Cobalt Schiff Base Immobilized on a Graphene Nanosheet with N, O Linkage for Cross-Coupling Reaction

Abstract

A simple and direct pathway to synthesize heterogeneous catalyst by covalently immobilizing a cobalt Schiff base complex on the surface of amino functionalized graphene oxide for the cross coupling of aryl halides and arylboronic acids is reported. The as synthesized samples were characterized using various spectroscopic techniques and thermal analysis to attain their structural and functional features. The analysis confirmed that the Co bounded to the ligand using bi­(N, O) linkage and the Co Schiff base complex immobilized onto the functionalized graphene oxide through its amino moiety. The catalytic investigation confirmed the product yield up to 96.5% for the Suzuki cross coupling using gas chromatography. ICP analysis shows that the central active metal is 85% in its catalyst even after the fifth iteration. High product yield, environmentally benign, easy workup, easy filtration of catalyst, and mild reaction conditions are the main facets of this catalyst.

Fabrication of a recyclable magnetic halloysite-based cobalt nanocatalyst for the efficient degradation of bisphenol A and malachite green

“…Moreover, on moving to the high resolution XPS spectrum of N 1s, peak positioned at 399.63 eV corresponds well with the C=N bond, affirming the successful immobilization of ligand through Schiff base condensation. 60 A detailed analysis of high-resolution XPS spectrum of Fe 2p divulged two characteristic peaks at 709.63 eV (Fe 2p 3/2 ) and 723.34 eV (Fe 2p 1/2 ) which validated that iron is present in its +2 oxidation state. Moreover, peaks at 711.35 (Fe 2p 3/2 ) and 724.57 eV (Fe 2p 1/2 ) are in well accordance with trivalent state of iron, affirming the successful decoration of Fe 3 O 4 NPs on HNTs surface.…”

Pd/Co3O4–Pd/PdO formed in situ on the surface of the self-assembly ferrocenylimine Pd(ii)/Co(ii) monolayer for catalyzing the Suzuki cross-coupling reaction—formation, synergistic effect, and catalytic mechanism

“…[46][47][48] The surface structure of the catalyst is also an important factor affecting the activity, 49 which can be endowed by modifying the surface of the catalyst, which can be modified by self-assembly (SAM), and the regular film surface can be fabricated as a platform, [50][51][52][53][54][55][56] on which the changes of active sites can be easily detected and the real active centre and function may be elucidated. [57][58][59][60][61][62] Previous studies on ligands, the molecular structure of the surface, metal combination, and carrier with the synergy between metals to develop the higher active catalysts have been our effort directions. 14,[60][61][62][63][64][65][66][67][68][69][70][71][72][73][74][75][76][77][78][79] In this study, a ferrocenylimine Pd/Co film supported by GO was prepared using SAM.…”

Hydrophilic Pd/MgO Nanosystem for the Highly Efficient Aqueous-Phase Catalysis of Suzuki–Miyaura Reactions

“…Palladium-catalyzed Suzuki coupling reaction has become one of the most effective and important methods for making C–C bonds since the first report in 1979. − The coupling reaction of aryl halides with organoboron reagents that features extensive substrate applicability and functional group tolerance has been widely applied in the synthesis of versatile natural products, pharmaceuticals, and functional materials. − Currently, homogeneous palladium-based catalysts, such as palladium salts with phosphine ligands or N -heterocyclic carbene ligands, have still been the most widely used catalysts, and products with desirable yields and efficiencies have been achieved. − Nevertheless, they suffer from intrinsic deficiency in product separation and catalyst recycling, which significantly restricted their large-scale industrial application. Besides, most Suzuki coupling reactions have been currently performed in large amounts of organic solvents ( N , N -dimethylformamide (DMF), tetrahydrofuran (THF), 1,4-dixoane, and so forth), which are toxic and harmful to the environment. − Therefore, out of academic and industrial research, a heterogeneous supported palladium catalyst that exhibits high catalytic activities and is easy to recycle when operated in green solvents, particularly in water, to realize green and efficient synthesis is urgently needed.…”