Designing of Ultrafine PdNPs Immobilized Pyridinic‐NDoped Carbon and Evaluation of its Catalytic Potential for Konevenagel Condensation, Synthesis of 4H‐pyran Derivatives and Nitroreduction

Abstract

We report the desiging of ultrafine Pd‐based nanocatalyst containing N‐doped carbon structure (Pd@NC). The material was prepared by direct dehydration at 120 °C followed by mixing and heating with a dopant (ammonium oxalate) at 150 °C in a furnace. The Pd@NC nanocatalyst containing electron‐rich pyridinic‐N doped carbon structure, was thoroughly characterized by various techniques namely SEM, EDX, TEM, FTIR, ICP‐AES, XRD, XPS, TGA and Raman spectroscopy. The utility of the Pd@NC nanocatalyst was explored for base‐free Knoevenagel condensation and 4H‐pyran derivatives and also in the reduction of nitroarenes under mild and greener conditions. Further, the optical property was explored using photoluminescence spectroscopy and band gap was also calculated. The heterogeneous nature and stability of the catalyst facilitated by its ease of separation for long‐term performance and recycling studies showed that catalyst was robust and remained active upto six recycling experiments. Also, the leaching of metal was confirmed by ICP‐AES. The superiority of the catalyst was attributed to the metal support interaction (MSI) between metallic palladium and pyridinic‐N doped carbon to acquire excellent catalytic activity and changing the reducing nature of NaBH4 towards nitro functionality. The MSI between pyridinic‐N dopant on the carbon structure and PdNPs produces highly active sites for catalytic performance under mild conditions.

Palladium nanoparticles loaded over sheet-like N-doped graphene oxide: investigation of its catalytic potential in Suzuki coupling, in reduction of nitroarenes and in photodegradation of methyl orange

“…38 The peak around 261 represents the graphitic carbon, which has been diffracted from the (002) plane. 39,40 The size of Pd@NGO can be calculated using the Debye-Scherrer equation shown as:…”

Recent Advances on Heteroatom‐Doped Porous Carbon/Metal Materials: Fascinating Heterogeneous Catalysts for Organic Transformations

“…Gupta and coworkers disclosed an environmentally benign and simple procedure for the preparation of Pd nanocatalyst containing pyridinic‐ N doped carbon structure (Pd@NC) through dehydration of maltose in the attendance of H 2 SO 4 , heating with ammonium oxalate at 150 °C, and followed by the deposition of Pd NPs that were synthesized by the reduction of palladium acetate (Figure 77). [38b] The Pd@NC catalytic potential was evaluated for Konevenagel condensation (Scheme 119), synthesis of 4 H‐ pyran derivatives, the reduction of nitro compounds as well as oxidation of 5‐hydroxymethylfurfural. It has been found that excellent catalytic activity mainly resulted from the metal‐support interaction between Pd NPs and pyridinic‐ N dopant on the carbon structure.…”

Investigation into Solubility and Solvent Effect of 2-Aminopyridine in Different Mono-Solvents Over Temperatures from 273.15 to 313.15 K

“…no., 504-29-0; structure, Figure ) is widely employed in a variety of applications of pharmaceuticals’ synthesis, especially for antihistamines, antiflammatories, and other drugs. , Brominated 2-aminopyridine attracted considerable attention for its applications as useful intermediates or building blocks for pharmaceuticals. − In particular, 2-aminopyridine also serves as an useful raw material for some liquid crystals. , Regardless of its wide applications, there has been little research into the thermodynamic properties of 2-aminopyridine in neat and mixed solvents. 2-Aminopyridine is generally obtained through the reduction of 2-nitropyridine or 2-halopyridine in various solvents such as ethanol, , methanol, acetonitrile, N -methyl-2-pyrrolidine (NMP), and so on. Therefore the solubility of 2-aminopyridine in various solvents has a significant impact on product yield.…”

“…10,11 Regardless of its wide applications, there has been little research into the thermodynamic properties of 2-aminopyridine in neat and mixed solvents. 2-Aminopyridine is generally obtained through the reduction of 2-nitropyridine or 2-halopyridine in various solvents such as ethanol, 12,13 methanol, 14 acetonitrile, 15 Nmethyl-2-pyrrolidine (NMP), 16 and so on. Therefore the solubility of 2-aminopyridine in various solvents has a significant impact on product yield.…”