Oxidative Coupling Of 2-naphthols Research Articles

Smart Hydrogel Reactor of Poly(N-isopropylacrylamide)/Polyethylene Glycol Interpenetrating Polymer Networks for Oxidative Coupling of 2-Naphthol

AbstractHydrogels with an interpenetrating polymer network (IPN) structure composed of poly(N-isopropylacrylamide) (poly-NIPAM) gel and a gel containing polyethylene glycol (PEG) chains were synthesized. They showed a typical temperature-responsive volume change in water owing to the constructed poly-NIPAM gel component. Oxidative coupling of 2-naphthol with IPN cryogels and a conventional catalyst, the CuCl2 complex of N,N,N′,N′-tetramethylenediamine, was conducted in water under an O2 atmosphere; the IPN gel prepared from PEG with a larger molecular weight of 11000 afforded a product with a good yield of 73% (91% conv.) during the reaction in basic media. The hydrogel effectively promoted the reaction but hardly produced any product without the catalyst, acting as a reactor vessel in the water. Owing to the low durability of the PEG gel component for hydrolysis, a limitation was also suggested during experiments on the recyclability of the hydrogel.

Accurate Understanding the Catalytic Role of MnO2 in the Oxidative-Coupling of 2-naphthols into 1,1′-bi-2-naphthols

It has been reported that β-MnO2 has photocatalytic activity for the oxidative-coupling of 2-naphthols into 1,1′-bi-2-naphthols. Nevertheless, it is hard to exclude the possibility that the oxidative-coupling of 2-naphthols is initiated by β-MnO2 catalysis in dark due to the insufficient investigations in the related reports. In the present work, the oxidative-coupling of 2-naphthols into 1,1′-bi-2-naphthols with different phases MnO2 catalysis in dark and under visible-light irradiation were systematically investigated. The results revealed that the oxidative-coupling of 2-naphthols is jointly initiated by MnO2 catalysis and O2-oxidation, not by MnO2 photocatalysis. Among the α-MnO2, β-MnO2, γ-MnO2 and δ-MnO2 catalysis, β-MnO2 catalysis has the optimal performance, its selectivity for the oxidative-coupling of 2-naphthols into 1,1′-bi-2-naphthols is close to 100%, and its catalytic capacity could be well retained after multiple using. Our findings provide comprehensive and accurate understanding the catalytic role of MnO2 for the oxidative-coupling of 2-naphthols into 1,1′-bi-2-naphthols. In the present work, the oxidative-coupling of 2-naphthols into 1,1′-bi-2-naphthols was proved to be jointly initiated by MnO2 catalysis and O2-oxidation, not by MnO2 photocatalysis. β-MnO2 has the optimal catalytic activity for the oxidative-coupling of 2-naphthols relative to α-MnO2, γ-MnO2 and δ-MnO2.

Pd–Au–Y as Efficient Catalyst for C–C Coupling Reactions, Benzylic C–H Bond Activation, and Oxidation of Ethanol for Synthesis of Cinnamaldehydes

Pd–Au nanoalloy supported on zeolite-Y (Pd–Au–Y) matrix was found to be an effective catalyst for C–Cl bond activation and oxidative coupling of 2-naphthol, leading to the formation of various biar...

Oxidative Coupling of 2-Naphthols on Graphene Oxide

Oxidative Coupling of 2-Naphthols on Graphene Oxide

Enantioselective Oxidative Coupling of 2-Naphthols and Aryl Methyl Ketones

Enantioselective Oxidative Coupling of 2-Naphthols and Aryl Methyl Ketones

Oxidative coupling of 2-naphthol to (R)/(S)-BINOL by MCM-41 supported Mn-chiral Schiff base complexes

Conversion of 2-naphthol toC2-symmetric BINOL is achieved in 91% ee in the presence of an Mn-Schiff base chiral catalyst supported on MCM-41.

Oxidative coupling of 2-naphthol by zeolite-Y supported homo and heterometallic trinuclear acetate clusters

Trinuclear metal-oxo cluster supported on zeolite-Y is found to be efficient catalyst for oxidation of 2-naphthol to BINOL with high turn over frequency.

Catalytic activity of choline modified Fe(III) montmorillonite

A series of mixed-cation organoclays, containing both Fe 3+ and choline + cations, were prepared using montmorillonite and tested for catalytic activity in three Fe 3+-mediated reactions: the oxidative coupling of 2-naphthol, coupling of anthrone and a Lewis-acid catalysed indole conjugate addition. Clays with different Fe 3+:choline + ratios were required to achieve maximum catalytic activity in each reaction. For coupling of both 2-naphthol and anthrone, the most effective catalysts, as measured by the turnover frequency (TOF), were mixed Fe 3+/choline + clays of varying ratios, but the catalytic efficiency of Fe 3+ montmorillonite in the conjugate addition of indole with methyl vinyl ketone decreased with the addition of choline +. This result could potentially be explained by the effect of choline + decreasing the accessibility of Lewis acid domains. The results of this study provide proof that it is possible to tune mixed-cation clays with maximum catalytic activity in specific reaction types for specific substrates. Such mixed-cation organoclays offer advantages over traditional clay-based sorbents in environmental remediation applications, as they have the potential to bind organic contaminants selectively, via interaction with surface-exchanged organic cations, and neutralise organic molecules through catalytic exchange cations that are also present on the clay surface.

