Application of chiral N,N′-dialkyl-1,2-cyclohexanediamine derivatives in asymmetric copper(II)-catalyzed Henry reactions
作者:Zhao Chunhong、Fei Liu、Shaohua Gou
DOI:10.1016/j.tetasy.2013.12.017
日期:2014.2
A series of chiral N,N′-dialkyl-1,2-cyclohexanediamine derivatives were designed, synthesized, and applied as ligands in asymmetriccopper(II)-catalyzed Henryreactions. The catalysts based on such ligands and copper(II) acetate were found to promote asymmetricHenryreactions between aromatic/aliphatic aldehydes and nitromethane efficiently, and could provide the corresponding β-nitroalcohols in very
Synthesis of chiral salalen ligands and their in-situ generated Cu-complexes for asymmetric Henry reaction
作者:Ashish Dixit、Pramod Kumar、Surendra Singh
DOI:10.1002/chir.23019
日期:2018.12
Chiral salalen ligands derivedfrom (S)‐proline and derivatives of salicyaldehydes were synthesized, and their in‐situ generated Cu (II) complexes were evaluated in the asymmetric Henry reaction. Salalen ligand of different substituents on the phenyl moiety showed remarkable effect on the enantioselectivity of nitro‐aldol product of 4‐nitrobenzaldehyde and nitromethane. Cu (II) complex generated in
合成了衍生自(S)-脯氨酸和水杨醛衍生物的手性Salalen配体,并在不对称Henry反应中评估了它们原位生成的Cu(II)配合物。苯基部分上不同取代基的Salalen配体对4-硝基苯甲醛和硝基甲烷的硝基羟醛产物的对映选择性表现出显着影响。与(S)-2-(叔丁基)-6(((2-((((2-羟基-3-甲基苄基)氨基)甲基)吡咯烷烃-1-基)甲基)生成的Cu(II)络合物苯酚(10 mol%)和Cu(OAc)2 .H 2O(10 mol%)被发现是4-硝基苯甲醛与硝基甲烷之间硝基-羟醛反应的较好催化剂,40小时后,在35°C下,异丙醇中的相应产物收率为85%,对映体过量(ee)为88%。还以不同的取代的苯甲醛用于亨利反应的催化剂和相应的产物以22%至99%的产率和66%至92%的ee获得。4-硝基苯甲醛与前手性硝基乙烷的亨利反应产生抗选择性产物(dr = 79/21; anti / syn),收率为91%,ee为80%。
Synthesis of <i>C</i><sub>1</sub>-Symmetric Chiral Secondary Diamines and Their Applications in the Asymmetric Copper(II)-Catalyzed Henry (Nitroaldol) Reactions
作者:Yirong Zhou、Junfang Dong、Fanglin Zhang、Yuefa Gong
DOI:10.1021/jo102124d
日期:2011.1.21
A small library of C1-symmetric chiral diamines (L1−L9) was constructed via condensing exo-(−)-bornylamine or (+)-(1S,2S,5R)-menthylamine with various Cbz-protected amino acids. Among them, ligand L1/CuCl2·2H2O complex (2.5 mol %) shows outstanding catalytic efficiency for Henryreaction between a variety of aldehydes and nitroalkanes to afford the expected products in high yields (up to 98%) with
Abstract A series of chiral tridentate Schiff-base ligands and their polymer-supported ligands were conveniently prepared and introduced as copper(II) chiralcomplexes for the asymmetric Henry reaction. The structures of these ligands have been characterized by IR, 1 H NMR, 13 C NMR and MS. The experimental results showed that the corresponding β-nitro alcohols were obtained in moderate to high yields
摘要 一系列手性三齿席夫碱配体及其聚合物负载的配体被方便地制备并作为铜(II)手性配合物引入不对称亨利反应。这些配体的结构已通过 IR、 1 H NMR、 13 C NMR 和 MS 表征。实验结果表明,在温和条件下,以中等至高产率(高达98%)获得了相应的β-硝基醇,ee高达98%。由铜 (II) 聚合物负载的配体形成的复杂催化剂可以通过简单的过滤回收并至少重复使用 6 次,具有类似的良好催化效果(约 94% 的产率和 90% 的 ee)。
Synthesis of Chiral 1,3-Diamines Derived from cis-2-Benzamidocyclohexanecarboxylic Acid and Their Application in the Cu-Catalyzed Enantioselective Henry Reaction
作者:Koichi Kodama、Kazuyuki Sugawara、Takuji Hirose
DOI:10.1002/chem.201102136
日期:2011.11.25
decrease in product enantioselectivity caused by spontaneous retro‐Henryreaction, which was suppressed by conducting the reaction at 0 °C. This versatile reaction afforded various β‐nitroalcohols in excellent yields and enantioselectivities (up to 98 % yield, 91 % enantiomeric excess) under the optimized reaction conditions. The chiral induction mechanism was explained on the basis of a previously