Synthesis of substituted 2-phenylhistamines via a microwave promoted Suzuki coupling

Substitutions on the 2-position of the imidazole ring of histamine have proven useful in a number of biochemical settings. Current art for the synthesis of these constructs relies upon a cumbersome and low-yielding condensation reaction. Here-in we report a new procedure for the synthesis of a series of substituted 2-phenylhistamines utilizing a microwave-promoted Suzuki coupling.     

Suzuki coupling for protein modification

Suzuki-coupling, a representative cross-coupling reaction between small molecules, can proceed on a protein surface in aqueous solution under mild conditions. The modified protein produced by the coupling reaction maintained its native like structure and function. In addition, fluorescent dye appended-protein acts as a fluorescent biosensor.     

An effective synthesis of β-aryl substituted isotetronic acids via Suzuki coupling

Isotetronic acids are of great agricultural and pharmacological relevance and occur in a number of natural products. A convenient synthetic pathway to β-aryl substituted isotetronic acid derivatives was developed via Suzuki cross-coupling of the corresponding β-bromo substituted isotetronic acid derivatives with arylboronic acids under palladium acetate catalysis. Good to excellent yields have been achieved     

An effective synthesis of β-aryl substituted isotetronic acids via Suzuki coupling

lsotetronic acids are of great agricultural and pharmacological relevance and occur in a number of natural products.A convenient synthetic pathway to β-aryl substituted isotetronic acid derivatives was developed via Suzuki cross-coupling of the corresponding β-bromo substituted isotetronic acid derivatives with arylboronic acids under palladium acetate catalysis.Good to excellent yields have been achieved.     

Nickel-promoted ligand-free palladium-catalyzed Suzuki coupling reaction

Summary A Ni-promoted ligand free palladium catalyst system for Suzuki coupling of aryl bromides has been developed in high efficiency under mild reaction conditions. It was obtained in situ by introducing NiCl₂ to PdCl₂/PVP using a parallel high-throughput screening technique. A wide range of aryl bromides bearing a variety of functional groups was evaluated.     

Efficient synthesis of isoflavone analogues via a Suzuki coupling reaction

Analogues of 3-aryl-8-isobutyl-5,6,7-trihydroxy-2-methyl-4H-chromen-4-one were synthesized with high yields via the Suzuki coupling reaction of 3-iodo-8-isobutyl-5,6,7-trimethoxy-2-methyl-4H-chromen-4-one with different aryl boronic acids.     

A convenient synthesis of 4-aryl-1,8-naphthyridin-2(1H)-ones by the Suzuki coupling

4-Halo-1,8-naphthyridin-2(1H)-ones readily available from 2-chloronicotinic acid were subjected to the Suzuki coupling reaction with arylboronic acids to give a diversity of 4-aryl-1,8-naphthyridin-2(1H)-ones.     

N-Acylsuccinimides: Efficient acylative coupling reagents in palladium-catalyzed Suzuki coupling via CN cleavage

An acylative Suzuki coupling of activated amides with aryl boronic acids has been reported via palladium-catalyzed CN bond cleavage. This protocol demonstrate amides can be activated by an atom-economic and cheap succinimide, which can be efficiently utilized to synthesize broad array of diaryl ketones in moderate to good yields.     

Design of a capillary-microreactor for efficient Suzuki coupling reactions

A Pyrex glass capillary (0.4 mm internal diameter) microreactor was developed and used for Suzuki coupling reactions. Capillary-microreactors are more attractive than photolithographic microfluidic devices in terms of simplicity, low cost and ease of handling. Compared with the conventional synthesis procedure, our approach of using a capillary-microreactor offers a convenient and highly efficient means to optimize reaction conditions and the performance of catalysts. The procedure exhibits good precision, reproducibility and high reaction yield for a range of reactants investigated.     

Ligand effects in palladium‐catalyzed Suzuki and Heck coupling reactions

A range of sterically hindered diimine ligands and their palladium (II) complexes were synthesized. These compounds were fully characterized by elemental analysis, ¹H and ¹³C‐NMR spectroscopy. The use of the palladium complexes as catalysts for Suzuki and Heck coupling has been studied in an attempt to demonstrate the effect of side groups on catalytic activity. It was clearly seen that the location of side ? CH₃ groups which bound to benzene ring had little effect on catalytic activity. Interestingly when we changed these ? CH₃ groups with ? Cl groups the activity of the complexes increased. On the other hand, side groups which bound to imine nitrogen also had a large effect on catalytic activity. Copyright © 2008 John Wiley & Sons, Ltd.     

