C3-Symmetric cinchonine-squaramide as a recyclable efficient organocatalyst for tandem Michael addition–cyclisation of malononitrile and nitrovinylphenols
摘要:
The tandem enantioselective Michael addition/cyclisation reaction of malononitrile and nitrovinylphenols was catalysed by a recoverable C-3-symmetric cinchonine-squaramide organocatalyst la to afford the 2-amino-4H-chromene-3-carbonitrile derivatives in excellent yields (up to 95%) and with excellent enantioselectivities (up to 98% ee) under mild reaction conditions. Furthermore, this catalyst can be easily recovered four times without loss in activity or enantioselectivity. (C) 2016 Elsevier Ltd. All rights reserved.
Enantioselective synthesis of 2-amino-4-(nitromethyl)-4<i>H</i>-chromene-3-carbonitriles from 2-iminochromenes
作者:Gamze Koz、Omer Koz、Necdet Coskun
DOI:10.1080/00397911.2016.1177728
日期:2016.5.18
ABSTRACT A series of medicinally important 2-amino-4-(nitromethyl)-4H-chromene-3-carbonitriles were synthesized using enantioselective conjugateaddition of nitromethane to 2-iminochromenes. The reactions were performed using L8-Cu (II) catalytic system and moderate to good enantioselectivities (62–88%) and yields (66–96%) were obtained. GRAPHICAL ABSTRACT
摘要 利用硝基甲烷与 2-亚氨基色烯的对映选择性共轭加成,合成了一系列具有药用价值的 2-氨基-4-(硝基甲基)-4H-色烯-3-腈。使用 L8-Cu (II) 催化体系进行反应,获得了中等至良好的对映选择性 (62-88%) 和产率 (66-96%)。图形概要
Efficient organocatalytic asymmetric synthesis of 2-amino-4H-chromene-3-carbonitrile derivatives
作者:Yu Gao、Wen Yang、Da-Ming Du
DOI:10.1016/j.tetasy.2012.02.019
日期:2012.3
enantioselective tandem Michael addition–cyclization of malononitrile to nitroalkenes for the direct synthesis of chiral 2-amino-4H-chromene-3-carbonitrile derivatives was investigated. Good yields and enantioselectivities (up to 91% ee) were achieved. This organocatalytic asymmetric tandem Michael addition–cyclization provides an efficient routetoward the synthesis of optically active functionalized chromenes
Highly efficient enantioselective three-component synthesis of 2-amino-4H-chromenes catalysed by chiral tertiary amine-thioureas
作者:Gaosheng Yang、Chongrong Luo、Xiaolong Mu、Tingting Wang、Xin-Yuan Liu
DOI:10.1039/c2cc30731f
日期:——
A three-component cascade reaction of salicylaldehyde, malononitrile/cyanoacetate and nitromethane catalysed by chiral tertiary amino-thioureas was developed, which leads to the production of highly functionalized 2-amino-4H-chromenes in good yields with good to excellent enantioselectivities.
Chiral bifunctional squaramide catalyzed asymmetric tandem Michael-cyclization reaction: efficient synthesis of optically active 2-amino-4H-chromene-3-carbonitrile derivatives
We have developed an efficient bifunctional squaramide catalyst for the asymmetric tandem Michael addition-cyclization of malononitrile to functionalized nitroolefins. This organocatalytic asymmetric reaction provides convenient and valuable access to highly functionalized 2-amino-4H-chromene derivatives, which possess important biological activities, in good yields with moderate to high enantioselectivities (up to 95% ee). (C) 2013 Elsevier Ltd. All rights reserved.
Enantioselective organocatalytic synthesis of medicinally privileged 2-amino-4H-chromene-3-carbonitriles via a cascade process
作者:Zhiyun Du、Woon-Yew Siau、Jian Wang
DOI:10.1016/j.tetlet.2011.09.030
日期:2011.11
An efficient organocatalytic cascade approach toward medicinally privileged 2-amino-4H-chromene-3-carbonitriles is reported. The enantioselective synthesis of these compounds is achieved in high yields and good to high ee values (up to 96% yield and 89% ee) using bifunctional amine-thiourea organocatalysts developed in our laboratory. (C) 2011 Elsevier Ltd. All rights reserved.