Asymmetric NaBH<sub>4</sub>1,4-Reduction of C3-Disubstituted 2-Propenoates Catalyzed by a Diamidine Cobalt Complex
作者:Yoshihiro Shuto、Tomoya Yamamura、Shinji Tanaka、Masahiro Yoshimura、Masato Kitamura
DOI:10.1002/cctc.201500260
日期:2015.5.18
unique diamidine ligand catalyzes asymmetric NaBH4 reduction 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
独特的二am基配体的新Co络合物催化NaBH 4还原不对称还原C3-二取代的(E)和(Z)-2-丙烯酸酯,包括具有高对映选择性的C3-氧和氮取代的底物。X射线衍射,1 H NMR光谱,开环自由基钟和D标记反应以及结构/选择性关系的分析表明,CoH参与的非单电子转移1,4加成的机理有所不同C2对映体。新型CoH 2(BH 3)2配合物的定量分离已支持了CoH物种的参与。