Novel chiral N4S2- and N6S3-donor macrocyclic ligands: synthesis, protonation constants, metal-ion binding and asymmetric catalysis in the Henry reaction.
Novel chiral N4S2- and N6S3-donor macrocyclic ligands: synthesis, protonation constants, metal-ion binding and asymmetric catalysis in the Henry reaction.
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DOI：
10.1039/b305582e
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发表时间：
2003-07
影响因子：
3.2
通讯作者：
Jian Gao;A. Martell
中科院分区：
文献类型：
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作者：
Jian Gao;A. Martell
采用Schiff碱缩合法合成了含手性二氨基和噻吩基团的新型疏水手性大环配体L1-L3。用电位滴定法测定了L1和L2的质子化常数。金属离子结合实验表明，L1和L3对所测金属离子（Cu ~（2+）、Co ~（2+）、Ni ~（2+）、Zn ~（2+）、Cd ~（2+）、Pb ~（2+）、Ag ~（2+）、Li ~（2+）、Na ~（2+）、K ~（2+）和Ca ~（2+））具有明显的选择性识别作用。发现L1光谱检测Cu 2+和Ca 2+的存在，以用作多重读出传感器。在CH_2Cl_2-MeOH溶液中，Ca ~（2+）离子的检测限为9.8 × 10 ~（-5）M。三聚体手性配体L3在Zn（II）介导的对映选择性亨利反应中是一种有效的助剂。
New hydrophobic chiral macrocyclic ligands L1-L3 with chiral diamino and thiophene moieties have been synthesized by the Schiff base condensation approach. Protonation constants of L1 and L2 were determined by potentiometry titration. Metal-ion binding experiments exhibited that L1 and L3 are pronounced in selective recognition, Ag+, Cu2+ and Ca2+ ions among the surveyed metal ions (Cu2+, Co2+, Ni2+, Zn2+, Cd2+, Pb2+, Ag+, Li+, Na+, K+, and Ca2+). L1 was found to spectroscopically detect the presence of Cu2+ and Ca2+ to function as a multiple readout sensor. The detection limit for Ca2+ ions was found to be 9.8 x 10(-5) M in CH2Cl2-MeOH solution. The trimeric chiral ligand L3 has been shown to be an efficient auxiliary in a Zn(II)-mediated enantioselective Henry reaction.