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Two new palladium(II) catalysts, each containing a phenylthiazole ligand (2-methyl- (1a) and 2-amino-4-phenyl-1,3-thiazole (1b)), are prepared and characterized. The crystal structure of one, 2-methyl-4-phenyl)palladium(II) acetate (3a), is presented; it crystallizes as a dimer, with the ligand attached through the nitrogen on the thiazole and the ortho-carbon on the phenyl ring. The organometallic compounds can be used as catalysts in Suzuki–Miyaura aryl cross-coupling reactions. They are compatible with a wide range of functional groups, including carbonyls, amines, and phenols. [ABSTRACT FROM AUTHOR]

We have developed a highly efficient, ligand‐free Suzuki–Miyaura cross‐coupling protocol employing our lab‐prepared air and moisture‐stable Pd‐PEPPSI catalysts. The reaction of ethyl 2‐{4‐[(6‐chloroquinoxalin‐2‐yl)oxy]phenoxy}propionate (Assure) with various boronic acids afforded both traditional and decarbonylative coupling products in high yields. The catalyst's steric influence was assessed computationally using %Vbur calculations. The decarbonylative coupling pathway proved more efficient than the traditional Suzuki–Miyaura coupling under these conditions. Additionally, regioselectivity studies have been conducted on a variety of Assure analogues. This method excels in efficiency, requiring minimal catalyst, moderate temperatures, and rapid reaction completion. [ABSTRACT FROM AUTHOR]

A novel approach towards synthesizing new metalloid-substituted olefins has been accomplished by transforming (E)-1,2-diboryl-1-silylethenes through two consecutive Suzuki–Miyaura coupling reactions. This methodology provides an effective and selective way to obtain new, structurally different products, such as (E)-1-silyl-1-boryl-2-arylethens, (1E,3E)-1-silyl-1-boryl-2-alkenylethens, and (E)-1-silyl-1-aryl1-2-aryl2ethenes, which are difficult to synthesize through hydrometallation reactions and related processes. Due to the presence of reactive motifs (silyl group, Bpin moiety, and Csp2-H bond) in the structure of the final products, these molecules might be considered powerful building blocks in modern chemistry. With the aid of demetallation and cross-coupling reactions, they might be further functionalized into several invaluable chemicals, i.e., tetrasubstituted olefins (anti-cancer drugs, fluorescence materials), compounds with high π-conjugation, and polymers. [ABSTRACT FROM AUTHOR]

Ring systems of all sizes are frequent core or substructures in natural products and they are important elements of many drug molecules, as they often confer high binding affinity to and selectivity for disease‐relevant biological targets. A uniform key transformation in the synthesis of such structures is the cyclization step. Among the various approaches that have been developed for ring closure, the intramolecular Suzuki‐Miyaura reaction has emerged as a powerful option for the construction of normal‐ and medium‐sized rings as well as macrocycles, due to its stereospecificity, the mild reaction conditions, and the non‐toxic nature of the boron by‐products. In this review, we summarize the state‐of‐the‐art of the application of intramolecular Suzuki‐Miyaura cross‐coupling reactions in the construction of (macro)cyclic frameworks of natural products and bioactive molecules of synthetic origin, covering (mostly) examples that have been reported since 2015. Target molecules prepared via intramolecular Suzuki‐Miyaura cross‐coupling as a key step range from natural products/natural product analogs to synthetic drug candidates, featuring ring sizes from 4 to ≫12. We highlight the utility, scope, and limitations of the reaction for different ring sizes and arrays of functional groups. Where possible, comparisons with other methods of cyclization are provided. [ABSTRACT FROM AUTHOR]

Recent development in photocatalysis is increasingly focused on transforming organic compounds toward producing fine chemicals. Simple, non‐selective oxidation reactions (degradation of pollutants) and very demanding solar‐to‐chemical energy conversion processes (production of solar fuels) face severe economic limitations influenced by still low efficiency and insufficient stability of the systems. Synthesis of fine chemicals, including reductive and oxidative selective transformations, as well as C−C and C−N coupling reactions, can utilise the power of photocatalysis. Herein, we present the recent progress in photocatalytic systems designed to synthesise fine chemicals. In particular, we discuss the factors influencing the efficiency and selectivity of the organic transformations, dividing them into intrinsic (related to individual properties of photocatalysts) and extrinsic (originating from the reaction environment). A rational design of the photocatalytic systems, based on a deep understanding of these factors, opens new perspectives for applied photocatalysis. [ABSTRACT FROM AUTHOR]

