Palladium-catalyzed Suzuki-Miyaura Cross-coupling Reaction Research Articles

Synthesis, characterization and catalytic activity of palladium complexes with α-imino–amidos ligands

In the present work, a series of steric substituted α-imino–amido palladium complexes, {[Ar–NC(CH3)–C(CH3)(R)–NH–Ar]PdCl2} (C1, R = Me, Ar = 2,6-dimethylphenyl; C2, R = Me, Ar = 2,6-diisopropylphenyl; C3, R = CH2Ph, Ar = 2,6-dimethylphenyl; C4, R = CH2Ph, Ar = 2,6-diisopropylphenyl), were synthesized and characterized. The structures of palladium complexes C3 and C4 were elucidated by X-ray diffraction. These bidentate nitrogen ligands were applied in palladium-catalyzed Suzuki–Miyaura cross-coupling reactions. The effect of ligand substitution as well as reaction conditions on catalytic activity was evaluated. Under the optimization process, the less bulky and electron-donating ligand were successfully used to catalyze the reaction of a variety of aryl bromides and chlorides with arylboronic acids, giving the desired biaryl products in high yields.

Pd-Catalyzed Suzuki–Miyaura Cross-Coupling Reactions between Sulfamates and Potassium Boc-Protected Aminomethyltrifluoroborates

Sulfamates were studied as the electrophilic partners in the palladium-catalyzed Suzuki-Miyaura cross-coupling reaction with potassium Boc-protected primary and secondary aminomethyltrifluoroborates. A broad range of substrates was successfully coupled to provide the desired products. Complex molecules containing a new carbon-carbon bond and an aminomethyl moiety could be prepared through this developed method.

ChemInform Abstract: Efficient Salicylaldimine Ligands for a Palladium‐Catalyzed Suzuki—Miyaura Cross‐Coupling Reaction.

A series of salicylaldimine ligands were designed to promote palladium-catalyzed Suzuki–Miyaura cross-coupling reaction. After a screening process, a ligand with a bulky 2,4-di-tert-butyl substituent on the salicyaldehyde backbone and cyclohexylamine moiety was found to serve as a good combination for this reaction in aqueous solutions of DMF. The protocol demonstrated a significant advance in the efficiency of the cross-coupling of aryl bromides and aryl chlorides with arylboronic acids to produce the desired biaryl products. Copyright © 2012 John Wiley & Sons, Ltd.

Suzuki–Miyaura Cross-Coupling Reactions of Potassium Boc-Protected Aminomethyltrifluoroborate with Aryl and Hetaryl Mesylates

Palladium-catalyzed Suzuki-Miyaura cross-coupling reactions were studied with potassium Boc-protected aminomethyltrifluoroborate through C-O activation of various mesylate derivatives to afford the corresponding products in moderate to good yields.

Efficient Pyrimidone-Promoted Palladium-Catalyzed Suzuki-Miyaura Cross-Coupling Reaction

An efficient Pd(OAc)2/orotic acid catalytic system has been developed for Suzuki–Miyaura cross-coupling reaction of halides with aryl- and vinylboronic acids. The use of pyrimidone as ligand makes this method useful and attractive for the synthesis of stilbenes and derivative compounds. An attractive feature of this method is the tolerance of functional groups in both substrates.

ChemInform Abstract: Recent Applications of the Suzuki—Miyaura Cross—Coupling to Complex Polycyclic Ether Synthesis

AbstractReview: ca. 100 refs.

Palladium-catalyzed Suzuki–Miyaura cross-coupling reaction of potassium 2-pyridyl trifluoroborate with aryl (heteroaryl) halides

Palladium-catalyzed Suzuki–Miyaura cross-coupling reaction of potassium pyridine-2-trifluoroborates and various aryl (heteroaryl) halides can generate the corresponding desired coupling products with moderate to good yields. It can be carried out under the conditions with ethanol as solvent, Pd(OAc) 2 and SPhos as catalyst system and Na 2CO 3 as a base.

Microwave promoted palladium-catalyzed Suzuki–Miyaura cross-coupling reactions of 6-chloropurines with sodium tetraarylborate in water

An efficient method for the synthesis of 6-arylpurines (nucleosides) was developed via Suzuki–Miyaura cross-coupling reactions of 6-chloropurines (nucleosides) and sodium tetraarylborate in neat water (ethanol). The process gave good to high isolated yields within a short reaction time under microwave irradiated conditions.