含有酯基二茂铁亚胺环钯化合物催化Suzuki和Heck反应

合成并表征了系列含有酯基二茂铁亚胺环钯化合物.结果表明,该系列环钯催化剂在纯水或有机溶剂中均能高效催化Heck和Suzuki偶联反应.     

Functionalization of silica gel by ultrasound-assisted surface Suzuki coupling

Mesoporous silica gel was functionalized by various organic functional groups using thiol-ene coupling of surface thiol groups with 4-vinylphenylboronic acid followed by Suzuki coupling with aromatic halides. For better performance, the synthesis was conducted under sonication. The presence of surface functional groups was confirmed by thermoanalysis, FT-IR spectroscopy and characteristic reactions of these groups. Solid-phase conditions of the synthesis eliminate the risk of side reactions of boronic acids.     

Synthesis of biaryl-styrene monomers by microwave-assisted Suzuki coupling

Biaryl-styrenic monomers are prepared via Suzuki coupling as functional monomers in the synthesis of molecularly imprinted polymers. Traditional thermal Suzuki approaches are hampered by competition between Suzuki, Heck and homo-coupling reactions. Microwave-assisted approaches facilitated rapid access to the desired Suzuki products whilst suppressing both Heck and homo-couplings of 4-vinylboronic acid.     

A highly efficient catalyst for Suzuki coupling of aryl halides and bromoarylphosphine oxides

The biphenyl-based phosphine, P(o-C₆H₄C₆H₄Me)Ph₂, is a moderately bulky and electron-rich phosphine, which has been successfully applied to the palladium catalyzed Suzuki coupling of activated and deactivated aryl halides as well as bromoarylphosphines and bromoarylphosphine oxides, with low catalyst loading and good to excellent conversions and turnovers.     

Preparation of highly functionalized 1,5-disubstituted tetrazoles via palladium-catalyzed Suzuki coupling

The preparation of a range of 1,5-disubstituted tetrazoles has been achieved through palladium-catalyzed Suzuki coupling. Using appropriately substituted 5-p-toluenesulfonyltetrazoles as substrates (obtained by cycloaddition of a substituted azide with p-toluenesulfonyl cyanide), this methodology provides access to a variety of highly substituted tetrazoles that would be difficult to access otherwise. The procedure is compatible with functional groups commonly found in drug-like molecules, and has been used to generate a number of compounds of potential biological interest.     

Synthesis of a dicyclobutylideneethane derivative via sequential palladium-catalyzed Miyaura borylation and Suzuki coupling

An efficient synthesis of a dicyclobutylideneethane derivative was achieved using a palladium-catalyzed reaction of a substituted (bromomethylene)cyclobutane with bis(pinacolato)diboron. The reaction mechanism was investigated in detail. The Suzuki cross-coupling reaction of a (bromomethylene)cyclobutane with arylboronic acid was also achieved.     

Design and synthesis of potential β-sheet nucleators via Suzuki coupling reaction

Three series of compounds characterized by biphenylic structure were synthesized in order to develop new scaffolds able to induce β-sheet folding in the peptides. Microwave flash heating was used in order to shorten reaction times and to enhance the obtained yields. Simulated annealing molecular dynamics simulations demonstrated that some of the compounds were capable of adopting a 15-membered intramolecularly hydrogen-bonded conformation, which supports an antiparallel β-sheet structure.     

Tandem cycloisomerization/Suzuki coupling of arylethynyl MIDA boronates

A tandem gold-catalyzed cycloisomerization/Suzuki cross-coupling sequence involving arylethynyl-N-methyliminodiacetic acid boronates is described. Combining the mildness of homogeneous gold catalysis with the versatility of N-methyliminodiacetic acid (MIDA) boronates, this tandem two-step method enables the rapid assembly of various aryl-substituted heterocycles without having to isolate or purify any heterocyclic MIDA boronate intermediates. Another major advantage of this method is that a wide range of heterocycles bearing different aryl groups may be made from a single MIDA boronate alkyne precursor.     

In-situ synthesis of a palladium-polyaniline hybrid catalyst for a Suzuki coupling reaction

Palladium-catalyzed cross-coupling reactions are one of the most frequently used synthetic tools for the construction of new carbon-carbon bonds in organic synthesis. The present study describes the use of palladium-polyaniline composite material as a catalyst for the Suzuki coupling of aryl halides. Palladium-polyaniline nanocomposite material was synthesized using an in-situ technique in which palladium acetate and aniline hydrochloride were used as the precursors of the composite. Electron microscopy imaging showed that the palladium particles were well-dispersed within the polymer matrix and were typically 3-5 nm in diameter. The metal-polymer composite material was used as a catalyst for the coupling of phenylboronic acid with aryl halides in the presence of an inorganic base and showed excellent yield with high TOF values.