Synthesis Of Biaryl Compounds Research Articles

Electrochemical synthesis of biaryls by reductive extrusion from N,N’-diarylureas

The synthesis of biaryl compounds by the transition-metal free coupling of arenes is an important contemporary challenge, aiming to avoid the toxicity and cost profiles associated with the metal catalysts commonly used in the synthesis of these pharmaceutically relevant motifs. In this paper, we describe an electrochemical approach to the synthesis of biaryls in which aniline derivatives are coupled through the formation and reduction of a temporary urea linkage. The conformational alignment of the arenes in the N,N’-diaryl urea intermediates promotes C-C bond formation following single-electron reduction. Our optimized conditions are suitable for the synthesis of a variety of biaryls, including sterically hindered examples carrying ortho-substituents, representing complementary reactivity to most metal catalysed methods.

Microwave‐Assisted Silver‐Catalyzed Synthesis of Biaryl Compounds

AbstractA rapid, ligand/oxidant/base‐free, silver carbonate‐catalyzed homocoupling reaction of aryl boronic acids under microwave irradiation for the synthesis of symmetric biaryls is described here. This protocol tolerates a wide range of electron‐donating, electron‐withdrawing, and heterocyclic boronic acids to provide the corresponding biaryl products in good to excellent yields. The features of this strategy include a wide substrate scope, mild reaction conditions, high functional group tolerance, good to excellent yields, and short reaction time.

Carboxylic acids as double aryl group donors for biaryl synthesis

The synthesis of biaryl compounds by employing carboxylic acids as double aryl group donors is reported.

Phosphorus ligand-free Suzuki–Miyaura reactions in the presence of ABTS at room temperature in water

A catalytic system for a phosphorus ligand-free Suzuki–Miyaura reaction in water at room temperature was disclosed. Ammonium 2,2′-azino-bis(3-ethylbenzthiazoline-6-sulfonate) (ABTS) was an efficient promoter and acted both as a ligand and as a surfactant for the synthesis of biaryl compounds via the Suzuki–Miyaura reaction in water. The targeted biaryl architectures were achieved under mild conditions with high efficiency and good functional group tolerance.

Synthesis of biaryl compounds via Suzuki homocoupling reactions catalyzed by metal organic frameworks encapsulated with palladium nanoparticles

Heterogeneous homocoupling reactions of phenylboronic acids were greatly accelerated via Suzuki homocoupling reactions. In this work, a tandem route was designed which firstly one part of phenylboronic acids reacted with iodine to form iodobenzenes, then another part of phenylboronic acids coupled with iodobenzenes to produce biaryl compounds. The tandem reaction were catalyzed by a bifunctional heterogeneous catalyst of metal organic frameworks encapsulated with palladium nanoparticles (Pd@MOFs). This strategy for forming symmetric C-C bond between benzene rings has obvious advantages such as high efficiency, easy separation, good recyclability and no addition of toxic halogenated benzene.

Easy conversion of nitrogen‐rich silk cocoon biomass to magnetic nitrogen‐doped carbon nanomaterial for supporting of Palladium and its application

In this study, magnetic nitrogen‐doped carbon (MNC) was fabricated through facile carbonization and activation of natural silk cocoons containing nitrogen and then combined with Fe3O4 nanoparticles to create a good support material for palladium. Palladium immobilization on the support resulted in the formation of magnetic nitrogen‐doped carbon‐Pd (MNC‐Pd). The prepared heterogeneous catalyst was well characterized using FT‐IR, TGA, EDX, FE‐SEM, XRD, VSM, and ICP‐OES techniques. Thereafter, the synthesis of biaryl compounds was conducted to investigate the catalyst performance via the reaction of aryl halides and phenylboronic acid. Further, the catalyst could be used and recycled for six consecutive runs without any significant loss in its activity.

