Silica vanadic acid [SiO₂–VO(OH)₂] as an efficient heterogeneous catalyst for the synthesis of 1,2-dihydro-1-aryl-3H-naphth[1,2-e][1,3]oxazin-3-one and 2,4,6-triarylpyridine derivatives via anomeric based oxidation

Experimental and theoretical studies of the nanostructured {Fe3O4@SiO2@(CH2)3Im}C(CN)3catalyst for 2-amino-3-cyanopyridine preparationviaan anomeric based oxidation

“…Previously reported studies have been proposed aerobic auto oxidation of intermediate (7) to its corresponding 2-amino-3-cyanopyridines (1). In contrast to the previously reported mechanistic description for the final step of the above described organic synthesis [33], we believed that, this step might be progress through uncommon hydride transfer as well as Cannizzaro reaction (Scheme 3) [37] and H 2 releasing from tricyclic orthoamide which presented in Scheme 4 [35]. Very recently, we proposed an anomeric based oxidation for the final step in mechanistic pathways of 1,4-dihydropyrano-[2,3-c]-pyrazole [36] and 2,4,6-triarylpyridine [37] derivatives synthesis (Schemes 5 and 6).…”

“…To the best of our knowledge, this phenomena has been named as anomeric effect. Very recently, we have introduced a new term entitled "Anomeric Based Oxidation (ABO)" for the above mentioned facts so that oxidation of various substrates were occurred via releasing of molecular hydrogen [35,37]. Fourtunately, experimental evidences and theoretical studies confirmed that the final step of the synthetic pathway is proceeded via an anomeric based oxidation mechanism.…”

“…Scheme 3. The proposed mechanism for the in-situ oxidation-reduction in Cannizzaro reaction through unusual hydride transfer viaanomericeffect [37] In a proposed mechanism, as portrayed in Scheme 7. the cationic site of the {Fe 3 O 4 @SiO 2 @(CH 2 ) 3 Im}C(CN) 3 plays a crucial role in activating of aromatic aldehydes and acetophenones as electrophile species and also at the same time the anionic site of the catalyst could interact with acidic hydrogen in malononitrile to trigger nucleophilic addition. Afterward, the reaction moves forward via the interaction between enamine 2 (generated from the reaction of ketone and ammonium acetate) and alkylidene malononitrile 3 (generated from the reaction of aldehyde and malononitrle) to yield the corresponding intermediate [38].…”

1,10‐Phenanthroline‐Based Molten Salt as a Bifunctional Sulfonic Acid Catalyst: Application to the Synthesis of N‐Heterocycle Compounds via Anomeric Based Oxidation

“…Very recently we have introduced a new concept entitled “anomeric based oxidation (ABO) ” susceptible molecules and intermediates which can released H 2 in the presence of acidic catalysts . Based on this concept, driving force of aromatization to support losing H 2 molecule from intermediate ( III ) via anomeric based oxidation (ABO) and the desired product was obtained (Scheme ).…”

Facile one‐pot synthesis of a series of 7‐aryl‐8H‐benzo[h]indeno[1,2‐b]quinoline‐8‐one derivatives catalyzed by cellulose‐based magnetic nanocomposite

“…Then, an intermediate was formed from 1 ‐ naphthylamine and 1,4 ‐ dihydroquinoline during ring formation by removing an H 2 O molecule. In the final step, MCSA‐promoted the oxidation of 1,4 ‐ dihydroindenoquinolines to the target product indenoquinolines (Scheme ).…”