Enantioselective hydrolysis of long chain α-amino acid esters by chiral sulfur-containing macrocyclic metallomicelles
作者:Jingsong You、Xiaoqi Yu、Xingshu Li、Qianshun Yan、Rugang Xie
DOI:10.1016/s0957-4166(98)00098-6
日期:1998.4
A novel chiral lipophilic sulfur-containing macrocyclic ligand 5 with bis-pendant alcohols in the proximity of the coordination center has been synthesized. Its metal ion complexes have been investigated as catalysts for the enantioselective hydrolysis of long chain α-amino acid esters in aqueous comicellar solution with Brij35. Large rate accelerations (up to 220 times) and moderate enantioselectivities
合成了在配位中心附近具有双侧链醇的新型手性亲脂性含硫大环配体5。已经研究了其金属离子络合物作为催化剂在Brij35水溶液中对长链α-氨基酸酯进行对映选择性水解的方法。已经观察到使用大环5- Cu 2+的大速率加速(高达220倍)和中等对映选择性(高达4.85(k S / k R)),而无环3- Cu 2+表现出较低的反应性和立体选择性。取类似的配体4,缺少羟基会导致速率急剧下降,并且观察到对映选择性反转。在我们的胶束反应条件下,与Cu 2+结合的羟基的pKa值确定为pKa = 7.2。