One-pot Synthesis of Terminal Vinylphosphonates Catalyzed by Pyridine Grafted GO as Reusable Acid-Base Bifunctional Catalyst

Abstract

Pyridine grafted graphene oxide (Py‐GO) as an acid‐base bifunctional catalyst was found to show cooperative catalysis in the one‐pot synthesis of vinylphosphonates. In the presence of this catalyst, a variety of vinylphosphonates were synthesized by the reaction of different aldehydes (aryl, heteroaryl and alkyl aldehydes), phosphite esters and nitromethane in water. The present method is the first report for the one‐pot synthesis of terminal vinylphosphonates using a reusable heterogeneous catalyst through a cascade Henry‐Michael reaction followed by nitro elimination. This protocol offers several advantages such as using a simplified one‐pot synthetic process with step saving, the least amount of waste, and low operational cost. Furthermore, the heterogeneous catalyst was successfully recovered and reused five times with unaltered catalytic activity.

Immobilized piperazine on the surface of graphene oxide as a heterogeneous bifunctional acid–base catalyst for the multicomponent synthesis of 2-amino-3-cyano-4H-chromenes

“…However, despite the excellent catalytic activity and reusability of bifunctional GO catalysts, only a few studies focused on the GO functionalization and its use as bifunctional GO catalysts in MCRs, even though this area has an immense potential. 35,[41][42][43][44][45][46] Please do not adjust margins )Please do not adjust margins Within heterocyclic compounds, 2-amino-3-cyano-4H-chromenes and their derivatives have attracted significant interest, because they are present in a wide variety of biologically active natural products and exhibit several pharmaceutical properties such as anti-allergic, anti-oxidant and antibacterial. [47][48][49][50] These compounds have also been known as spasmolytic, anti-malaria, diuretic, anti-cancer, anti-HIV, anti-Alzheimer, anti-coagulant, and anti-anaphylactic agents.…”

Immobilized Lanthanum(III) Triflate on Graphene Oxide as a New Multifunctional Heterogeneous Catalyst for the One-Pot Five-Component Synthesis of Bis(pyrazolyl)methanes

“…Taking advantage of multifunctional catalysts in one-pot tandem reactions and further development of work in our laboratory on the introduction of newly synthesized heterogeneous catalysts, − in this paper, we report the synthesis of immobilized lanthanum­(III) triflate on amine-grafted graphene oxide [La­(OTf) 2 -grafted-GO] as a new multifunctional catalyst (Scheme ). This catalyst is characterized by various methods such as FT-IR, XPS, TEM, FESEM, EDS, ICP, and solid-state 13 C MAS NMR and employed as the first reusable (Lewis and Brønsted) acid–base trifunctional catalyst for the tandem reaction of phenylhydrazine, ethyl acetoacetate, and arylaldehydes.…”