α-(杂芳基)-α-烷基氰基乙酸酯的不对称合成是在两种类型的手性配体(( S )-nobin-体现的吡啶甲酰胺和L-羟基脯氨酸衍生的手性配体的帮助下,通过铜催化α-烷基取代的氰基乙酸酯的芳基化来实现的。酰胺。该反应提供了带有全碳四元中心并与可转换官能团连接的偶联产物,具有良好至优异的对映选择性(高达 95% ee)。
Highly enantioselective 1,4-conjugate addition of diethylzinc to acyclic enones with chiral phosphite–pyridine ligands derived from H8-NOBIN
作者:Yuanchun Hu、Xinmiao Liang、Junwei Wang、Zhuo Zheng、Xinquan Hu
DOI:10.1016/j.tetasy.2003.09.020
日期:2003.12
A series of new phosphite-pyridine ligands, based on the H-8-binaphthyl backbone, were synthesized and employed in the copper-catalyzed enantioselective 1,4-conjugate addition of diethylzinc to acyclic enones. Ligands derived from (S)-H-8-NOBIN provided better results than their parent ligands in the reaction. Ligand L1 provided excellent ees for trans -4-aryl-3-buten-2-ones (up to 97.8% ee) as substrates. Ligand L2 was very efficient for various para-chalcones, and up to 97.2% ee was achieved. (C) 2003 Elsevier Ltd. All rights reserved.
Readily Prepared Chiral P,N Ligands and Their Applications in Cu-Catalyzed Enantioselective Conjugate Additions
作者:Yuanchun Hu、Xinmiao Liang、Junwei Wang、Zhuo Zheng、Xinquan Hu
DOI:10.1021/jo0340758
日期:2003.5.1
A new type of phosphite-pyridine (P,N) ligand derived from (S)-NOBIN and (S)-BINOL was employed in Cu(I)-catalyzed conjugate addition of diethylzinc to chalcones. The new P,N ligands were highly efficient in the copper-catalyzed enantioselective 1,4-conjugate additions of diethylzinc to acyclic enones, and up to 97% ee was achieved.
Nonlinear effects in the enantioselective 1,4-conjugate addition of diethylzinc to chalcone
作者:Yuanchun Hu、Xinmiao Liang、Zhuo Zheng、Xinquan Hu
DOI:10.1016/j.tetasy.2003.07.001
日期:2003.9
A clear positive nonlinear effect of the enantiopurity of ligand 1 on the product ee was observed in the enantioselective 1,4-conjugate addition of Et2Zn to chalcone. The experimental data of nonlinear effect meet Kagan's ML2 model. (C) 2003 Elsevier Ltd. All rights reserved.