A porous magnetic multifunctional copper-based metal-organic framework (MOF) was developed through combined covalent and dative post-synthetic modification (PSM) of the CuBDC. In this regard, a novel magnetic metal-organic framework (MMOF) consisting of supported 1,10-phenanthroline-2,9-dicarbaldehyde (Fe3O4@Cu(BDC)-NH2-PHD) has been fabricated by post-synthetic modifications of Fe3O4@Cu(BDC)-NH2. Subsequently, the prepared nanocomposites were modified using palladium chloride ions (Fe3O4@Cu(BDC)-NH2-PdPHD) to impart catalytic sites. As a result, the fabricated magnetic porous catalyst exhibited great catalytic activity in Suzuki-Miyaura cross-coupling reactions. Some of the essential advantages of the synthesized catalyst are; high catalytic activity, short reaction times, mild conditions, high thermal stability, and reusability. Moreover, his porous magnetic nanomaterial can be used as a new support to immobilize other metals in different catalytic reactions. [ABSTRACT FROM AUTHOR]

Regioselective C6‐arylation of thieno[3,2‐c]pyrazoles with aryl iodides as coupling partners has been developed. This strategy was performed in the presence of Pd(OAc)2 as catalyst in combination with AgOTf as an oxidant and TFA in dimethylacetamide. In all experiments, only the C6‐arylated thieno[3,2‐c]pyrazole was isolated since its C5‐regioisomer was not observed, indicating the high regioselectivity of this approach. The catalytic system used is compatible with a variety of 3‐functionalized thieno[3,2‐c]pyrazoles and iodoaryl electrophiles, providing access to 3,6‐disubstituted thieno[3,2‐c]pyrazoles in yields ranging from 49% to 94%. [ABSTRACT FROM AUTHOR]

This study presents an eco‐conscious approach to enhance the efficiency of the Suzuki–Miyaura cross‐coupling reaction. We first synthesized graphene oxide nanosheets using the Hummers method and then coated them to incorporate metallic copper on their surface. Following this, we conducted various analyses, including Fourier transform infrared spectroscopy (FT‐IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Brunauer–Emmett–Teller (BET) analysis, cyclic voltammetry (CV), and energy‐dispersive X‐ray spectroscopy (EDS) identification, to characterize these modified nanosheets. Subsequently, we utilized Cu‐modified graphene oxide nanosheets as cathode catalysts in an electro‐oxidation synthesis setup. To verify the effectiveness of this novel approach, we utilized bromobenzene and phenylboronic acid as model substrates to synthesize biphenyl compounds. The reaction yielded impressive product yields ranging from 87% to 93%. Operating under environmentally friendly conditions, this electro‐oxidation synthesis not only enhances selectivity but also significantly reduces the environmental impact of the reaction. Our findings highlight the potential of this green chemistry strategy, offering a promising avenue for sustainable and efficient organic synthesis, as evidenced by the successful coupling of bromobenzene and phenylboronic acid with consistently high yields. [ABSTRACT FROM AUTHOR]

In the present work, palladium nanoparticles embedded on banana leaves extract-modified graphitic carbon nitride [PdNPs@g-C3N4-BLE] was biogenically synthesized in a facile 3-step reaction in a clean and sustainable manner. In situ reduction of Pd(II) to Pd(0) was accomplished by the action of active phytochemicals present in the banana leaves extract as capping, reducing, and stabilizing agents. Therefore, the aforementioned synthesis of catalyst does not need toxic reagents, harsh conditions, and additional reductants. The structure and composition of the PdNPs@g-C3N4-BLE nanocatalyst were examined in detail through several spectroscopic and microscopic techniques. The PdNPs@g-C3N4-BLE nanocatalyst exhibited good catalytic activity in Suzuki–Miyaura cross-coupling and aryl halide cyanation reactions by giving high turnover numbers (TONs) and turnover frequencies (TOFs). The outstanding advantages of using the PdNPs@g-C3N4-BLE nanocatalyst are mild reaction conditions, short reaction time, heterogeneous nature, excellent yields, easy work-up procedure, and recyclability without any significant loss of catalytic activity. Additionally, the PdNPs@g-C3N4-BLE nanocatalyst showed remarkable antibacterial activity against gram-negative bacteria Escherichia coli and gram-positive bacteria Bacillus subtilis. [ABSTRACT FROM AUTHOR]

We prepared a highly ordered mesoporous polymer‐supported diarylphosphine ligand by simple substitution reaction. By utilizing this ligand, we successfully achieved the Suzuki‐Miyaura cross‐coupling of various aryl chlorides at room temperature with high yields. Also, we extended our investigation to the use of a macroporous polymer support in a similar way, which yielded effective Suzuki‐Miyaura cross‐coupling reactions of both aryl chlorides and hindered aryl bromides. [ABSTRACT FROM AUTHOR]

