Synthesis of Pyrazolo‐[4́,3́:5,6]pyrido[2,3‐d]pyrimidine‐diones Catalyzed by a Nano‐sized Surface‐Grafted Neodymium Complex of the Tungstosilicate via Multicomponent Reaction

Abstract

An inorganic–organic hybrid based on lanthanide clusters and Keggin type polyoxometalates (POMs) (Na[Nd (pydc‐OH)(H2O)4]3}[SiW12O40]) was used the first time as trinuclear catalyst for one pot synthesis of pyrazolo[4́́,3́:5,6]pyrido[2,3‐d]pyrimidine‐diones, via two different four and five‐component reactions involving hydrazine hydrate, ethyl acetoacetate, aryl aldehydes, and 6‐amino‐1,3‐dimethyl uracil or barbituric acid with ammonium acetate as alternative materials in green condition. To evaluate potential application of the as‐made hybrid in adsorption and separation processes, nitrogen adsorption was performed at 77 K through simulation study. The hybrid catalyst was further characterized via powder X‐ray diffraction (PXRD) at room temperature which indicated the good phase purity of the catalyst. The results show that the catalytic activity of the hybrid catalyst has increased relative to each parent component due to the special interaction between Keggin anions and pydc‐OH ligands.

Novel neodymium complex on MCM‐41 magnetic nanocomposite as a practical, selective, and returnable nanocatalyst in the synthesis of tetrazoles with antifungal properties in agricultural

“…[24][25][26][27][28][29] Despite, although neodymium has been used for polymerization reactions due to its good catalytic activity, [30][31][32][33][34][35] this metal has rarely been used as a catalyst in the synthesis of organic compounds. [36][37][38] Therefore, for comply with the green chemistry principles and recycling of practical catalysts, MCM-41 MNC has been used as support for the preparation of practical and magnetically reusable nanocatalysts (Nd-LArg-5BrSalen@MNC), which shows both the utility of Fe 3 O 4 MNPs and MCM-41 nanopores including easy magnetically separation and highly surface area simultaneously. [4,21] In continuation, we investigated the application of this catalyst in the synthesis of tetrazole compounds, since tetrazole compounds have very much biological attributes.…”

Heterogeneous Catalysis by Polyoxometalates in Metal–Organic Frameworks

“…27 In addition, Lewis acidity can be achieved using high-valent metal centers with unoccupied d orbitals. 28,29 The oxidative activity of POMs can be tuned by using easily reducible metal sites, so often POM chemists turn to vanadium-substituted POMs for advanced oxidation processes. 30 POM functionalization is possible by incorporation of metal ions from throughout the periodic table, a universal concept that has been used for applications from catalysis and energy conversion to molecular electronics, nanomaterials design, biology, and medicine.…”

“…While POMs are known for their Brønsted acidity, , their structures can be tuned to make the POMs reactive Brønsted base catalysts by introducing high-charge-density terminal oxido ligands . In addition, Lewis acidity can be achieved using high-valent metal centers with unoccupied d orbitals. , The oxidative activity of POMs can be tuned by using easily reducible metal sites, so often POM chemists turn to vanadium-substituted POMs for advanced oxidation processes . POM functionalization is possible by incorporation of metal ions from throughout the periodic table, a universal concept that has been used for applications from catalysis and energy conversion to molecular electronics, nanomaterials design, biology, and medicine. − In addition, covalent attachment of organic groups to POMs is possible using suitable anchoring groups (phosphonates, sianols, carboxylates), so that linkage of metal oxide and organic chemistry − / metal complex chemistry − becomes possible.…”

Arsenomolybdates for Photocatalytic Degradation of Organic Dyes

“…Hill et al started systematic investigation of photoredox catalysis using POMs in the 1980s [14]. Accordingly, POMs photocatalysis has been applied to a wide range of reactions, including H 2 evolution, O 2 evolution, CO 2 reduction, metal reduction, and the degradation of organic pollutants and dyes [15][16][17][18][19][20].…”