl_3/TiCl_4 DIBASIC METAL CHLORIDE COMPLEX

Polystyrene-DVB (4%) copolymer beads is combined with anhydrous A1Cl₃ and TiCl₄ (1:1) in CS₂ to form a stable complex containing 11.4% of chlorine, in which the ratio of the both metals is about 2:1 (Al/Ti = 2/1). It correspond to (6.42×10^-4 mol A1Cl₃ +3.21×10^-4 mol TiCU)/l g. complex beads. The complex can be used to catalyze a lot of organic synthesis reactions in high yield, such as esterifications, acetalizations, ketal formations, etherifications and the Friedel-Crafts alkylations. The activity of PS-Al/Ti is greater than PS-AlCl₃ and PS-TiCl₄^[4-7].It is important to note,that the complex PS-Al/Ti as a catalyst can be used repeate-dly with high yields.