Miyaura Cross-coupling Research Articles

Synthesis of New Highly Functionalized 1H-Indole-2-carbonitriles via Cross-Coupling Reactions

An approach for the preparation of polysubstituted indole-2-carbonitriles through a cross-coupling reaction of compounds 1-(but-2-ynyl)-1H-indole-2-carbonitriles and 1-benzyl-3-iodo-1H-indole-2-carbonitriles is described. The reactivity of indole derivatives with iodine at position 3 was studied using cross-coupling reactions. The Sonogashira, Suzuki–Miyaura, Stille and Heck cross-couplings afforded a variety of di-, tri- and tetra-substituted indole-2-carbonitriles.

Recent Advances in Synthesis and Uses of Heterocycles-based Palladium(II) Complexes as Robust, Stable, and Low-cost Catalysts for Suzuki- Miyaura Crosscouplings

C-C cross-couplings constitute the largest diversity of organic reactions of chemical, biomedical, and industrial significance. They are also among the most frequently encountered reactions used in the synthesis of numerous drugs and relevant pharmaceutical substances. Development of an easily accessed, efficient, stable, and low cost catalyst is an attractive area of research in such kind of organic synthesis. This review highlights the remarkable and recent achievements made recently in the synthesis and use of palladium(II) complexes catalysts, that are based on heterocycles as ligands in their constitution, in the Suzuki-Miyaura cross-coupling.

Green Bio-Based Solvents in C-C Cross-Coupling Reactions

Solvent accounts for majority of the waste derived from synthetic transformations. This implies that by making changes to the solvent used by either switching to greener options, reducing the volume of solvent used, or even better avoiding the use of solvent totally will have a positive impact on the environment. Herein, the focus will be on the use of bio-based-green-solvents in C-C crosscoupling reactions highlighting the recent developments in this field of research. Emphasis in this review will be placed on developments obtained for Mizoroki-Heck, Hiyama, Stille, and Suzuki- Miyaura cross-couplings. For these cross-coupling reactions, good reaction conditions utilizing green solvents are now available.

Advanced Approaches to Post-Assembly Modification of Peptides by Transition-Metal-Catalyzed Reactions

We have summarized diverse synthetic approaches for the modification of peptides by employing transition-metal-catalyzed reactions. These methods can deliver unusual peptides suitable for peptidomimetics. To this end, several popular reactions such as Diels–Alder, 1,3-dipolar cycloaddition, [2+2+2] cyclotrimerization, metathesis, Suzuki­–Miyaura cross-coupling, and Negishi coupling have been used to assemble modified peptides by post-assembly chemical modification strategies.1 Introduction2 Synthesis of a Cyclic α-Amino Acid Derivative via a Ring-Closing Metathesis Protocol3 Peptide Modification Using a Ring-Closing Metathesis Strategy4 Peptide Modification via a [2+2+2] Cyclotrimerization Reaction5 Peptide Modification by Using [2+2+2] Cyclotrimerization and Suzuki Coupling6 Peptide Modification via a Suzuki–Miyaura Cross-Coupling7 Peptide Modification via Cross-Enyne Metathesis and a Diels–Alder­ Reaction as Key Steps8 Peptide Modification via 1,3-Dipolar Cycloaddition Reactions9 Modified Peptides via Negishi Coupling10 A Modified Dipeptide via Ethyl Isocyanoacetate11 Conclusions

Synthesis of Polyoxygenated Biphenyls

Background: Construction of biaryls containing polyoxygenated groups via the palladiumcatalyzed Suzuki-Miyaura cross-coupling reaction of aryl halides with organoboronic acids is a very interesting area of research. A number of functionalized polyoxygenated biphenyls have received considerable attention during the past decades, due to their presence as the structural motifs in natural products with diversified biological activities. Due to the particular pharmaceutical interest concerning the specific substitution pattern of a biphenyl scaffold, several synthetic methods have been developed. On the basis of investigation, we developed a novel Suzuki-Miyaura cross-coupling route for preparing polyoxygenated biphenyls. Keywords: Baeyer-Villiger deformation, Claisen rearrangement, Olefin migration, Oxidative cleavage, Polyoxygenated biphenyls, Suzuki- Miyaura cross-coupling.

Suzuki-Miyaura Cross-Coupling Reaction Catalyzed by Supported Palladium Under Microwave Irradiation

Organic synthesis efficiency can take considerable advantage from microwave heating. Compared to conventional heating, it allows to improve the reactions speed and yield through an energy-efficient, clean, and easy-to-use processing tool. Transition-metal catalyzed cross-coupling reactions and in particular the Suzuki- Miyaura cross-coupling is powerful and widely used tool for the formation of carbon-carbon bonds. Crosscoupling reactions are of large interest for the bonding of a broad range of functional groups, in particular biaryl groups, allowing for a strong stereoselectivity. In this paper, recent research results concerning the application of microwave heating in Suzuki-Miyaura cross-coupling reactions are reviewed with particular emphasis on reactions involving supported Pd as a catalyst. Keywords: Microwave chemistry, Suzuki-Miyaura reaction, supported palladium, C-C bond formation, organoboron compounds, crosscoupling.