Phosphine periodic mesoporous organosilicas (R‐P‐PMO‐TMS: R=Ph, tBu), which possess electron‐donating alkyl substituents on the phosphorus atom, were synthesized using bifunctional compounds with alkoxysilyl‐ and phosphino groups, bis[3‐(triethoxysilyl)propyl]phenylphosphine borane (1 a) and bis[3‐(triethoxysilyl)propyl]‐tert‐butylphosphine borane (1 b). Immobilization of Pd(0) species was performed to give R‐P‐Pd‐PMO‐TMS: R=Ph (2 a), tBu (3 a), respectively. The Pd(0) immobilized 2 a and 3 a were applicable as catalysts for Suzuki‐Miyaura cross‐coupling reactions of aryl chlorides with phenylboronic acid. It was revealed that 3 a bearing more electron‐donating tBu groups exhibited higher catalytic activity. Various functional groups including both electron withdrawing and donating substituents were compatible in the system. The recyclability of 3 a was examined to support its moderate utility for the recycle use. [ABSTRACT FROM AUTHOR]

A new series of trifluoromethylated pyrimido[1,2-b]indazol-4(1H)-one derivatives was synthesized with good to excellent yields through a simple condensation of 3-aminoindazole derivatives with ethyl 4,4,4-trifluoro 3-oxobutanoate. The functionalization of the corresponding chlorinated fused tricyclic scaffolds via Suzuki-Miyaura and aromatic nucleophilic substitution reactions led to the synthesis of highly diverse trifluoromethylated pyrimido[1,2-b]indazole derivatives with good yields. [ABSTRACT FROM AUTHOR]

This article explores the use of nickel thiocyanate complexes as catalysts for cross-coupling reactions in organic synthesis. The authors investigate the synthesis of different (hetero)biaryls using these catalysts and highlight their potential applications in the production of biologically active compounds and electronic materials. The study also examines the impact of various phosphine ligands on the polymerization of thiophenes and phenylenes. The results demonstrate that the nickel thiocyanate complexes are effective catalysts for cross-coupling polymerization reactions. These complexes are stable and easy to prepare, making them suitable for various syntheses and polymerizations. [Extracted from the article]

Hybrid organic‐inorganic molecules have recently received great interest due to their unique properties, which give access to their implementation in biological and material sciences. Herein, a new synthetic approach for the direct‐linkage of the purely inorganic dodecaborate cluster to organic building blocks through B−C bond is established, using boronic acids as functional groups on the organic moiety, reacting under Suzuki–Miyaura coupling conditions with iodo‐undecahydridododecaborate. The choices of ligand (DavePhos) and solvent (N‐methylpyrrolidone for electron‐poor, CD3CN for electron‐rich groups) are essential for the successful coupling. Ultimately, the newly described methodology is found to be functional‐group tolerant covering a wide spectrum of substrates including electron‐poor arenes. [ABSTRACT FROM AUTHOR]

A scalable and environmentally benign protocol for a Suzuki–Miyaura cross‐coupling in water using vitamin E derived surfactant TPGS‐750‐M is reported. The protocol is the most simple and standard for such transformations under micellar catalysis that has been amply utilized within our own research and development portfolio over the last decade. The impact of the synthetic procedure is reenforced by green Process Mass Intensity and Total Carbon Release metrics. [ABSTRACT FROM AUTHOR]

A simplistic synthesis of (Z)-5-((substituted-2-(substituted phenyl)quinolin-3-yl)methylene)-2-thioxothiazolidin-4-one derivatives has been accomplished by employing acetic acid as the solvent and sodium acetate as the catalyst. We used the Suzuki-Miyaura cross coupling reaction to create carbon-carbon bonds. Our method is practical and has many benefits, such as a quicker reaction time and a higher yield under reflux conditions. For their anticancer and antibacterial activities, all produced compounds were described and tested. Compounds are some of these (IVa), (IVb), and (IVc) manifest significant antimicrobial activity. The compounds (IVe), (IVf), (IVg), and (IVh) show prominent antifungal activity. The compounds (IVi), (IVj), (IVk), and (IVl) against the breast cancer cell lines MCF-7 and MCF-10A, demonstrates strong anticancer activity. These findings imply that the rhodanine analogues might represent a fresh, potential model for anticancer and antibacterial medicines. [ABSTRACT FROM AUTHOR]

The C-3 modification of 1H-indazole has produced active pharmaceuticals for the treatment of cancer and HIV. But, so far, this transformation has seemed less available, due to the lack of efficient C-C bond formation at the less reactive C-3 position. In this work, a series of silica gel-supported PdO2 nanoparticles of 25–66 nm size were prepared by ball milling silica gel with divalent palladium precursors, and then employed as catalysts for the Suzuki–Miyaura cross-coupling of 1H-indazole derivative with phenylboronic acid. All the synthesized catalysts showed much higher cross-coupling yields than their palladium precursors, and could also be reused three times without losing high activity and selectivity in a toluene/water/ethanol mixed solvent. Although the palladium precursors showed an order of activity of PdCl2(dppf, 1,1′-bis(diphenylphosphino)ferrocene) > PdCl2(dtbpf, 1,1′-bis(di-tert-butylphosphino)ferrocene) > Pd(OAc, acetate)2, the synthesized catalysts showed an order of C1 (from Pd(OAc)2) > C3 (from PdCl2(dtbpf)) > C2 (from PdCl2(dppf)), which conformed to the orders of BET (Brunauer–Emmett–Teller) surface areas and acidities of these catalysts. Notably, the most inexpensive Pd(OAc)2 can be used as a palladium precursor for the synthesis of the best catalyst through simple ball milling. This work provides a highly active and inexpensive series of catalysts for C-3 modification of 1H-indazole, which are significant for the large-scale production of 1H-indazole-based pharmaceuticals. [ABSTRACT FROM AUTHOR]

