An efficient protocol for the one-pot multicomponent synthesis of polysubstituted pyridines by using a biopolymer-based magnetic nanocomposite

Abstract

A biopolymer cellulose-based magnetic composite nanocatalyst was prepared and characterized by using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX). Then, it was used efficiently in the multicomponent synthesis of polysubstituted pyridines under mild reaction conditions and using an easy work-up procedure at room temperature in ethanol. The nanocatalyst can be recovered easily and reused several times without significant loss of catalytic activity.

Ultrasound-promoted green approach for the synthesis of multisubstituted pyridines using stable and reusable SBA-15@ADMPT/H5PW10V2O40nanocatalyst at room temperature

“…Therefore, the development of new procedures for their synthesis is still a desirable goal. Due to the wide range of applications and pharmacological activity of 2-amino-3-cyanopyridine derivatives, a variety of reagents and catalysts such as ytterbium perfluorooctanoate [Yb(PFO) 3 ] (37), Graphene oxide (38), 2,2,2-trifluoroethanol (39), Fe 3 O 4 /cellulose (40), ionic liquids (41), and Au/MgO (42) have been reported for the synthesis of these compounds. However, most of these procedures suffer from one or more drawbacks such as the use of expensive metal catalysts, harsh reaction conditions, tedious multistep syntheses, use of toxic solvent, complicated reaction procedures.…”

Synthesis of cobalt tetra-2,3-pyridiniumporphyrazinato with sulfonic acid tags as an efficient catalyst and its application for the synthesis of bicyclic ortho-aminocarbonitriles, cyclohexa-1,3-dienamines and 2-amino-3-cyanopyridines

“…According to the previously proposed mechanism for the synthesis of products 8 or 9, reaction were proceeded by aerobic auto oxidation of 13 0 to products 8 or 9 (Scheme 5). [23][24][25] In contrast to our expected products 13 0 , we observed that 13 0 was converted to 2-amino-3-cyanopyridines (8 and 9) via a hydride transfer which was named anomeric based oxidation (ABO) as well as Cannizzaro reaction (Scheme S1 †), H 2 releasing from tricyclic orthoamide (Scheme S2 †) and etc. [34][35][36][37][38] For this reason, reaction was performed without any molecular oxygen under nitrogen and argon atmospheres.…”

“…A possible mechanism for the synthesis of 8 or 9 is described in Scheme 5. [23][24][25] Firstly, [Co(TPPASO 3 H)]Cl activates the aldehyde 1 and malononitrile 2 to provide intermediate 1 0 and 2 0 , respectively. The Knoevenagel condensation between 1 0 and 2 0 was happened to produce the arylidenemalononitrile 10.…”

“…17 2-Amino-3-cyanopyridines are signicant compounds due to their biological and pharmaceutical activities include antitumor properties, 18 anti-parkinsonism, 19 cardiotonic 20 and anti-inammatory. 21,22 A wide range of approaches for the synthesis of these compounds are being reported in the literature by numerous catalysts such as Fe 3 O 4 @niacin, 23 Fe 3 O 4 / cellulose nanocomposite 24 and Yb(PFO) 3 . 25 On the other hand, the role of negative hyperconjugation in a classic conformational preference, which has been named anomeric effect, is a paramount important on the structure and reactivity of a wide variety of organic functional groups.…”

Earth-Abundant d-Block Metal Nanocatalysis for Coupling Reactions in Polyols

“…condensation between the aromatic aldehyde and dimedone; the resulting α,βunsaturated ketone reacts with the 2-aminobenzimidazole or its corresponding thioderivative via a Michael addition, giving an acyclic compound which undergoes a further intramolecular cyclization. Similar catalysts were also applied for the synthesis of 2-amino-4H-chromenes [107] and highly substituted pyridines [84].…”