Palladium-Alumoxane Framework as a Novel and Reusable Nanocatalyst for Suzuki–Miyaura, Stille and Heck Cross Coupling Reactions

Herein for the first time, a Schiff base alumoxane-supported palladium (SBA-Pd°) were successfully synthesized and reported as a new mesoporous nanocatalyst for C–C cross coupling reactions. The SBA-Pd° nanocatalyst could be dispersed in poly(ethylene glycol) and showed excellent catalytic activity for Suzuki–Miyaura, Stille and Heck coupling reactions. In addition, the nanocatalyst could be recovered and reused several times without significant loss of its catalytic activity. Pd leaching from SBA-Pd° is very negligible for this coupling reaction.

Verstile silver(I) and nickel(II) NHC complexes bearing benzotriazole-function: Synthesis, fluorescence and catalytic property

The imidazolium salts [(N-alkyl-imidazolyl) methyl] benzotriazole hexafluorophosphate (L1H: alkyl = n-C4H9, L2H: alkyl = picoly, L3H: alkyl = 9-anthrylmethyl, L4H: alkyl = 1-naphthylmethyl) have been prepared. Mononuclear N-Heterocyclic carbene silver complexes: L1AgPF6 (1), L2AgPF6 (2), L3AgPF6 (3) were synthesized in DMSO. Transmetalation reactions afford the synthesis of the nickel(II) complex L2Ni(PF6)2 (4). Furthermore, L2H, L3H and L4H were treated with silver oxide in CH3CN to afford other complexes (5, 6 and 7). The complexes 5 and 6 formed 1D and 2D supramolecular chains by AgN bond and intermolecular π-π interactions, respectively, which were found that the carbene carbon atoms of NHCs are not coordinated to silver atom. However, in Complex 7, silver atoms selectly bind to nitrogen atoms of benzotriazoles and carbon atoms of imidazoles, which afford the dinuclear Ag metallamacrocycles. Complexes 1–7 were characterized by single crystal X-ray diffraction, NMR spectroscopy, elemental analysis and powder X-ray diffraction. The catalytic activity of NHCNi complex 4 for Suzuki−Miyaura cross-coupling was studied.

ChemInform Abstract: Chemoselective One‐Pot Synthesis of Terphenyl Derivatives by Sequential Directed C—H Functionalization‐Suzuki Coupling.

A simple and efficient route for the preparation of terphenyl derivatives via palladium-catalyzed sequential directed C―H arylation/Suzuki–Miyaura cross-coupling in ‘one-pot’ has been developed. 4,4′-(Cyclohexane-1,1-diyl)diphenol is an essential ligand. This reaction can tolerate a series of functional groups and provides the terphenyl derivatives in moderate to good yield. Copyright © 2014 John Wiley & Sons, Ltd.

Synthesis of 3-Aryl-2-arylamidobenzofurans Based on the Curtius Rearrangement

The synthesis of novel 3-aryl-2-arylamidobenzofurans has been accomplished via a Curtius rearrangement strategy in four steps from benzofuran-2-carboxylic acids. The requisite Suzuki-Miyaura cross-coupling, with benzyl 3-bromobenzofuran-2-ylcarbamate or 2-arylamido-3-bromobenzofurans, revealed an unusual reductive debromination process due to the presence of the free NH group. This dehalogenation can be suppressed by N-alkylation. DMAP is an efficient reagent for the one-pot conversion of benzyl benzofuran-2-ylcarbamates into the corresponding benzofuran-2-arylamides through aroylation, thus acting both as an acyl transfer reagent and a deprotecting agent of the Cbz group. A mechanism is postulated.

Postsynthetic Guanine Arylation of DNA by Suzuki−Miyaura Cross-Coupling

Direct radical addition reactions at the C(8)-site of 2'-deoxyguanosine (dG) can afford C(8)-Ar-dG adducts that are produced by carcinogenic arylhydrazines, polycyclic aromatic hydrocarbons, and certain phenolic toxins. Such modified nucleobases are also highly fluorescent for sensing applications and possess useful electron transfer properties. The site-specific synthesis of oligonucleotides containing the C(8)-Ar-G adduct can be problematic. These lesions are sensitive to acids and oxidants that are commonly used in solid-phase DNA synthesis and are too bulky to be accepted as substrates for enzymatic synthesis by DNA polymerases. Using the Suzuki-Miyaura cross-coupling reaction, we have synthesized a number of C(8)-Ar-G-modified oligonucleotides (dimers, trimers, decamers, and a 15-mer) using a range of arylboronic acids. Good to excellent yields were obtained, and the reaction is insensitive to the nature of the bases flanking the convertible 8-Br-G nucleobase, as both pyrimidines and purines are tolerated. The impact of the C(8)-Ar-G lesion was also characterized by electrospray ionization tandem mass spectrometry, UV melting temperature analysis, circular dichroism, and fluorescence spectroscopy. The C(8)-Ar-G-modified oligonucleotides are expected to be useful substrates for diagnostic applications and understanding the biological impact of the C(8)-Ar-G lesion.