Ytterbium triflate-assisted catalytic oxidative cross-coupling of 2-naphthol derivatives

The oxidative coupling of 2-naphthol and 3-hydroxy-2-naphthoate derivatives with a copper catalyst under an O 2 atmosphere was carried out. The reaction in the presence of a catalytic amount of the Lewis acid, Yb(OTf) 3, proceeded in a cross-coupling specific manner.

Oxidative cross-coupling leading to 3-amido substituted 1,1′-bi-2-naphthol derivatives

The oxidative coupling of 2-naphthol and 3-hydroxy-2-naphthamide with various copper catalysts under an O 2 atmosphere was performed. The reaction proceeded in a cross-coupling specific manner when the substrate has a secondary amido group.

Copper-alginates: a biopolymer supported Cu(II) catalyst for 1,3-dipolar cycloaddition of alkynes with azides and oxidative coupling of 2-naphthols and phenols in water

Copper(II) ions immobilized onto a biopolymer (sodium alginate) is an effective heterogeneous catalyst for 1,3-dipolar cycloaddition of alkynes with azides and oxidative coupling of 2-naphthols and phenols in water to afford the 1,4-disubstituted 1,2,3-triazoles and biaryl compounds respectively in good yields. The catalyst was recovered quantitatively by simple filtration and reused for several times without significant loss of activity.

Synthesis and Resolution of the Atropisomeric 1,1'-Bi-2-naphthol: An Experiment in Organic Synthesis and 2-D NMR Spectroscopy

The synthesis and resolution of the atropisomeric 1,1'-bi-2-naphthol illustrates several important concepts in organic chemistry and serves as a good experiment for organic chemistry laboratory course of intermediate to advanced levels. Racemic 1,1'-bi-2-naphthol is synthesized by the oxidative coupling of 2-naphthol and is resolved into the enantiopure form by the selective inclusion compound formation of the R enantiomer with (−)-N-benzylcinchonidinium chloride. The enantiomeric excess of the products are determined by chiral HPLC. The naphthol unit of 1,1'-bi-2-naphthol is composed of a benzene and a phenol fused together. Both 1H and 13C NMR spectra show complicated and overlapping signals in the aromatic region and complete signal assignment is extremely difficult. Unambiguous signal assignment is made possible with the help of various 2-D NMR techniques such as COSY, HMQC, and COLOC. It serves as an advanced exercise for spectroscopic structural identification of organic compounds.

A straightforward synthesis in aqueous medium of enantiomerically. Enriched S(-)2,2'-dihydroxy-1,1'-binaphthyl.

Chiral, atropisomeric 2,2'-dihydroxy-1,1'-binaphthyl has been extensively used to direct asymmetric processes. Its key role in asymmetric catalysis has spurred efforts to synthesize it in the optically pure form, but the reported synthetic routes have a significant environmental impact. In an aqueous peroxydase-cyclodextrin system the oxidative coupling of 2-naphthol took place very rapidly in almost quantitative yield and resulted in an enantiomeric excess. This one-pot synthesis do not require any organic solvents and oxidising metal cations.

Efficient Solvent-Free Oxidative coupling of 2-Naphthols by Copper(Ii) Oxymetasilicate under Microwave Irradiation

Solvent-free oxidative coupling of 2-naphthols by copper(II) oxymetasilicate without solvent under microwave irradiation gives the corresponding 1,1′-binaphthalene–2,2′-diols in 75-97% yields.

MICROWAVE-ASSISTED EFFICIENT OXIDATIVE COUPLING OF 2-NAPHTHOLS IN THE SOLID STATE

ABSTRACT Microwave-assisted oxidative coupling of 2-naphthols at solid state gave the corresponding coupling products in high yields, which provides a simple, rapid and efficient approach to the preparation of binaphthols.

Oxidative coupling of 2-naphthols catalysed by clays-supported iron catalysts

Iron pillared clays (Fe-PILC) were compared to Fe-exchanged K10 (Fe-K10) for the oxidative coupling of 2-naphthols to the corresponding binaphthols. Fe-K10 appeared as the most efficient heterogeneous catalyst giving nearly quantitative yields with many naphthols. The highest activity displayed by Fe-K10 is attributed to the easier accessibility of catalytic sites of the clay. The catalyst can be recycled several times with success.