Efficient and Original Microwave-Assisted Suzuki-Miyaura Cross-Coupling Reaction in the 4H-Pyrido[1,2-a]pyrimidin-4-one Series

An efficient synthesis of new series of various 3-aryl, 3-heteroaryl, and 3-styryl-4H-pyrido[1,2-a]pyrimidin-4-ones by palladium-catalyzed Suzuki-Miyaura cross-coupling reactions using microwave irradiation is described. The coupling process is tolerant of electron-poor, electron-rich, and bulky boronic acid derivatives, and leads to the desired products in good yields.

Suzuki–Miyaura cross-coupling reaction on copper-trans-A2B corroles with excellent functional group tolerance

The palladium-catalyzed Suzuki–Miyaura cross-coupling reaction has been investigated on meso-substituted trans-A2B-corrole using tailored Pd-catalyst systems.We present the first examples of Suzuki–Miyaura cross-coupling reactions on meso-substituted trans-A2B-corrole derivatives with neutral, sterically hindered, inactivated and heteroaromatic boronic acids and esters, alkenylboronic acids, as well as quickly deboronating aryl boronic acids and benzo-condensated five membered heterocyclic boronic acids. In addition, we established a high-yield procedure for the Suzuki–Miyaura cross-coupling reaction of corroles with neutral boronic acids.Due to the lability of the free-base corrole macrocycles, functionalization of the corrole periphery was performed with the corresponding Cu-metallated species. meso-Substituted trans-A2B-corrole can hence be regarded as highly versatile platform towards more sophisticated corrole systems.X-ray structure analysis of a functionalized meso-substituted trans-A2B copper corrole exhibited the typical features of such a Cu-complex: short N–Cu distances and a saddled corrole configuration.Moreover, we observed a sensitivity of the formal oxidation state of the coordinated copper ions towards Suzuki–Miyaura cross-coupling reaction conditions, where the central copper(III) ion approaches the characteristic features of a copper(II) species. This redox behaviour was examined by UV/vis absorption spectra, nuclear magnetic resonance (NMR) experiments and time-dependent density functional theoretical calculations.

A palladium chelating complex of ionic water-soluble nitrogen-containing ligand: the efficient precatalyst for Suzuki–Miyaura reaction in water

An ammonium-functionalized water-soluble bidentate nitrogen-containing ligand (3) and its palladium chelating complex (4) have been easily prepared from the commercial available starting materials in high overall yields. The charge distributions and molecular orbital analyses of 3, 4 and non-ionic hydrophobic analogue (2a) based on the optimized structures were implemented. The crystal structure of 4 has been established by single-crystal X-ray diffraction. The water-soluble palladium complex was a much more effective catalyst than 2a in palladium-catalyzed Suzuki–Miyaura cross-coupling reaction in air and pure water. High catalytic activity of aryl chlorides and aryl bromides was observed. The mercury drop test, poison experiments and TEM analysis of the catalytic solution showed Pd(0) were involved in catalysis. The palladium nanoparticles of 3.0 ± 0.6 nm were formed after the catalytic reaction, they were stabilized by synergetic effect of coordination and electrostatic interactions from the ammonium-functionalized chelating ligand. No precipitate was observed when the aqueous nanoparticles were stored in air for months.

Recent Applications of the Suzuki-Miyaura Cross-coupling to Complex Polycyclic Ether Synthesis

The ladder-shaped polycyclic ether marine natural products present formidable and challenging synthetic targets due to their structural complexity, and exceptionally potent biological activities. Over the past decade, however, the limited availability of these substances from natural sources has precluded detailed biological studies. There has been an urgent need for means to supply useful quantities of these natural products and their analogues by total synthesis. We have developed a highly convergent strategy for the rapid and efficient assembly of polycyclic ether arrays, which relies on the palladium-catalyzed Suzuki-Miyaura cross-coupling reaction of cyclic enol triflates or phosphates. The utility of this strategy has been demonstrated by its application to the convergent total synthesis of the polycyclic ether class of natural products.

Suzuki–Miyaura cross-coupling reactions of halo derivatives of 4H-pyrido[1,2-a]pyrimidin-4-ones

The palladium-catalyzed Suzuki-Miyaura cross-coupling reactions of halo derivatives of 4H-pyrido[1,2-a]pyrimidin-4-one with (het)arylboronic acids allow easy access to (het)aryl and vinyl derivatives of this bicycle in good to excellent yields, even from chloro derivatives. The sequence of reactivity of the halogen in the different positions of the ring system was also investigated. 6-Phenyl-4H-pyrido[1,2-a]pyrimidin-4-one could be prepared by thermal cyclization of isopropylidene (6-phenylpyrid-2-ylamino)methylenemalonate, together with a small amount of 7-phenyl-1,4-dihydro-1,8-naphthyridin-4-one.