Synthesis of Hyperbranched Poly(m-phenylene)s via Suzuki Polycondensation of a Branched AB2 Monomer

An efficient synthesis of hyperbranched poly(m-phenylene)s is achieved by Suzuki polycondensation of a m-terphenyl-derived branched AB2 monomer. The resulting hyperbranched polymers show high molecular weight and relatively low polydispersity and are readily soluble in common organic solvents. A catalyst system composed of Pd(OAc)2 and S-Phos was found to be highly active in the present Suzuki polycondensation protocol. The molecular weight and polydispersity of the polymer are controllable by varying the catalyst loading and the starting monomer concentration. Experimental results are consistent with a pseudo-chain-growth pathway that involves intramolecular catalyst transfer during polymerization. Furthermore, the triflate end groups of the hyperbranched poly(m-phenylene)s can be efficiently converted to other functionalities via in situ Suzuki−Miyaura cross-couplings.

Chemoselective and Regiospecific Suzuki Coupling on a Multisubstituted sp3-Carbon in 1,1-Diborylalkanes at Room Temperature

The palladium-catalyzed Suzuki-Miyaura cross-coupling on a multisubstituted sp(3)-carbon in 1,1-diborylalkanes was achieved at room temperature. The generation of a monoborate intermediate by virtue of the adjacent B atom could result in the chemoselective coupling reaction under ambient conditions.

Enantioselective Total Synthesis of the Potent Anti-inflammatory (+)-Myrrhanol A

The first total synthesis of potent anti-inflammatory polypodanes (+)-myrrhanol A (1), (+)-myrrhanone A (2), (+)-myrrhanone B (3), and (+)-myrrhanol B (4) has been achieved. Key steps in our convergent, highly stereocontrolled route are a Ti(III)-mediated radical cyclization of a chiral monoepoxide to furnish a bicyclic synthon that combines stereospecifically with an acyclic vinyl iodide via an intermolecular B-alkyl Suzuki-Miyaura cross-coupling.

Chemistry of bis(2-ethynyl-3-thienyl)arene and related systems. Part 6: preparation of 1,4-bis(2-ethynyl-3-thienyl)benzene derivatives containing fluorine atoms at the 2,3- or 2,5-positions of the benzene ring

Fluorine-substituted 1,4-bis(2-ethynyl-3-thienyl)benzene derivatives were prepared, utilizing Suzuki–Miyaura and Sonogashira cross coupling reactions. Their UV spectra were compared with some related compounds.

Total Synthesis of Jatrophane Diterpenes from Euphorbia characias

The enantioselective total synthesis of the jatrophane diterpene (-)-15-O-acetyl-3-O-propionylcharaciol is described. Starting from an advanced cyclopentane building block, a B-alkyl Suzuki-Miyaura cross-coupling and carbonyl addition were utilized to assemble a fully functionalized triene, and a ring-closing metathesis was then employed to construct the rigid 12-membered ring. Twenty-five years after the original report on the isolation of the natural product, our total synthesis unambiguously corroborates the original tentative structural assignment.

Utilization of Potassium Vinyltrifluoroborate in the Development of a 1,2-Dianion Equivalent

Previous studies of orthogonally reactive dibora species led to the discovery of a unique reactivity pattern associated with potassium vinyltrifluoroborate. Upon hydroboration, the vinyltrifluoroborate generates a 1,2-diboraethane, which is distinct from the 1,1-dibora intermediates generated when traditional alkenyldialkylboron species undergo hydroboration. The 1,2-dianion equivalent thus generated can be envisioned as a building block for the linkage of two different electrophiles via palladium-catalyzed Suzuki-Miyaura cross-couplings.

A New Approach to the Synthesis of 4-Hydroxyethylsulfonylstyrene

A new, more environmentally benign route to hydroxyethylsulfonylstyrene has been developed, starting from 4-bromobenzenethiol, involving a solventless thioether formation, water-based perborate oxidation, and Suzuki−Miyaura cross coupling with a vinylborate reagent.

Micellar Catalysis of Suzuki−Miyaura Cross-Couplings with Heteroaromatics in Water

Pd-catalyzed couplings involving several heteroaromatic halides (bromides and chlorides) as well as boronic acids can be done under exceedingly mild conditions (between rt and 40 degrees C) in pure water using commercially available Pd catalysts and PTS, a nanomicelle-forming amphiphile.

C2-Symmetric Bis-Hydrazones as Ligands in the Asymmetric Suzuki−Miyaura Cross-Coupling

Glyoxal bis-hydrazone derived from (S,S)-1-amino-2,5-diphenylpyrrolidine behaves as an excellent ligand for phosphine-free, asymmetric Suzuki-Miyaura cross couplings, thereby affording a variety of enantiomerically enriched biaryls with different substitution patterns. The high catalytic activity of the [PdCl2(bis-hydrazone)] complex allows reactions to be performed at room temperature, affording products with excellent enantioselectivities in all cases.