First Cross-Coupling Reaction of Potassium Aryltrifluoroborates with Organic Chlorides in Aqueous Media Catalyzed by an Oxime-Derived Palladacycle

Efficient Suzuki coupling over novel magnetic nanoparticle: Fe3O4/L-(+)-tartaric acid/Pd(0)

A new eco-friendly catalytic system is devised for C-C bond formation through Suzuki coupling, using an impressive nanocatalyst (Fe₃O₄/L-(+)-tartaric acid/Pd-NPs). It contains immobilized palladium (0) onto magnetite nanoparticles, stabilized by tartaric acid, and is characterized by FT-IR, XRD, EDS, SEM, TEM, TGA, and VSM. The catalyst is used in an efficient synthesis of biaryls in EtOH/H₂O (1:1), in the presence of K₂CO₃. Our Fe₃O₄/tartaric acid/Pd-NPs exhibit magnetic recoverability and reusability for five cycles without measurable loss of its activity.

trans-Dichlorobis(XPhos)palladium(II) Precatalyst for Suzuki-Miyaura Cross-Coupling Reactions of Aryl/Vinyl Sulfonates/Halides: Scope, Mechanistic Study, and Synthetic Applications

Suzuki-Miyaura cross-coupling reactions of aryl/vinyl sulfonates/halides with various boron species were performed using an easily available trans-dichlorobis(XPhos)palladium(II) precatalyst. Under microwave assistance, more than 30 coupling products were obtained with yields ranging from 23 to 99%, including the synthesis of two bioactive compounds, dubamine and tamoxifen. A mechanistic investigation of the Suzuki-Miyaura reaction was conducted notably by nuclear magnetic resonance (NMR) and high-resolution mass spectroscopy, revealing the nature of the active Pd⁰ species and of the reducing entity.

Desulfonylative Electrocarboxylation with Carbon Dioxide

Electrocarboxylation of organic halides is one of the most investigated electrochemical approaches for converting thermodynamically inert carbon dioxide (CO₂) into value-added carboxylic acids. By converting organic halides into their sulfone derivatives, we have developed a highly efficient electrochemical desulfonylative carboxylation protocol. Such a strategy takes advantage of CO₂ as the abundant C1 building block for the facile preparation of multifunctionalized carboxylic acids, including the nonsteroidal anti-inflammatory drug ibuprofen, under mild reaction conditions.

MIDA boronate allylation – synthesis of ibuprofen

MIDA boronates are among the most useful reagents for the Suzuki–Miyaura reaction. This chemistry typically generates new bonds between two aromatic rings, thereby restricting access to important areas of chemical space. Here we demonstrate the coupling of MIDA boronates to allylic electrophiles, including a new synthesis of the well-known COX inhibitor ibuprofen.

Here we demonstrate the coupling of MIDA boronates to allylic electrophiles, including a new synthesis of the well-known COX inhibitor ibuprofen.

Applications of sulfuryl fluoride (SO2F2) in chemical transformations

A number of novel methodologies concerning the chemical, biological and medicinal applications of sulfuryl fluoride (SO₂F₂) gas have dramatically improved year by year.

Faster and Greener Chemical Reaction Workup Using Silicone Elastomer-Coated Glass Powders

We have developed a substantially faster and greener technique for routine chemical reaction workups. We use silicone elastomer-coated glass powder ("FastWoRX") as an absorbent to extract organic products from a quenched aqueous reaction mixture. After filtration, FastWoRX powder loaded with organic products can serve as a convenient input for flash chromatographic separations. With this technique, tedious and solvent-consuming liquid-liquid extractions are replaced by a simple filtration. Use of FastWoRX reduces solvent use and the E-factor by up to an order of magnitude compared to traditional liquid-liquid extraction-based workup.

Deeper Insight into the Six-Step Domino Reaction of Aldehydes with Malononitrile and Evaluation of Antiviral and Antimalarial Activities of the Obtained Bicyclic Products

The straightforward and efficient synthesis of complex aza‐ and carbobicyclic compounds, which are of importance for medicinal chemistry, is a challenge for modern chemical methodology. An unprecedented metal‐free six‐step domino reaction of aldehydes with malononitrile was presented in our previous study to provide, in a single operation, these bicyclic nitrogen‐containing molecules. Presented here is a deeper investigation of this atom‐economical domino process by extending the scope of aldehydes, performing post‐modifications of domino products, applying bifunctional organocatalysts and comprehensive NMR studies of selected domino products. The thermodynamic aspects of the overall reaction are also demonstrated using DFT methods in conjunction with a semi‐empirical treatment of van der Waals interactions. Furthermore, biological studies of seven highly functionalized and artemisinin‐containing domino products against human cytomegalovirus (HCMV) and Plasmodium falciparum 3D7 are presented. Remarkably, in vitro tests against HCMV revealed five domino products to be highly active compounds (EC₅₀ 0.071–1.8 μm), outperforming the clinical reference drug ganciclovir (EC₅₀ 2.6 μm). Against P. falciparum 3D7, three of the investigated artemisinin‐derived domino products (EC₅₀ 0.72–1.8 nm) were more potent than the clinical drug chloroquine (EC₅₀ 9.1 nm).