Synthesis of (2S)-isopropyl-5-alkynylpyrimidin-2-ones: precursors of β-aminoacids

The efficient palladium-catalyzed Suzuki-Miyaura cross-coupling reaction of (2S)-isopropyl-5-iodo-2,3-dihydro-4(H)-pyrimidin-4-one with, arylethynyl-, heteroarylethynyl-, and alkylethynyltrifluoroborate salts is reported. The standard protocol was evaluated and optimized in order to gain access to suitable precursors of enantiopure 2-substituted β-amino acids. The scope and limitations of this methodology are discussed.

Effect of counterions and central cores of tripodal imidazolium salts on palladium-catalyzed Suzuki–Miyaura cross-coupling reactions

Seven tripodal imidazolium salts were synthesized and used as catalyst precursors in cross-coupling reactions of aryl halides with arylboronic acids. Effect of counterions and central cores of seven tripodal imidazolium salts was investigated. The tripodal imidazolium salt anchored to benzene with anion PF 6 − was found most effective with Pd(OAc) 2 for the cross-coupling of aryl bromides with arylboronic acids.

Efficient Microwave-Assisted Palladium-Catalyzed Suzuki-Miyaura Cross-Coupling Reactions in 5-Nitroimidazole Series

A new simple, rapid and high yielding synthesis (mean yield = 83%) of various 4-aryl, 4-heteroaryl, and 4-styryl-1,2-di­methyl-5-nitro-1H-imidazoles by palladium-catalyzed Suzuki-Miyaura cross-coupling reactions using microwave irradiation is described.

A Retrospective on the Design and Synthesis of Novel Molecules through a Strategic Consideration of Metathesis and Suzuki–Miyaura Cross‐Coupling

In recent years, ruthenium-catalyzed metathesis and palladium-catalyzed Suzuki-Miyaura cross-coupling reactions have proven to be the most efficient tools for carbon-carbon bond formation in synthetic organic chemistry. This is mainly because of the stability and remarkable functional-group tolerance of these catalysts. Therefore, the strategic consideration of these two powerful reactions can eventually minimize the synthetic steps for the construction of complex target molecules. In this perspective we summarize the efforts of many research groups who have used the combination of these two powerful reactions (either together in concert or separated by a few multistep sequences) for the synthesis of supramolecular ligands, polyaromatic compounds, and complex natural products.

A new homogeneous polymer support based on syndiotactic polystyrene and its application in palladium-catalyzed Suzuki–Miyaura cross-coupling reactions

Soluble syndiotactic polystyrene-supported triphenylphosphine (sPS–TPP) was synthesized by reacting borylated syndiotactic polystyrene with (4-bromophenyl)diphenylphosphine. A palladium catalyst, supported on sPS–TPP, effectively catalyzed Suzuki–Miyaura coupling reactions of aryl halides under homogeneous conditions. The polymer-supported palladium complex was recovered quantitatively by adding an equal volume of poor solvent to the polymer, and coupling products could be easily isolated by evaporating the solvents. The recovered polymer complex was reused several times without significant loss of activity.

Palladium-catalyzed Suzuki–Miyaura cross-coupling reaction of organoboronic acids with N-protected 4-iodophenyl alanine linked isoxazoles

Suzuki–Miyaura coupling reaction of N-protected 4-iodopheyl alanine isoxazoles with arylboronic acids, catalyzed by palladium, efficiently produce benzyl- N-(4-bipheyl)-2-(3-methyl-5( E)-2-aryl-1-ethenyl-4- isoxazolyl)-amino-2-oxoethyl) carbamates in good yields. This process is first of its kind to construct carbon–carbon bond formation having biaryl motif on amino acid linked isoxazole moiety.

Density Functional Studies on Palladium‐Catalyzed Suzuki–Miyaura Cross‐Coupling Reactions Assisted by N‐ or P‐Chelating Ligands

DFT studies with the B3LYP functional have been carried out on the Suzuki-Miyaura cross-coupling reactions of phenyl chloride and phenylboronic acid catalyzed by palladium complexes with N- or P-chelating ligands. The full catalytic cycle, from the addition of reactants to the catalyst to the release of the cross-coupled product from the complexed intermediate, has been examined. The stages within the cycle, such as oxidative addition, transmetalation, and reductive elimination, were validated by linking the mechanistically relevant intermediates and transition states. Various derivatives of diimine, diphosphine, and diamine were considered as potential model ligands. The catalytic reaction employing diimine as the chelating ligand has been verified as the one with the most energetically feasible route.