Coupling Reaction Of Arylboronic Acids Research Articles

A base-free Chan–Lam reaction catalyzed by an easily assembled Cu(II)-carboxylate metal-organic framework

A new copper(II) metal-organic framework is constructed as a sustainable copper heterogeneous catalyst. Cu-DPTCA, with high catalytic activity, can effectively promote the Chan–Lam coupling reaction of arylboronic acids and amines without adding any base or additive.

Cu(OAc)2‐porphyrins as an efficient catalytic system for base‐free, nature mimicking Chan–Lam coupling in water

The use of porphyrins as ligands in organic synthesis reveals the natural process, because these are the constituent motifs of catalysts in many bio‐organic reactions. This article presents the synthesis of two N‐pincer tetradentate porphyrins; tetrasodium meso‐tetra(p‐sulfonatophenyl)phorphyrin (H2TSTpSPP) and meso‐tetra(m‐carboxyphenyl)porphyrin (H2TmCPP), and study on their aptness for Cu‐catalyzed C–N coupling reactions of arylboronic acids and amines (Chan–Lam coupling reaction) in water under external base free conditions. The porphyrins and Chan–Lam coupling products were well characterized by their spectral analysis. The high product yields, application of nature‐inspired conditions, large extent of substrates, ease of making and handling the ligands, avoidance of base, and use of water as reaction media are the attractive attributes of this finding.

Synthesis of Benzo[b]thiophenes through Rhodium‐Catalyzed Three‐Component Reaction using Elemental Sulfur

AbstractA benzo[b]thiophene synthesis by Rh‐catalyzed three‐component coupling reaction of arylboronic acids, alkynes, and elemental sulfur (S8) is developed. A notable feature of this protocol is that the thienannulation (thiophene annulation) proceeds with high regioselectivity via the sequential alkyne insertion, C−H activation, and then sulfur atom transfer to the metallacycle intermediate. In a similar manner, dibenzothiophenes can be synthesized from the parent biarylboronic acids and S8.magnified image

Oxidative Coupling Reactions of Arylboronic Acids and Fluoroform-Derived AgCF3

Oxidative Coupling Reactions of Arylboronic Acids and Fluoroform-Derived AgCF₃

Review of large-pore mesostructured cellular foam (MCF) silica and its applications

AbstractThe unique properties of mesostructured cellular foam (MCF) silica such as, large pore size, continuous three-dimensional (3D) pore system and hydrothermal robust materialallow favorable conditions for incorporating active sites to produce modified MCF silica as catalysts, biocatalysts and adsorbents. Recently, the modified MCF silicas were reported to be efficient catalysts for the hydrogenation of phenylacetylene, heck coupling reaction of arylboronic acid, etc. Biocatalysts derived from modified MCF silicas were found to be a potential to convert glucose to gluconic acid, hydrolysis of N-benzoyl-DLarginine-p-nitroanilide (BAPNA) and casein, transesterification of racemic 1 phenyl- ethanol and hydrolytic, etc. Several separation processes such as CO2 capture and adsorption of L-tryptophan, lysozyme and bovine serum were sucessfully conducted using adsorbents derived from modified MCF silicas. This paper reviews the synthesis of the MCF silica material and the incorporation of active sites or immobilization of enzymes in the MCF silica material. Additionally, a detailed understanding of the characterization of the modified MCF silicas, which includes pore size, active sites/enzymes sizes, amount of active sites/enzymes bound with the MCF silica, was also discussed to obtain their potentialities as catalysts, biocatalysts and adsorbents. The review also describes recent progress on the applications of the MCF silica.

Nano CoCuFe2O4‐catalyzed coupling reaction of arylboronic acid with amines and thiols: An atom‐economic and ligand‐free route to access unsymmetrical amines and sulfides

An efficient protocol was developed for the nano CoCuFe2O4‐catalyzed C‐N and C‐S bond formation. By this catalytic system, both amine and sulfide‐based structural motifs were formed efficiently in aryl halide‐free route. The amination reaction of phenyl boronic acid with various types of amines was conducted under ligand‐free conditions, in ethanol as a green solvent at 60°C. Unsymmetrical diaryl/aryl alkyl sulfide synthesis via the coupling reaction of arylboronic acids with thiols was also conducted. The nano cobalt‐copper ferrite was used as a heterogenous efficient, inexpensive, magnetically separable and recyclable catalyst that can be used for several cycles.