Palladium-catalyzed direct C–H arylation of pyridine N-oxides with potassium aryl- and heteroaryltrifluoroborates

An efficient ligand-free Pd(OAc)₂-catalyzed selective arylation of pyridine N-oxides using potassium (hetero)aryltrifluoroborates as coupling partners via C–H bond activation was achieved in the presence of TBAI.

Diarylmethanes through an Unprecedented Palladium-Catalyzed C-C Cross-Coupling of 1-(Aryl)methoxy-1 H-Benzotriazoles with Arylboronic Acids

1-(Aryl)methoxy-1H-benzotriazoles (ArCH2OBt) are bench-stable reagents that are prepared readily from 1H-benzotriazol-1-yl-4-methylbenzenesulfonate (BtOTs) and benzylic alcohols. These compounds, which contain a N-O-C bond, undergo cross-coupling with arylboronic acids by C-O bond scission with catalysts that comprise Pd(OAc)2 and biarylphosphine ligands. Such reactivity of ArCH2OBt derivatives, leading to diarylmethanes, has not been described previously and constitutes a new activation of benzylic alcohols. With regard to the various ligands-metal complexes that support catalytic activity, it appears that those with smaller "percent buried volumes" (%Vbur) provide better outcomes. This factor has been evaluated in the initial optimization studies and in further reactions with difficult coupling partners. Ligand electronics of the biaryl moiety seem to play a lesser role in this type of reaction. The bis-coordinating bis[(2-diphenylphosphino)phenyl]ether appears to be suitable to improve the yields of low-yielding reactions.

Heck Reactions Catalyzed by Ultrasmall and Uniform Pd Nanoparticles Supported on Polyaniline

Using air as the oxidant instead of the traditionally employed persulfates, the smaller and more uniform Pd nanoparticles (around 2 nm) supported on polyaniline (Pd@PANI) can be easily fabricated by the oxidation-polymerization of aniline with PdCl2. This material is an efficient and environmentally friendly catalyst for Heck reactions due to its recyclability, low loading, and ligand-free and mild reaction conditions. It was even tolerant to sulfur-containing substrates. This work reports the Pd@PANI-catalyzed Heck reactions with very wide substrate scopes, and discloses the catalytic mechanisms based on experimental findings and results of catalyst analysis and characterization.

Iron catalysed Negishi cross-coupling using simple ethyl-monophosphines

Reported is a rare example of the use of monophosphines in iron catalysed Negishi cross-coupling. Substrate scope in terms of alkyl bromide and diaryl zinc reagent is explored.

Magnetic nanoparticles supported oxime palladacycle as a highly efficient and separable catalyst for room temperature Suzuki–Miyaura coupling reaction in aqueous media

Magnetic nanoparticles of Fe₃O₄ supported oxime palladacycle as a novel catalyst for room temperature Suzuki coupling reaction in aqueous media.

Suzuki–Miyaura reaction by heterogeneously supported Pd in water: recent studies

This review summarizes the progress made essentially in the last fifteen years in the Suzuki–Miyaura coupling reaction by heterogeneous palladium catalysis in water as the sole solvent.

Accessing 2-(hetero)arylmethyl-, -allyl-, and -propargyl-2,1-borazaronaphthalenes: palladium-catalyzed cross-couplings of 2-(chloromethyl)-2,1-borazaronaphthalenes

The synthesis of 2-(chloromethyl)-2,1-borazaronaphthalene has provided an opportunity to expand dramatically the functionalization of the azaborines. This azaborinyl building block can serve as the electrophile in palladium-catalyzed cross-coupling reactions to form sp(3)-sp and sp(3)-sp(2) bonds. The cross-coupling reactions of 2-(chloromethyl)-2,1-borazaronaphthalene with potassium (hetero)aryl- and alkenyltrifluoroborates as well as terminal alkynes provides access to a variety of novel azaborines, allowing a library of pseudobenzylic substituted azaborines to be prepared from one common starting material.

An emerging reactor technology for chemical synthesis: surface acoustic wave-assisted closed-vessel Suzuki coupling reactions

In this paper we demonstrate the use of an energy-efficient surface acoustic wave (SAW) device for driving closed-vessel SAW-assisted (CVSAW), ligand-free Suzuki couplings in aqueous media. The reactions were carried out on a mmolar scale with low to ultra-low catalyst loadings. The reactions were driven by heating resulting from the penetration of acoustic energy derived from RF Raleigh waves generated by a piezoelectric chip via a renewable fluid coupling layer. The yields were uniformly high and the reactions could be executed without added ligand and in water. In terms of energy density this new technology was determined to be roughly as efficient as microwaves and superior to ultrasound.

The palladium(ii) complex of N,N-diethyl-1-ferrocenyl-3-thiabutanamine: synthesis, solution and solid state structure and catalytic activity in Suzuki–Miyaura reaction

A novel phosphine-free ferrocene-containing Pd complex is an excellent precatalyst for Suzuki–Miyaura coupling.