Cubic nanocasted polyaniline-ordered mesoporous carbon composite and its application for enhanced catalytic activity of palladium nanoparticles in the aerobic oxidation of alcohols in water

From Deep Eutectic Solvents to Nitrogen‐rich Ordered Mesoporous Carbons: A Powerful Host for the Immobilization of Palladium Nanoparticles in the Aerobic Oxidation of Alcohols

“…Our studies showed that in addition to benzyl alcohol, a wide range of both electron rich (such as OCH 3 , CH 3 , and i‐Pr) and electron deficient (such as Cl) derivatives of benzyl alcohol displayed outstanding catalytic performance under such a mild and low catalyst loading and afforded the corresponding carboxylic acids in excellent yields, although, in some rare cases, somewhat higher reaction temperatures and/or larger molar percentages of catalyst were required to obtain excellent results (Table 3, entries 2–8). It is important to note that, benzyl alcohol derivatives bearing sterically demanding substituents at ortho position such as 2‐methoxy, 2‐methyl‐ and 2‐chloro‐ groups are well‐known to react much slower in the oxidation reactions using metal nanoparticles under aerobic conditions than those containing meta and para substituents [8,20,95,96] . To our delight, the substituent positions did not significantly affect the selectivity overall yields of the corresponding carboxylic acids in the present catalyst system (Table 3, entries 9–11).…”

“…It is important to note that, benzyl alcohol derivatives bearing sterically demanding substituents at ortho position such as 2-methoxy, 2-methyl-and 2-chloro-groups are well-known to react much slower in the oxidation reactions using metal nanoparticles under aerobic conditions than those containing meta and para substituents. [8,20,95,96] To our delight, the substituent positions did not significantly affect the selectivity overall yields of the corresponding carboxylic acids in the present catalyst system (Table 3, entries 9-11). It is also worth noting that this catalyst system displayed a high activity for the oxidation of secondary aromatic alcohols such as 1phenylethanol and furnished the corresponding carbonyl products in quantitative yields and high selectivity (Table 3, entries 12).…”

Open Air Direct Oxidative Coupling of Alcohols and Amines to Imines Catalyzed by Ruthenium Nanoclusters Supported on a Mesoporous Carbon (CMK-8) in/on Water

“…These materials have unique features, such as high surface areas, large pore volumes, narrow and well-defined pore size distribution (PSD), and accessible pores with tunable characteristics (i.e., size, shape, and surface functionality), which altogether enable them to provide a versatile matrix for homogeneous and stable dispersion of metal species inside their nanospaces and thus enhance the activity and stability of the resulting supported catalysts in various applications. , Ordered mesoporous carbons (OMCs) are a promising family of porous materials for application as catalyst supports. In addition to the features mentioned above, these materials have excellent chemical, thermal, and mechanical stability. , However, despite the extensive use of porous carbons as support in diverse and important organic transformations and well-documented electrochemical studies, − their utility in the oxidative coupling reaction of alcohols and amines to imines, especially as support for Ru species, is less known and underdeveloped. − Therefore, we aimed to investigate the activity of a novel catalyst system consisting of ruthenium species supported on a three-dimensional (3D) cubic OMC (CMK-8) in the aerobic oxidative coupling of alcohols and amines.…”

Improved catalytic performance by changing surface and textural properties of Ru supported bifunctional periodic mesoporous organosilicas in aerobic oxidation of alcohols

“…During the past decade, numerous metal-based heterogeneous catalysts, such as palladium, 9–19 ruthenium, 20–28 cobalt, 29–37 platinum, 38–45 gold, 46–57 copper, 58–69 vanadium, 70–72 and nickel, 73,74 have successfully been employed in the aerobic oxidation of alcohols to their corresponding carbonyl compounds. Among them, ruthenium-based catalysts, in either homogeneous or heterogeneous form, are the most reliable catalytic systems reported in this research area because of possessing wide range of oxidation states and displaying a high degree of selectivity and efficiency in the oxidation of a variety of structurally diverse alcohols.…”