The clean synthesis and confirmatory structural characterization of new 2-amino-4,8-dihydropyrano[3,2-b]pyran-3-cyano based on Kojic acid

Fe3O4@silica‐MCM‐41@DABCO: A novel magnetically reusable nanostructured catalyst for clean in situ synthesis of substituted 2‐aminodihydropyrano[3,2‐b]pyran‐3‐cyano

“…A proposed mechanism is presented in Scheme for the formation of 12a – 12o . In accordance with this mechanism, Fe 3 O 4 @MCM‐41@DABCO is an active nanocatalyst for the generation of 2‐arylidinemalononitriles.…”

“…In addition, polysubstituted 2‐aminodihydropyrano[3,2‐ b ]pyran‐3‐cyano derivatives are very important heterocyclic compounds, which often exhibit various pharmacological activities . In recent years, several procedures have been introduced for the efficient and easy production of the important structure of polysubstituted 2‐aminodihydropyrano[3,2‐ b ]pyran‐3‐cyano derivatives . However, the disadvantages of these approaches are long reaction times, harsh conditions, low product yields, tiresome workup and use of extra amounts of catalyst and reagents.…”

Organic Base-Promoted C–N- and C–O-Coupled Domino Cyclization Strategy: Syntheses of Oxazine-6-ones and 4-Pyrimidinols

“…Then, a nucleophilic attack of the imidate ( 2a ) toward the good Micheal acceptor dicyano-olefin ( 1a ) afforded the intermediate ( I ). Subsequently, a [1, 3]-H-abstraction occurs in the intermediate I to produce the intermediate II . In the next step, thiourea reacts with one cyano group of intermediate II , leading to the formation of intermediate III .…”

“…Then, a nucleophilic attack of the imidate (2a) toward the good Micheal acceptor dicyano-olefin (1a) afforded the intermediate (I). Subsequently, a [1, 3]-Habstraction 20 intermediate III. 21 Then, the lone pair of the O atom attacks the imine bond, and the weak C−S bond breaks and cyclizes to produce the intermediate IV.…”

Lentilactobacillus farraginis FSI (3): A whole cell biocatalyst for the synthesis of kojic acid derivative under aquatic condition

“…Although papers are found in the literature for the synthesis of kojic acid derivatives using aldehyde, kojic acid, and malononitrile. Through chemical methods employing chemical catalyst like MCM-41-SO3H (Sarra et al 2021), Fe3O4@SiO2-BenzIm-Fc(Cl)/ZnCl2 (Teimuri-Mofrad et al 2017), NH4Cl (Aghbash et al 2018), Fe3O4@SiO2-s-triazinium chloride (Azarifar et al 2019) that demands high temperature or cosolvent system. The nanoparticles like Cobalt nanoparticles (Hossein Banitaba 2019), Cuprous Oxide-Zeolite clinoptilolite nanoparticles (Baghbanian 2014), nano Fe3O4@SiO2-IL-Fc (Teimuri-Mofrad et al 2017) are also used as a catalyst for the synthesis of kojic acid derivatives.…”