Polymerization- and Solvent-Triggered Cooperativity Between Copper(II) Ions in the Catalysis of the Hydrolysis of Amino Esters by Pyridine-Based Ligands
作者:Paolo Scrimin、Paolo Tecilla、Umberto Tonellato
DOI:10.1002/(sici)1099-0690(199806)1998:6<1143::aid-ejoc1143>3.0.co;2-u
日期:1998.6
Polymeric (2) and oligomeric (4, 5) materials made of repeating units of 2,6-diaminomethylpyridine and 4,4′-diphenylmethane have been synthesized with the number of monomeric units (n) ranging from 2 to 29. In 1:1 DMSO/water solutions, these materials are fully soluble and strongly bind CuII ions. The complexes catalyze to different extents the hydrolysis of the p-nitrophenyl esters of α-, β-, and γ-amino acids
聚合物(2)和低聚(4,5)由2,6- diaminomethylpyridine和4,4'-二苯基甲烷的重复单元的原料已经合成了与单体单元的数量(Ñ范围从2到29。1): 1 DMSO /水溶液,这些材料是完全可溶的,并与Cu II离子牢固结合。该络合物在不同程度上催化α-,β-和γ-氨基酸的对硝基苯基酯的水解。仅利用Cu II的聚合物络合物2(Ñ ≥10)是更有效的催化剂比游离的Cu II离子在β-氨基酯的裂解中。当与单体配体(N,N'-苄基)-的Cu II配合物进行比较时,这种增强的反应性在β-丙氨酸对硝基苯酯(β-AlaPNP)的情况下几乎达到两个数量级。仅当达到一定聚合度时(6 < n <10),才在1:1(v / v)DMSO / H 2 O中观察到2,6-氨基甲基吡啶(3)。在1:1(v / v)CH 3 CH 2 OH / H 2 O中,聚合物2(n = 10)的配合物的动力学益处在9:1(v