Graphene Oxide Catalyzed C−H Bond Activation: The Importance of Oxygen Functional Groups for Biaryl Construction

Abstract

A heterogeneous, inexpensive, and environmentally friendly graphene oxide catalytic system for the C-H bond arylation of benzene enables the formation of biaryl compounds in the presence of aryl iodides. The oxygen functional groups in these graphene oxide sheets and the addition of KOtBu are essential for the observed catalytic activity. Reactions with various model compounds and DFT calculations confirmed that these negatively charged oxygen atoms promote the overall transformation by stabilizing and activating K(+) ions, which in turns facilitates the activation of the C-I bond. However, the graphene π system also greatly facilitates the overall reaction as the aromatic coupling partners are easily adsorbed.

A Deoximation Method for Deprotection of Ketones and Aldhydes Using a Graphene‐Oxide‐Based Co‐catalysts System

“…When the amount of NaNO 2 was decreased from 1.5 mol% to 0.5 mol%, there was no major difference in the yield of the desired product ( Table 1, entries [21][22][23]. However, if the amount of NaNO 2 was decreased to 0.2 mol%, 0.1 mol% or 0.05 mol%, the yield of the desired product decreased [24][25][26]. Hence, 0.5 mol% was an optimal quantity of NaNO 2 for this reaction.…”

“…Graphene is a single atomic plane of graphite, constructed with sp 2 -hybridized carbon atoms in a perfect hexagonal lattice. [18] Recently, graphene oxides (GOs) have been developed as catalysts in the Friedel-Crafts acylation of active aromatic compounds, [19] Friedel-Crafts addition reaction of indoles to α,βunsaturated ketones and nitrostyrenes, [20] aza-Michael addition of amines and electrondeficient olefins, [21] Michael addition reactions, [22] direct alkylation reaction between styrenes and alcohols, [23] direct alkylation reaction between iodobenzene and benzene, [24] oxidization reaction of benzene to phenol, [25] oxidation of tetralin to tetralol and tetralone, [26] oxidation of cyclohexane to cyclohexanol, cyclohexanone, and adipic acid, [27] ring-opening reactions, [28] dehydrogen-ation of nitrogen heterocycles, [29] direct iodination of arenes and ketones, [30] trifluoromethylation of arenes, [31] and other reaciotns. [32][33][34] In this work, we report a highly efficient, easily recyclable and simple method for deoximation with good yields under mild conditions using a co-catalysts system composed of graphene oxide (GO) prepared by Hummers' method, [35] sodium nitrite (NaNO 2 ) and air.…”

Graphene‐Oxide‐Catalyzed Cross‐Dehydrogenative Coupling of Oxindoles with Arenes and Thiophenols

“…Graphene oxide (GO)‐based materials have emerged as promising catalyts for liquid‐phase organic reactions owing to their low‐cost, production scalability (thousand tons‐scale production) and rich chemical properties . Endowed with rich oxygen functionalities and aromatic carbon scaffolds GO shows remarkable ability to catalyse a series of synthetic transformations, such as stoichiometric oxidations,– solid acids‐mediated reactions– and oxidations,– C−C couplings– etc. The latter is currently a very active research area and the reactions are usually catalysed by precious metals.…”

Basicity‐Engineered Graphite Fluoride Functionalization and Beyond: An Unusual Reaction between Ultraweak Nucleophile and Ultrastrong CF Bonds

“…Rational chemical functionalizations of graphene provide enormous opportunities for many applications, such as promising and practical energy conversion and storage, photo‐/electro‐/organo‐catalysis, smart and wearable micro/nanoelectronics, cancer diagnosis and therapy, and drinkable water generation . For graphene functionalization community, the most commonly executed strategy is based on GO chemistry since it carries multiple active oxygenous functionalities (e.g., COOH, OH, epoxy, CO) that can be efficiently derivatized .…”