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
Asymmetric Henry reactions of aldehydes with various nitroalkanes catalyzed by copper(II) complexes of novel chiral<i>N</i>-monoalkyl cyclohexane-1,2-diamines
作者:Fei Liu、Shaohua Gou、Lei Li
DOI:10.1002/aoc.3107
日期:2014.3
2‐diamine (3g), the reaction was optimized in terms of the metal ion, temperature, solvent and base. Further experiments indicated that the complex, 3g–Cu(OAc)2, was an efficient catalyst in the asymmetricHenryreaction between different aldehydes and nitromethane, and the desired products have been obtained with high chemical yields (up to 99%) and high enantiomeric excess (up to 93%). The optimized catalyst
Enantioselective Henry reaction catalyzed by C2-symmetric chiral diamine–copper(II) complex
作者:Sermadurai Selvakumar、Dhanasekaran Sivasankaran、Vinod K. Singh
DOI:10.1039/b904254g
日期:——
A copper(II) complex of C2-symmetric diamine has been proved to be an efficient catalyst for the enantioselective Henry reaction between nitroalkanes and various aldehydes to provide β-hydroxy nitroalkanes in high yields (up to 97%), moderate diastereoselectivities (up to 71:29) and excellent enantiomeric excesses (up to 96%). The chiral nitroaldol adduct obtained has been further converted into chiral
2‐endo‐substituted and 2‐endo,N‐fused bi‐ and tricyclic bispidines. The new diamines were evaluated as the chiral ligands in asymmetricHenryreactions. Excellent enantioselectivities of up to 99 % ee and good diastereomeric ratios of up to 86:14 were reached with a copper(II) complex modified by a 2‐endo,N‐(3,3‐dimethylpyrrolidine)‐annelated bispidine. Its performance is superior to that of the well‐known bispidines
Enantioselective Henry and Aza-Henry Reaction in the Synthesis of (<i>R</i>)-Tembamide Using Efficient, Recyclable Polymeric Cu<sup>II</sup>Complexes as Catalyst
作者:Anjan Das、Manoj K. Choudhary、Rukhsana I. Kureshy、Tamal Roy、Noor-ul H. Khan、Sayed H. R. Abdi、Hari C. Bajaj
DOI:10.1002/cplu.201402078
日期:2014.8
Chiral copper(II) polymeric [H4]salen (salen=bis[(salicylidene)ethylenediaminato]) complexes CuII‐1–3 were generated in situ and used as efficient catalysts in the asymmetric Henry and aza‐Henry reaction of various aromatic and aliphatic aldehydes and N‐tosylimines in the presence of various nitroalkanes at room temperature (27±2 °C) for 20 hours. This group of polymeric [H4]salen complexes demonstrated
手性铜(II)的聚合物[H 4 ]沙仑(沙仑=双[(亚水杨基)ethylenediaminato])配合物的Cu II -1 - 3原位产生和用作在不对称亨利有效的催化剂和各种芳族的氮杂-亨利反应在室温(27±2°C)下,在各种硝基烷存在下,脂肪族醛和N-甲苯基亚胺为20小时。这组聚合的[H 4 ] salen配合物通过使用低催化剂负载量为1 mol%(相对于单体salen)的硝基甲烷,在形成β-硝基醇方面表现出优异的性能(产品收率和对映体过量 ee高达98%)单位)和高对映体诱导(ee 94%)在aza-Henry产品中;以中等产率(78%)获得了β-硝胺。该催化系统也与硝基乙烷和亨利反应的情况下1-硝基丙烷运作良好,以提供在高收率和对映选择性的相应的产品顺式非对映体。该铜II -2复杂的克水平保持其性能,并在其性能没有显著损失方便回收的八倍。Cu II -2配合物对N的对映选择性氮杂-