One-pot synthesis of some 2-amino-4H-chromene derivatives using triethanolamine as a novel reusable organocatalyst under solvent-free conditions and its application in electrosynthesis of silver nanoparticles
2-amino-4H-chromene derivatives. Its advantages include short reaction time, high yields, low cost, and straightforward work-up. Triethanolamine is an efficient reusable catalyst. 2-Amino-4H-benzo[g]chromenes (ABgC) were applied as novel components of electro synthesis of silver nanoparticles.
Novel multi-cationic ionic liquids containing a mesitylene backbone with acetate and methane sulphonate anions have been synthesized. These ionic liquids were used for the synthesis of 2-amino-4H-chromenes under microwave heating. The effects of nature and amount of ionic liquids on the yield and reaction time were thoroughly investigated. The ionic liquids showed a considerable level of reusability
The preparation of pharmaceutically active 2-amino-4H-chromene derivatives has been achieved using a nano powder of natural clinoptilolite (CP) zeolite. A wide range of these worthy structures having diverse substituents on the 4H-chromene ring were efficiently synthesized via the reaction of an aromatic aldehyde and variety of enolizable C–H activated acidic compounds. Nano sized natural clinoptilolite
DBU: a highly efficient catalyst for one-pot synthesis of substituted 3,4-dihydropyrano[3,2-c]chromenes, dihydropyrano[4,3-b]pyranes, 2-amino-4H-benzo[h]chromenes and 2-amino-4H benzo[g]chromenes in aqueous medium
作者:Jitender M. Khurana、Bhaskara Nand、Pooja Saluja
DOI:10.1016/j.tet.2010.05.082
日期:2010.7
We have reported DBU catalyzedone-potsynthesis of 3,4-dihydropyrano[3,2-c]chromenes, dihydropyrano[4,3-b]pyranes, 2-amino-4H-benzo[h]chromenes and 2-amino-4H-benzo[g]chromenes from aldehydes, active methylene compounds malononitrile/ethyl cyanocacetate, and 4-hydroxycoumarin/4-hydroxy-6-methylpyrone/1-naphthol/2-hydroxynaphthalene-1,4-dione in water under reflux. The attractive features of this process
我们已经报道了DBU催化一锅合成3,4-二氢吡喃并[3,2- c ]苯并二氢吡喃并[4,3- b ]吡喃,2-氨基-4 H-苯并[ h ]苯并二胺回流下得自醛,活性亚甲基化合物丙二腈/氰基乙酸乙酯和4-羟基香豆素/ 4-羟基-6-甲基吡喃酮/ 1-萘酚/ 2-羟基萘-1,4-二酮的-4 H-苯并[ g ]色酮。该方法的吸引人的特征是温和的反应条件,反应介质的可重复使用性,较短的反应时间,易于分离的产物以及优异的产率。
Imidazole as organocatalyst for multicomponent reactions: diversity oriented synthesis of functionalized hetero- and carbocycles using in situ-generated benzylidenemalononitrile derivatives
作者:Md. Nasim Khan、Suman Pal、Shaik Karamthulla、Lokman H. Choudhury
DOI:10.1039/c3ra45252b
日期:——
The multicomponent reaction of malononitrile, aldehyde and a third reaction partner such as naphthol/4-hydroxycoumarine/2-hydroxynaphthoquinone/kojic acid/enolizable ketone or thiol in the presence of imidazole as an organocatalyst provides very interesting molecular diversity. In an almost neutral reaction medium, this protocol provides easy access to highly functionalized 2-amino-4H-chromenes, dienes and 2-amino pyridines using in situ-generated aryl/alkylylidenemalononitrile derivatives obtained from the reaction of aldehydes and malononitrile along with various nucleophiles under reflux conditions in ethanol. This methodology is useful for the easy access of a wide range of structurally diverse functionalized molecules having potential application in biological systems.