Coupling Of Arylboronic Acids Research Articles

ChemInform Abstract: An Efficient Diamine×Copper Complex Catalyzed Coupling of Arylboronic Acids with Imidazoles.

[formula: see text] A novel diamine.copper complex-catalyzed intermolecular coupling of arylboronic acids (1) with imidazoles (3) is described. In the presence of a catalytic amount of [Cu(OH).TMEDA]2Cl2 (2), arylboronic acids (1) react smoothly with imidazoles (3) in dichloromethane at room temperature to give a variety of N-arylimidazoles (4) in good to excellent yields.

Insights into the Role of New Palladium Pincer Complexes as Robust and Recyclable Precatalysts for Suzuki–Miyaura Couplings in Neat Water

AbstractSuzuki–Miyaura biaryl and diarylmethane syntheses via the coupling of arylboronic acids with aryl and arylmethyl bromides are performed in water by means of two new CNC‐type palladium pincer complexes. Good to excellent results (including high TON values and extended recycling procedures) are obtained in most cases for a range of electronically dissimilar halides and boronic acids. On the basis of a series of kinetics studies, transmission electron microscopy (TEM), mercury drop tests, and quantitative poisoning experiments, the real role of the latter palladacycles, closely linked to the formation and active participation of palladium nanoparticles, is discussed.

ChemInform Abstract: Synthesis and Applications of a New Palladacycle as a High Active Catalyst in the Suzuki Couplings.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Synthesis and applications of a new palladacycle as a high active catalyst in the Suzuki couplings

The reaction of biphenyl-based phosphine P( o-C 6H 4Me)Ph 2 ( 1) with Pd(OAc) 2 in toluene affords the air and water stable palladacycle ( 2) as a binuclear compound which has been characterized by multi-nuclear NMR spectroscopy and elemental analysis as a mixture of cis and trans isomers with relative intensity of 1:3, respectively. This palladacycle is a highly efficient catalyst precursor for the coupling of aryl boronic acids and aryl halides. Both activated and deactivated aryl bromides and chlorides are efficiently coupled in the presence of 2 to furnish the corresponding cross-coupled products in excellent yields, and a wide variety of functional groups are tolerated in aryl halides. This methodology has also been extended for the coupling of bromoarylphosphines and bromoarylphosphine oxides with aryl boronic acids for the generation of hindered corresponding products.

Oxygen- and Base-Free Oxidative Coupling of Arylboronic Acids with Olefins

Oxygen- and Base-Free Oxidative Coupling of Arylboronic Acids with Olefins

Palladium/tetraphosphine catalyzed suzuki cross‐coupling of heteroarylboronic acids with aryl halides

Abstractmagnified imagecis,cis,cis‐1,2,3,4‐Tetrakis(diphenylphosphinomethyl)cyclopentane/[PdCl(C3H5)]2 efficiently catalyses the Suzuki reaction of heteroarylboronic acids with aryl bromides and also the coupling of arylboronic acids with heteroaryl bromides. The coupling of thiophene‐ or benzothiopheneboronic acids, furan‐ or benzofuranboronic acids and 3‐pyridineboronic acid with a variety of aryl bromides gave the corresponding coupling products in good yields. However, in most cases, better results in terms of ratio substrate/catalyst were obtained for the reverse reaction using heteroaryl bromides with arylboronic acids.

Guanidine/Pd(OAc)2‐Catalyzed Room Temperature Suzuki Cross‐Coupling Reaction in Aqueous Media under Aerobic Conditions

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF.

Guanidine/Pd(OAc)2-Catalyzed Room Temperature Suzuki Cross-Coupling Reaction in Aqueous Media under Aerobic Conditions

A highly efficient Pd(OAc)2/guanidine aqueous system for the room temperature Suzuki cross-coupling reaction has been developed. The new water-soluble and air-stable catalyst Pd(OAc)2.(1f)2 from Pd(OAc)2 and 1,1,3,3-tetramethyl-2-n-butylguanidine (1f) was synthesized and characterized by X-ray crystallography. In the presence of Pd(OAc)2.(1f)2, coupling of arylboronic acids with a wide range of aryl halides, including aryl iodides, aryl bromides, even activated aryl chlorides, was carried out smoothly in aqueous solvent to afford the cross-coupling products in good to excellent yields and high turnover numbers (TONs) (TONs up to 850,000 for the reaction of 1-iodo-4-nitrobenzene and phenylboronic acid). Furthermore, this mild protocol could tolerate a broad range of functional groups.

Palladium‐Catalyzed Buchwald–Hartwig Coupling of Deactivated Aminothiophenes with Substituted Halopyridines

AbstractThe palladium‐catalyzed Buchwald–Hartwig coupling of several deactivated aminothiophenecarboxylates with differently substituted halopyridines has been performed for the first time by using Pd(OAc)2, Xantphos as the ligand, and Cs2CO3 as the base. When 2,6‐dihalopyridines were used, the proportion of diaminated product increases with the reactivity of the halopyridines (iodo > bromo > chloro). A bromo monoaminated pyridine derivative, obtained by Buchwald–Hartwig coupling, was further used in the Suzuki coupling of aryl boronic acids bearing electron‐withdrawing or electron‐donating groups. These latter compounds are very interesting as they possess diheteroarylamine and heteroaryl–aryl skeletons including pyridine and thiophene moieties.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

A mixed NCP pincer palladacycle as catalyst precursor for the coupling of aryl halides with aryl boronic acids

