Biological based (nano) gelatoric ionic liquids (NGILs): Application as catalysts in the synthesis of a substituted pyrazole via vinylogous anomeric based oxidation

A Convenient Catalytic Method for the Synthesis of Pyridines with Henna and Pyrazole Moieties using Cooperative Vinylogous Anomeric‐Based Oxidation

“…Intramolecular cyclization of ( ІІ ) generates intermediate ( ІІІ ) and then converts to ( IV ) and finally the related product ( V ) synthesized by a cooperative vinylogous anomeric based oxidation (Scheme 5). [36,37] Recently, catalytic anomeric an‐based oxidation has been reviewed by Yarie and co‐workers [59] . According to the reported mechanistic path for the final step of the above‐mentioned suggested mechanism in the literature (Schemes S 1 and S 2 ), [60–62] we proposed that the final step could be carried out via an unexpected hydride transfer reaction and realizing one H 2 molecule by a vinylogous anomeric based oxidation stage.…”

“…[33] According to the above mentioned, the electron transfers from hetero atoms lone pair orbitals to the CÀ H vacant antibonding sigma orbital (n N !σ*CÀ H) can lead to increased shielding and decreased the chemical shift of its corresponding protons which are anti periplanar to lone pairs electrons of nitrogens (Scheme 2). [33,35] With the aim of overcoming the revealed problems in the preparation of pyrazolo [3,4-b]quinolinesand to develop the ChemistrySelect new concept "cooperative vinylogous anomeric based oxidation (VABO)", [36][37][38][39] herein we have synthesized [Fe 3 O 4 @SiO 2 (CH 2 ) 3 ][DABCO-H][C(CN) 3 ] 2 and used as a heterogeneous nanomagnetic catalyst for the reaction of several aldehydes with 3methyl-1-phenyl-1H-pyrazol-5-amine and 2-hydroxy naphthalene-1,4-dione to combine pyrazolo [3,4-b]quinolines. Magnetic catalysts are of great interest because of their ability to be easily separated and reused in organic reactions.…”

“…With the aim of overcoming the revealed problems in the preparation of pyrazolo[3,4‐b]quinolinesand to develop the new concept “cooperative vinylogous anomeric based oxidation (VABO)”, [36–39] herein we have synthesized [Fe 3 O 4 @SiO 2 (CH 2 ) 3 ][DABCO‐H][C(CN) 3 ] 2 and used as a heterogeneous nanomagnetic catalyst for the reaction of several aldehydes with 3‐methyl‐1‐phenyl‐1H‐pyrazol‐5‐amine and 2‐hydroxy naphthalene‐1,4‐dione to combine pyrazolo[3,4‐b]quinolines. Magnetic catalysts are of great interest because of their ability to be easily separated and reused in organic reactions [40] .…”

Pd(0)‐guanidine@MCM‐41: a very effective catalyst for rapid production of bis (pyrazolyl)methanes

“…Pyrazoles or pyrazolones [e.g. bis (pyrazolyl)methanes] are a significant category of bioactive drug goals in the pharmaceutical industry that show a variety of biological and medicinal activities, such as anti‐HIV, antiviral, gastric secretion stimulatory, antifilarial, antioxidant, antihypertensive, anticancer, anti‐inflammatory, antimalarial, antidepressant, antimicrobial, antipyretic and antibacterial properties. There are two ways to prepare bis (pyrazolyl)methanes: (i) the one‐pot pseudo five‐component reaction among phenylhydrazine, ethyl acetoacetate and aromatic aldehydes; and (ii) the one‐pot pseudo three‐component reaction between 3‐methyl‐1‐phenyl‐1H‐pyrazol‐5(4H)‐one and aromatic aldehydes.…”

Synthesis of a novel and reusable biological urea based acidic nanomagnetic catalyst: Application for the synthesis of 2‐amino‐3‐cyano pyridines via cooperative vinylogous anomeric based oxidation

“…In these situations, anomeric effect leads to axial preference for acceptor groups at the anomeric positions (Scheme 1). [53] In this paper, in the following of our interest to expand new established term entitled anomeric based oxidation (ABO) [61][62][63][64][65][66][67][68][69] and also presenting new and efficient protocols for synthesis of biological valuable structures using nanomagnetic based catalysts, [70][71][72][73][74][75][76][77][78][79] we reported the rational design, synthesis, characterization and catalytic performance of a novel biological urea based nano magnetic catalyst namely Fe 3 O 4 @SiO 2 @(CH 2 ) 3 -urea-benzimidazole sulfonic acid in the synthesis of 2-amino-3-cyano pyridines via vinylogous anomeric based oxidation pathway (Scheme 5, 6). In triazaphenalene three anomeric interactions assisted the hydride removal and generated a stable guanidinium cation in acidic conditions (Scheme 2).…”