Cobalt(II)-Salen-Linked Complementary Double-Stranded Helical Catalysts for Asymmetric Nitro-Aldol Reaction
Cobalt(II)-Salen-Linked Complementary Double-Stranded Helical Catalysts for Asymmetric Nitro-Aldol Reaction
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DOI：
10.1021/acscatal.6b01627
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发表时间：
2016-07-01
期刊：
影响因子：
12.9
通讯作者：
Yashima, Eiji
中科院分区：
文献类型：
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作者：
Taura, Daisuke;Hioki, Shogo;Yashima, Eiji
双螺旋、双手性Co（II）-salen配合物通过手性脒-羧酸盐桥稳定，有效地催化了不对称硝基羟醛缩合（亨利）反应，产物的对映体过量（ee）高达89%，反应活性和对映体选择性均高于相应的单链催化剂.手性双螺旋骨架在超分子手性催化中的关键作用已被一个双螺旋催化剂所揭示，该催化剂携带非手性Co（II）-salen单元，促进了亨利反应，得到具有50%-45% ee的产物，而相应的单链显示出差的或没有对映选择性。
Double-helical, bimetallic chiral Co(II)-salen complexes stabilized by chiral amidinium-carboxylate salt bridges efficiently catalyzed the asymmetric nitro-aldol (Henry) reaction, producing products with up to an 89% enantiomeric excess (ee); the reactivity and enantioselectivity were higher than those catalyzed by the corresponding single strands. The key role of the chiral double-helical framework for the supramolecular bimetallic catalysis has been revealed by a double-helical catalyst carrying achiral Co(II)-salen units that promoted the Henry reaction, yielding the product with a 50%-45% ee, while the corresponding single strands showed poor or no enantioselectivity.