Synthesis of Biaryl Compounds in Flow via a Lithiation, Borylation, Suzuki–Miyaura Cross-Coupling Pathway

Key words microreactors - lithiation - borylation - Suzuki–Miyaura coupling

Atroposelective Synthesis of Biaryl Compounds via Palladium-Catalyzed Suzuki–Miyaura Cross-Coupling

Atroposelective Synthesis of Biaryl Compounds via Palladium-Catalyzed Suzuki–Miyaura Cross-Coupling

The fungal gene cluster for biosynthesis of the antibacterial agent viriditoxin

BackgroundViriditoxin is one of the ‘classical’ secondary metabolites produced by fungi and that has antibacterial and other activities; however, the mechanism of its biosynthesis has remained unknown.ResultsHere, a gene cluster (vdt) responsible for viriditoxin synthesis was identified, via a bioinformatics analysis of the genomes of Paecilomyces variotii and Aspergillus viridinutans that both are viriditoxin producers. The function of the eight-membered gene cluster of P. variotii was characterized by targeted gene disruptions, revealing the roles of each gene in the synthesis of this molecule and establishing its biosynthetic pathway, which includes a Baeyer–Villiger monooxygenase catalyzed reaction. Additionally, a predicted catalytically-inactive hydrolase was identified as being required for the stereoselective biosynthesis of (M)-viriditoxin. The subcellular localizations of two proteins (VdtA and VdtG) were determined by fusing these proteins to green fluorescent protein, to establish that at least two intracellular structures are involved in the compartmentalization of the synthesis steps of this metabolite.ConclusionsThe predicted pathway for the synthesis of viriditoxin was established by a combination of genomics, bioinformatics, gene disruption and chemical analysis processes. Hence, this work reveals the basis for the synthesis of an understudied class of fungal secondary metabolites and provides a new model species for understanding the synthesis of biaryl compounds with a chiral axis.

Nanostructured Pyrophosphate Na2PdP2O7‐Catalyzed Suzuki‐Miyaura Cross‐Coupling Under Microwave Irradiation

Nanostructured palladium pyrophosphate (Na2PdP2O7) catalyst was synthesized and well characterized by using different techniques (TGA, XRD, SEM, TEM....). This nanocatalyst exhibited excellent catalytic activity in the synthesis of biaryl compounds via Suzuki‐Miyaura cross‐coupling to produce their corresponding products in good to excellent yields under mild conditions. The catalyst is recyclable and was recycled for four runs for the reaction of 4‐bromoacetophenone with phenylboronic acid without appreciable loss of its catalytic activity.

Production of magnetically recoverable, thermally stable, bio-based catalyst: Remarkable turnover frequency and reusability in Suzuki coupling reaction

In any catalysis system, regeneration of the used catalyst is of great importance to reduce the cost of industrial applications. However, recovery of the used catalyst from the reaction medium is a difficult task and this can hinder regeneration process. Magnetic separation has emerged as an effective tool to overcome the recovery problem. Hence, in this study a magnetically recoverable sporopollenin-based Pd catalyst has been designed and used in synthesis of biaryl compounds via Suzuki coupling reaction. The thermally stable catalyst exhibited excellent catalytic behaviour without giving any by-products. It is noteworthy that despite their low product yield of aryl chlorides in coupling reactions, remarkable product yields which are comparable to those of aryl bromides and iodides were recorded for aryl chlorides. With very low catalyst loading (1×10−3mol%), the catalyst gave TOFs values exceeding one million; i.e., 1.237.500 in very short reaction time. Due to its magnetically separable nature, the catalyst could be recovered from the reaction media easily by increasing the reusability of the catalyst. Even in tenth run biphenyl yield dropped from 99 to 93%.

Gold-catalysed cross-coupling between aryldiazonium salts and arylboronic acids: probing the usefulness of photoredox conditions.

The synthesis of biaryl compounds from aryldiazonium salts and arylboronic acids was achieved using PPh3AuCl as catalyst, CsF as base and acetonitrile as solvent. Combined to photosensitizers, irradiation by blue LEDs allowed accelerating the reaction and expanding its scope. Various functional groups were compatible including bromoaryls, iodoaryls, aldehydes and alcohols. A 2-iodobenzyl alcohol moiety was smoothly introduced by this method, enabling its consecutive isotopic labelling by a Pd-catalysed alkoxycarbonylation.