N,O-Bidentate ligand-tunable copper(ii) complexes as a catalyst for Chan-Lam coupling reactions of arylboronic acids with 1H-imidazole derivatives.

An efficient procedure for Chan-Lam coupling reactions of arylboronic acids with 1H-imidazole derivatives using N,O-bidentate ligand-tunable copper(ii) complexes as a catalyst under base-free conditions has been developed. This protocol features mild reaction conditions, high yields and compatibility with different functional groups, providing a direct and facile strategy for the construction of C-N bonds and synthesis of heterocyclic compounds.

Efficient in situ N-heterocyclic carbene palladium(ii) generated from Pd(OAc)2 catalysts for carbonylative Suzuki coupling reactions of arylboronic acids with 2-bromopyridine under inert conditions leading to unsymmetrical arylpyridine ketones: synthesis, characterization and cytotoxic activities.

N,N-Substituted benzimidazole salts were successfully synthesized and characterized by 1H-NMR, 13C {1H} NMR and IR techniques, which support the proposed structures. Catalysts generated in situ were efficiently used for the carbonylative cross-coupling reaction of 2 bromopyridine with various boronic acids. The reaction was carried out in THF at 110 °C in the presence of K2CO3 under inert conditions and yields unsymmetrical arylpyridine ketones. All N,N-substituted benzimidazole salts 2a–i and 4a–i studied in this work were screened for their cytotoxic activities against human cancer cell lines such us MDA-MB-231, MCF-7 and T47D. The N,N-substituted benzimidazoles 2e and 2f exhibited the most cytotoxic effect with promising cytotoxic activity with IC50 values of 4.45 μg mL−1 against MDA-MB-231 and 4.85 μg mL−1 against MCF7 respectively.

Copper immobilized at a covalent organic framework: an efficient and recyclable heterogeneous catalyst for the Chan–Lam coupling reaction of aryl boronic acids and amines

A covalent organic framework immobilized Cu catalyst was prepared and applied for synthesis of N-arylated products by Chan–Lam coupling reaction of arylboronic acids with various amines.

L-Arginine as a base and ligand for the palladium-catalyzed C-C and C-N cross-coupling reactions in aqueous media

l-Arginine (2-amino-5-guanidinopentanoic acid) acts as a base and ligand in reaction medium, exhibits a very high activity and recyclability to palladium-catalyzed C-C and C-N cross-coupling reactions in aqueous media. The corresponding Suzuki products were obtained in good to excellent yields by using various aryl halides (I, Br, Cl). Also, the cross coupling reactions of arylboronic acids with various amines in aqueous medium proceed in good to excellent yield under same conditions. Furthermore, the catalyst could be easily separated from the reaction mixture and could be recycled several times without significant loss in its catalytic activity.

A copper-catalyzed oxidative coupling reaction of arylboronic acids, amines and carbon dioxide using molecular oxygen as the oxidant

A Cu-catalyzed oxidative coupling reaction of arylboronic acids, amines and carbon dioxide is described, providing a route to O-aryl carbamates.

Coupling of arylboronic acids with benzyl halides or mesylates without adding transition metal catalysts

We report herein a transition-metal-free coupling reaction of arylboronic acids with benzyl halides and mesylates for the construction of C(sp2)C(sp3) bonds. A unique feature of this coupling reaction is the formation regioisomers in some cases. Mechanistic studies suggest that this reaction may proceed via an unprecedented Friedel–Crafts-type reaction pathway under base conditions with the assistance of boronic acid moiety.

Metal-Free, DTBP-Mediated Methylthiolation of Arylboronic Acids with Dimethyldisulfide

An efficient method for the C–S bond formation via the coupling reaction of arylboronic acids with dimethyldisulfide has been developed under the metal-free conditions. This novel protocol provides an attractive route for the synthesis of aryl methyl sulfides, due to its operational simplicity, satisfactory yields, excellent functional-group tolerance, as well as the mild reaction conditions.

