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.
C3-Symmetric cinchonine-squaramide as a recyclable efficient organocatalyst for tandem Michael addition–cyclisation of malononitrile and nitrovinylphenols
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 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.