The reaction of phosphinite Me 2NCH 2C C(CH 2) 2OP( i-Pr) 2 ( 2) with Li 2PdCl 4 in methanol at room temperature affords the air and water stable mixed pincer palladacycle (Me 2NCH 2(Cl)C C(CH 2) 2OP( i-Pr) 2-κNκCκP)PdCl ( 3) whose structure has been ascertained by means of an X-ray diffraction study. This pincer palladacycle is a highly efficient catalyst precursor for the coupling of aryl boronic acids and aryl chlorides. Both electron-rich and -poor aryl chlorides are efficiently coupled in the presence of 3 to furnish the corresponding cross-coupled products in excellent yields, and a wide variety of functional groups are tolerated in both aryl chloride and aryl boronic acid. The experimental protocol has also been extended for the coupling of iodo and bromo arenes with aryl boronic acids for the generation of hindered biphenyls. The coupling process afforded very good yields of biphenyl products containing two ortho substituents. Steric hindrance is more sensitive for ortho substituents in the aryl boronic acid and is more pronounced when the coupling reaction involves three ortho substituents.

Suzuki Coupling Reactions of Heteroarylboronic Acids with Aryl Halides and Arylboronic Acids with Heteroaryl Bromides Using a Tetraphosphine/Palladium Catalyst.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Site-Specific Catalysis

CHEMISTRY Chemical patterning of surfaces has traditionally been achieved by zapping a reactive coating with light or electron beams. More recently, “dip pen” techniques have used atomic force microscope (AFM) probes to plant molecules in selected surface locations. Davis et al. show that AFM probes can also be used as spatially selective catalysts. They capped the silicon nitride probe tips with palladium nano-particles, which catalyzed the Suzuki coupling of aryl boronic acids to a layer of aryl bromides that were bound through sulfide linkages to a gold surface. After submerging the film in a methanol solution of the boronic acid and a base, they maneuvered the probe to the desired reaction site and induced coupling by applying 20 to 25 nN of force between tip and surface. Reducing the force to the 1- to 5-nN range allowed imaging of the patterned surface without further catalysis. For verification of spatial selectivity, coupling was performed with amine-substituted boronic acid substrates, which were subsequently labeled with fluorescent dye. — JSY J. Am. Chem. Soc. 10.1021/ja043235+ (2005).

Suzuki Coupling Reactions of Heteroarylboronic Acids with Aryl Halides and Arylboronic Acids with Heteroaryl Bromides Using a Tetraphosphine/Palladium Catalyst

cis,cis,cis-1,2,3,4-Tetrakis(diphenylphosphinomethyl)cyclopentane/[PdCl(C 3 H 5 )] 2 efficiently catalyses the Suzuki reaction of heteroarylboronic acids with aryl bromides and also the coupling of arylboronic acids with heteroaryl bromides. The coupling of thiopheneboronic acids. 3-furanboronic acid and 3-pyridineboronic acid with a variety of aryl bromides gave the corresponding adducts in good yields. However, in most cases, better results in terms of substrate/catalyst ratio were obtained for the reaction of heteroaryl bromides with arylboronic acids.

Unsymmetrical Diaryl Sulfones Through Palladium‐Catalyzed Coupling of Aryl Boronic Acids and Arylsulfonyl Chlorides.

AbstractFor Abstract see ChemInform Abstract in Full Text.

Base-free anaerobic Cu(II) catalysed aryl-nitrogen bond formations

The coupling of arylboronic acids with imidazole in the presence of binuclear bis-μ-hydroxy copper(II) complexes is reported. The reactions can be performed in air as well as under nitrogen atmosphere. Reactions are carried out at ambient temperature without the need for base. The presence of water is essential for the reaction to proceed. Ligand effects on the yield and selectivity are reported.

A Simple Copper Salt Catalyzed N‐Arylation of Amines, Amides, Imides, and Sulfonamides with Arylboronic Acids.

A simple copper salt catalyzed N-arylation reaction with arylboronic acids is reported. In the presence of a catalytic amount of a simple copper salt, the coupling of arylboronic acids with imides was performed in MeOH to give N-arylimides in excellent yields: a variety of amines, amides and sulfonamides could also be successfully coupled with arylboronic acids to give cot-responding N-arylated products in moderate yields.

Unsymmetrical diaryl sulfones through palladium-catalyzed coupling of aryl boronic acids and arylsulfonyl chlorides.

[reaction: see text] A simple and efficient method for the synthesis of unsymmetrical diaryl sulfones using the palladium-catalyzed coupling of aryl boronic acids and arylsulfonyl chlorides has been developed. High product yields, a short reaction time, and mild reaction conditions are important features of this method.

A Superior Non‐Symmetrical NCP Pincer Type Palladacycle Catalyst Precursor for the Coupling of Aryl Boronic Acids with Aryl Chlorides.

AbstractFor Abstract see ChemInform Abstract in Full Text.

A Simple Copper Salt Catalyzed N-Arylation of Amines, Amides, Imides, and Sulfonamides with Arylboronic Acids

A simple copper salt catalyzed N-arylation reaction with arylboronic acids is reported. In the presence of a catalytic amount of a simple copper salt, the coupling of arylboronic acids with imides was performed in MeOH to give N-arylimides in excellent yields; a variety of amines, amides and sulfonamides could also be successfully coupled with arylboronic acids to give corresponding N-arylated products in moderate yields.

Coupling of Aryl Halides with Aryl Boronic Acids with P(C6H5)(2‐C6H4Cl)2 as the Supporting Ligand.

AbstractFor Abstract see ChemInform Abstract in Full Text.