氯化钴/希夫碱新型催化体系催化双羰化反应的研究

研究了氯化钴与不同的希夫碱所组成的新型催化体系对氯苄及其衍生物的双羰化反应的催化性能。结果表明,氯化钴/吡啶-2-羧酸钾的催化活性最佳,而且不同取代基团的氯苄衍生物的双羰化反应活性不一样。同时,首次引入了溶剂极性经验参数ET(30)来更为全面地衡量溶剂的性质对该反应活性的影响关系。在氯化钴/吡啶-2-羧酸钾的催化下,以1,4-二氧六环和水为混合溶剂时,氯苄进行催化双羰化反应生成苯丙酮酸,产率达70.1%,选择性达98.3%。并就该催化体系在实验条件下生成的催化活性物种进行了初步探讨。对氯化钴/吡啶-2-羧酸钾催化体系的回收套用的研究结果表明,一批次催化剂可以有效地催化双羰化反应4次,催化剂总转换数可达171。

Studies on the Double Carbonylation Catalyzed by a New Catalytic System: CoCl2/Schiff-Bases

The double carbonylation of benzyl chloride and its derivatives catalyzed by CoCl_2 and some schiff-bases as ligands,such as potassium pyridine-2-carboxylate(KPyca),1,10-phenanthroline,2,2′-bipyridine,etc.,were studied.It was found that CoCl_2/KPyca had the highest catalytic activity among these species.The conversion of benzyl chloride was 71.3%,and the yield of phenylpyruvic acid was 70.1% with a selectivity of 98.3% when the reaction was carried out for 10h at 353K and 2.8MPa of CO in the Ca(OH)_2 /dioxane/H_2O system,with CoCl_2 0.035mol/l,KPyca 0.13mol/l.Effects of solvents on the double carbonylation are discussed in detail.It has been shown that parameter E_T(30)measures the polar of solvents more overall in comparison with constant ε.The recovery of the CoCl_2/KPyca catalytic system in the double carbonylation was also investigated.The catalysts could be recycled for four times and the total TON of CoCl_2 reached 171.