Synthesis of Nitriles from Aerobic Oxidation of Amines Catalyzed by Ruthenium Supported on Activated Carbon

Thapa

et al. 2019

Iodine and methylene blue adsorption properties of the high surface area nanoporous carbon materials derived from agro-waste and rice husk is reported. Rice husk was pre-carbonized at 300 °C in air followed by leaching out the silica nanoparticles by extraction with sodium hydroxide solution. The silica-free rice husk char was mixed with chemical activating agents sodium hydroxide (NaOH), zinc chloride (ZnCl2), and potassium hydroxide (KOH) separately at a mixing ratio of 1:1 (wt%) and carbonized at 900 °C under a constant flow of nitrogen. The prepared carbon materials were characterized by scanning electron microscopy (SEM), Fourier transformed-infrared spectroscopy (FT-IR), powder X-ray diffraction (pXRD), and Raman scattering. Due to the presence of bimodal micro- and mesopore structures, KOH activated samples showed high specific surface area ca. 2342 m2/g and large pore volume ca. 2.94 cm3/g. Oxygenated surface functional groups (hydroxyl, carbonyl, and carboxyl) were commonly observed in all of the samples and were essentially non-crystalline porous particle size of different sizes (<200 μm). Adsorption study revealed that KOH activated samples could be excellent material for the iodine and methylene blue adsorption from aqueous phase. Iodine and methylene blue number were ca. 1726 mg/g and 608 mg/g, respectively. The observed excellent iodine and methylene blue adsorption properties can be attributed to the well-developed micro- and mesopore structure in the carbon material. This study demonstrates that the agricultural waste, rice husk, and derived nanoporous carbon materials would be excellent adsorbent materials in water purifications.

Section: Introductionmentioning

confidence: 99%

Rice Husk-Derived High Surface Area Nanoporous Carbon Materials with Excellent Iodine and Methylene Blue Adsorption Properties

Thapa

et al. 2019

“…Later, Taube and co‐workers carried out a detailed study on the oxidation of different types of amine ligands coordinated to ruthenium centers . Based on these initial findings, numerous ruthenium catalyzed methods have been reported for the ODH of amines to nitriles (Table ) …”

Section: Ruthenium Catalystsmentioning

confidence: 99%

“…Increased conversions were observed in the continuous flow process (100%) compared to the batch process (92%), with increased selectivity towards benzonitrile (82% and 65%, respectively) . Recently, ODH of amines to the corresponding nitriles over Ru/AC (AC=Activated carbon) was reported …”

Section: Ruthenium Catalystsmentioning

confidence: 99%

Methods of Nitriles Synthesis from Amines through Oxidative Dehydrogenation

Patil

Gupta

2020

Adv Synth Catal

In recent years, oxidative dehydrogenation (ODH) of amines has proven to be an efficient, clean and fundamental route for the synthesis of nitriles. This review focuses on the different types of reactions for the oxidation of amines to nitriles such as transition metal-catalysis, photoactivation, acceptorless dehydrogenation, nitroxyl radical-mediated, and N,O-doped mesoporous carbon. Emphasis is placed on the ODH of amines to the corresponding nitriles using ruthenium catalysts. Metal free systems utilizing iodine, TEMPO and its derivatives, TCCA with or without additives are also discussed. The ODH of amines using N,O-doped mesoporous carbon is elaborated. Attention is also given to major improvements, achievements, and challenges that still remain in the field of nitrile synthesis from amines. 2.3. Photocatalytic System 2.4. Acceptorless Dehydrogenation (AD) 2.5. Substrate Scope and Functional Group Tolerance 3.

Chemistry An Asian Journal

“…Numerous heterogeneous ruthenium systems have also been reported for the production of nitriles and imines. [48][49][50][55][56][57][58][59][60] Kaneda et al reported am onomeric Ru 3 + species bound to ah ydroxyapatite surface (Ru/HAP), which acts as an efficient catalyst for the aerobic oxidationo fp rimary amines to nitriles (entry 1, Ta ble 3). [48] It showed ag ood functional group tolerance, and both aromatic and aliphatic amines were oxidizedu nder mild reactionc onditions in the presence of molecular oxygen as the sole oxidant.…”

Section: Nitriles and Iminesmentioning

confidence: 99%

“…Numerous heterogeneous ruthenium systems have also been reported for the production of nitriles and imines . Kaneda et al.…”

Section: Nitriles and Iminesmentioning

confidence: 99%

Ruthenium‐Catalyzed Aerobic Oxidation of Amines

Ray

Hazari

Lahiri

et al. 2018

Amine oxidation is one of the fundamental reactions in organic synthesis as it leads to a variety of value-added products such as oximes, nitriles, imines, and amides among many others. These products comprise the key N-containing building blocks in the modern chemical industry, and such transformations, when achieved in the presence of molecular oxygen without using stoichiometric oxidants, are much preferred as they circumvent the production of unwanted wastes. In parallel, the versatility of ruthenium catalysts in various oxidative transformations is well-documented. Herein, this review focuses on aerobic oxidation of amines specifically by using ruthenium catalysts and highlights the major achievements in this direction and challenges that still need to be addressed.