The imino Diels–Alderreaction is an efficient method for the synthesis of aza‐heterocycles. While different stereo‐ and enantioselective inverse‐electron‐demand imino Diels–Alder (IEDIDA) reactions have been reported before, IEDIDA reactions including electron‐deficient dienes are unprecedented. The first enantioselective IEDIDA reaction between electron‐poor chromone dienes and cyclic imines, catalyzed
Cascade reactions between 2-substituted-3-(4-oxo-4H-chromen-3-yl)acrylonitriles with benzylamine and p-toluidine
作者:Magdy A. Ibrahim、Al-Shimaa Badran
DOI:10.24820/ark.5550190.p010.745
日期:——
Abstract Chemical transformations of the simple condensation products derived from 3-formylchromone and some active methylene compounds, was achieved by reaction with nucleophilicreagents namely benzylamine and p-toluidine to produce either 2-iminopyrane or pyrano[3,2-c]chromene derivatives. These transformations initially proceed through nucleophilic attack at C-2 of the γ–pyrone ring with concomitant
A simple synthetic approach to the construction of novel 2-amino-5-mercapto-6-(mercaptomethyl)-4-aryl-4
<i>H</i>
-pyran-3-carbonitriles
作者:Tarik E. Ali、Mohammed A. Assiri
DOI:10.1080/17415993.2023.2249163
日期:2023.11.2
We discovered a simple syntheticapproach to the construction of novel 2-amino-5-mercapto-6-(mercaptomethyl)-4-aryl-4H-pyran-3-carbonitriles (3a-i) under metal-free conditions. The methodology depe...
A Mild and Efficient Route to 3-Vinylchromones in Aqueous Micellar Media
作者:Vikash Kumar、Amrita Chatterjee、Mainak Banerjee
DOI:10.1080/00397911.2015.1084008
日期:2015.10.18
A simple, mild, and ecofriendly method has been developed for the synthesis of 3-vinylchromones from 4-oxo-4H-1-benzopyran-3-carboxaldehyde (3-formylchromone) by simple Knoevenagel condensation with various active methylene compounds (AMC) in aqueous micellar media in the presence of catalytic amounts of cetyl trimethylammonium bromide (CTAB) and 1,4-diazabicyclo[2.2.2]octane (DABCO). In the case of malonic acid as AMC, the reaction resulted in formation of only Doebner decarboxylated products under the standard reaction condition. It has been also observed that 3-formylchromone derivatives primarily undergo tandem Knoevenagel and Michael reactions in the presence of >2 equiv. of ethyl acetoacetate to produce benzophenone derivatives, by opening of pyran ring, as the sole product in good yields.
Studies on the Chemical Transformations of Simple Condensates Derived from 3-Formylchromone under Nucleophilic Conditions