Carboxymethyl chitosan Schiff base supported heterogeneous palladium(II) catalysts for Suzuki cross-coupling reaction

In this study, two new O-carboxymethyl chitosan Schiff bases supported Pd(II) catalyst were synthesized (OCMCS-3aPd and OCMCS-4aPd). The catalysts were characterized with FTIR, TG/DTG, SEM/EDAX, XRD, ICP-OES, UV–vis, magnetic moment and molar conductivity. The catalytic activities of these catalysts were tested in the synthesis of biaryl compounds by Suzuki cross-coupling reactions. Characterizations of the biaryls were performed with GC–MS and 1H NMR. In synthesis of the biaryl compounds in the presence of the Pd(II) catalyst, high selectivity was observed; no homo-coupling byproducts were detected in the spectra. A reusability test demonstrated that the catalysts were highly efficient even after ten run. The mercury poisoning and leaching tests indicated that the catalysts have heterogeneous nature.

Enantioselective Synthesis of Biaryl Compounds via Suzuki–Miyaura Cross-Coupling Using a Palladium Complex of 7′-Butoxy-7-(diphenylphosphino)-8,8′-biquinolyl: Investigation of a New Chiral Ligand Architecture

7,7′-Dihydroxy-8,8′-biquinolyl was converted to the title phosphine in four-steps via Mitsunobu monoetherification, trifylation, phosphination, and phosphine oxide reduction (63% overall yield). Enantiomerically pure phosphine was combined with Pd2dba3 and investigated for the synthesis of axially chiral biaryl compounds from Ar1Br and Ar2B(OH)2 in the presence of K3PO4 in toluene solvent (6 examples, 4–97% yield, 4–74% ee). The analogous carbocyclic ligand 2-(diphenylphosphino)-2′-methoxy-1,1′-binaphthyl (MOP) was studied for comparative purposes and found to be effective for the synthesis of hindered 2,2′-disubstituted 1,1′-binaphthyls (78–83% yield, 20–38% ee).

ChemInform Abstract: A General Pd‐Catalyzed Decarboxylative Cross‐Coupling Reaction Between Aryl Carboxylic Acids: Synthesis of Biaryl Compounds.

AbstractThe use of a Pd(II)/PCy3 catalyst enables the cross‐coupling of electronically different or electronically similar aryl carboxylic acids.

A General Pd‐Catalyzed Decarboxylative Cross‐Coupling Reaction between Aryl Carboxylic Acids: Synthesis of Biaryl Compounds

Säure trifft Säure: Bei der hier vorgestellten Synthese von Biarylen durch decarboxylierende Kreuzkupplung von (Hetero)arencarbonsäuren (siehe Schema) können elektronisch ähnliche ebenso wie unterschiedliche Arencarbonsäuren miteinander gekuppelt werden. Die Substrate können Nitro-, Cyan-, Fluor-, Chlor-, Brom-, Trifluormethyl- oder Methoxysubstituenten tragen. Detailed facts of importance to specialist readers are published as ”Supporting Information”. Such documents are peer-reviewed, but not copy-edited or typeset. They are made available as submitted by the authors. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.

ChemInform Abstract: Synthesis of Biaryl Compounds Using Tandem Ruthenium‐Catalyzed Ring‐Closing Metathesis.

AbstractA new method for the construction of various biaryl compounds is presented involving a tandem ring‐closing enyne metathesis and ring‐closing olefin metathesis of tetraenynes.

ChemInform Abstract: Liquid‐Phase Synthesis of Biaryl Compounds by the Hydrogenolysis of Pentaerythritol‐Supported Biarylsulfonates.

AbstractPentaerythritol turns out to be an efficient soluble tetrapodal support permitting the traceless release of various biaryl compounds attached by a sulfonate linkage.

Synthesis of Biaryl Compounds Using Tandem Ruthenium‐Catalyzed Ring‐Closing Metathesis

Tandem ring-closing enyne metathesis (RCEM)/ring-closing olefin metathesis (RCM) of tetraenynes with Grubbs second-generation catalyst, followed by elimination, was found to be a new and efficient synthetic approach to biaryl compounds. A preliminary asymmetric version of this approach, which used homochiral Ru-alkylidene catalysts, is also presented.

ChemInform Abstract: Synthesis of Biaryl Compounds Through Three‐Component Assembly: Ambidentate Effect of the tert‐Butyldimethylsilyl Group for Regioselective Diels—Alder and Hiyama Coupling Reactions.

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.