Asymmetric NaBH4 1,4-Reduction of C(3)-Disubstituted 2-Propenoates Catalyzed by a Diamidine Cobalt Complex
Asymmetric NaBH4 1,4-Reduction of C(3)-Disubstituted 2-Propenoates Catalyzed by a Diamidine Cobalt Complex
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二脒钴配合物催化 C(3)-二取代 2-丙烯酸酯的不对称 NaBH4 1,4-还原
DOI：
10.1002/cctc.201500260
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发表时间：
2015
期刊：
影响因子：
4.5
通讯作者：
Masato Kitamura*
中科院分区：
文献类型：
--
作者：
Yoshihiro Shuto;Tomoya Yamamura;Shinji Tanaka;Masahiro Yoshimura;Masato Kitamura*
一种独特的二脒配体的新型 Co 络合物可催化 C3-二取代的 (E)- 和 (Z)-2- 丙烯酸酯的不对称 NaBH4 还原，包括具有高对映选择性的 C3- 氧和氮取代底物。 X射线衍射、1H NMR光谱、开环自由基时钟和D标记反应以及结构/选择性关系的分析表明，CoH涉及的非单电子转移1,4加成机制区分了C2对映体。新型 CoH2(BH3)2 复合物的定量分离支持了 CoH 物种的参与。
A new Co complex of a unique diamidine ligand catalyzes asymmetric NaBH4reduction of C3‐disubstituted (E)‐ and (Z)‐2‐propenoates, including C3‐oxygen‐ and nitrogen‐substituted substrates with high enantioselectivity. Analysis by X‐ray diffraction,1H NMR spectroscopy, ring‐opening radical‐clock and D‐labeling reactions, and the structure/selectivity relationship suggest that a mechanism of CoH‐involved non‐single‐electron transfer 1,4‐addition differentiates the C2 enantioface. Involvement of CoH species has been supported by quantitative isolation of a new type of CoH2(BH3)2complex.