An Abnormal N‐Heterocyclic Carbene‐Based Palladium Dimer: Aqueous Oxidative Heck Coupling Under Ambient Temperature

AbstractHerein we report the synthesis of a new abnormal N‐heterocyclic carbene (aNHC)‐based ligand and its use in synthesizing an acetate bridged CH activated palladium dimer (1). In complex 1, the carbene ligand displays an abnormal mode of binding with the palladium(II) ion. We used complex 1 as a catalyst for the oxidative Heck coupling reaction of arylboronic acids with electron‐deficient as well as electron‐rich olefins at ambient temperature in water to produce selectively the β‐arylated products in good to excellent yields.magnified image

ChemInform Abstract: Versatile Palladium(II)‐Catalyzed Suzuki—Miyaura Coupling in Ethanol with a Novel, Stabilizing Ligand.

Abstract Suzuki–Miyaura coupling reactions of arylboronic acids with aryl bromides were mediated by PdCl2 and bdppmapy (N,N-bis-(diphenylphosphanylmethyl)-2-aminopyridine) that both stabilizes and solubilizes the catalyst in predominantly ethanol as a solvent. Excellent yields for a wide variety of substrates were obtained under relatively mild conditions in this ‘green’ solvent.

A highly active palladium(II)–bis(oxazoline) catalyst for Suzuki–Miyaura, Mizoroki–Heck and sonogashira coupling reactions in aqueous dimethylformamide

An efficient catalytic system based on a new palladium–bis(oxazoline) (Pd-BOX-1) complex has been developed. The complex Pd-BOX-1 adopts a legless chair‐type structure where the distorted square planar [PdN2Cl2] moiety and the benzene ring spacer represent the seat and the chair back, respectively. The catalytic activity of Pd-BOX-1 has been investigated in dimethylformamide–water under aerobic and mild conditions in Suzuki–Miyaura coupling reactions of arylboronic acids with aryl iodides, aryl bromides and aryl chlorides, Mizoroki–Heck coupling reactions of aryl halides with styrene derivatives, and Sonogashira coupling reactions of aryl halides with terminal alkynes. A wide range of functional groups as substituents on the arylboronic acids and aryl halides were considered. Pd-BOX-1 demonstrates exceptional air and moisture stability. Of note, the catalyst system based on Pd-BOX-1 shows high recycling ability in Suzuki–Miyaura coupling reactions in dimethylformamide–water without any loss in catalytic activity. Copyright © 2015 John Wiley & Sons, Ltd.

Versatile palladium(II)-catalyzed Suzuki–Miyaura coupling in ethanol with a novel, stabilizing ligand

Suzuki–Miyaura coupling reactions of arylboronic acids with aryl bromides were mediated by PdCl2 and bdppmapy (N,N-bis-(diphenylphosphanylmethyl)-2-aminopyridine) that both stabilizes and solubilizes the catalyst in predominantly ethanol as a solvent. Excellent yields for a wide variety of substrates were obtained under relatively mild conditions in this ‘green’ solvent.

ChemInform Abstract: Solvent‐Free N‐Arylation of Amines with Arylboronic Acids under Ball Milling Conditions.

Solvent-free coupling reactions of arylboronic acids with various amines were presented under ball milling conditions, achieving the aromatic amine coupling products with yields ranging from moderate to good. This type of mechano-chemistry exhibited advantages of solvent-free property, high efficiency, simple work-up procedure and eco-friendliness.

Facile synthesis of Fe@Pd nanowires and their catalytic activity in ligand-free C[sbnd]N bond formation in water

This work reports a facile synthesis of Fe@Pd nanowires. Ligand-free cross coupling reactions of arylboronic acids with various amines in aqueous medium proceed in very good to excellent yield with the use of Fe@Pd nanowires. Furthermore, the catalyst could be easily separated from the reaction mixture using a magnet and could be recycled several times without loss of catalytic activity.

Synthesis of aryloxyazetidine derivatives by CuI/l-proline catalyzed coupling reaction of arylboronic acid with 1-Boc-3-iodoazetidine

A novel CuI/l-proline catalyzed coupling reaction of 1-Boc-3-iodoazetidine with various arylboronic acids which produced aryloxyazetidine derivatives in moderate to good yields was investigated.