The Suzuki–Miyaura cross‐coupling is one of the most important and powerful methods for constructing C−C bonds. However, the protodeboronation of arylboronic acids hinder the development of Suzuki–Miyaura coupling in the precise synthesis of conjugated polymers (CPs). Here, an anhydrous room temperature Suzuki–Miyaura cross‐coupling reaction between (hetero)aryl boronic esters and aryl sulfides was explored, of which universality was exemplified by thirty small molecules and twelve CPs. Meanwhile, the mechanistic studies involving with capturing four coordinated borate intermediate revealed the direct transmetalation of boronic esters in the absence of H2O suppressing the protodeboronation. Additionally, the room temperature reaction significantly reduced the homocoupling defects and enhanced the optoelectronic properties of the CPs. In all, this work provides a green protocol to synthesize alternating CPs. [ABSTRACT FROM AUTHOR]

The use of volatile solvents for organic synthesis is nowadays questioned due to their negative impact on the environnement. To develop sustainable and environmentally friendly methodologies, we propose to combine two green chemistry concepts: the use of bioinspired solvents: natural deep eutectic solvents (NaDES), and mechanochemistry. Using the Suzuki‐Miyaura coupling as a model reaction, we described an efficient mechanochemical method with NaDES as a LAG (liquid‐assisted grinding) additive with short reaction times and without any ligand or additional heating. A mechanochemical extraction was also used to reduce the amounts of extraction solvents and the total time of the synthesis process. [ABSTRACT FROM AUTHOR]

The Suzuki–Miyaura cross-coupling of pyridine-2-sulfonyl fluoride (PyFluor) with hetero(aryl) boronic acids and pinacol boronic esters is reported. The reactions can be performed using Pd(dppf)Cl2 as the catalyst, at temperatures between 65 and 100 °C and in the presence of water and oxygen. This transformation generates 2-arylpyridines in modest to good yields (5%–89%). [ABSTRACT FROM AUTHOR]

A tremendous research has been appeared on Pd-catalyzed Suzuki–Miyaura cross-coupling (SMC) during the last four decades due to its high prominence in constructing biaryl motifs of several complexes as well as simple organic compounds of high biological and commercial significance. The use of organic solid waste–derived materials for SMC in benign solvents like water/aqueous media is a very good achievement in these cases. We report in this article the usability of water extract of Tamarindus indica seeds ash (WETS) as a renewable base and reaction medium for Pd(OAc)2-catalyzed SMC reaction at room temperature (RT). The WETS has been characterized using powder XRD, EDAX, SEM, and FTIR analysis. Furthermore, this process is highly environmentally beneficial by the waste repurposing to prominent chemical transformation along with the advantages such as ambient condition and avoids non-renewable chemicals like volatile organic solvents, ligands, promoters, and bases. Based on these merits and the quick reactions with high yields of products, this method can attain the interest of the scientific community in exploring the waste-derived ashes to significant chemical transformations. Tamarindus indica seed ash extract for C–C coupling under added organics and volatile organic solvent-free conditions: a waste repurposing technique for Suzuki–Miyaura reaction [ABSTRACT FROM AUTHOR]

Comprehensive Summary: The structures assigned to all four members, 1—4, of the recently reported favolasin class of natural product have been prepared for the first time by chemical synthesis. Suzuki‐Miyaura cross‐coupling chemistry was used to establish the associated biaryl substructures. The key step used in preparing the 1,5‐benzodioxepin ring system associated with compounds 3 and 4 was the acid‐catalyzed 7‐exo‐tet cyclization of an appropriately substituted 2‐(oxiran‐2‐ylmethoxy)phenol while a base‐promoted 6‐exo‐tet cyclization of the same substrate was used to construct the 2,3‐dihydrobenzo[b][1,4]dioxine core of target 2. The spectral data derived from the four synthetically‐produced favolasins matched those reported for the corresponding natural products. Preliminary biological screening of compounds 1—3 as well as a suite of fourteen precursors reveal that they display no notable anti‐bacterial, anti‐fungal or anti‐tumor activities but congener K (4) is active, in the mM range, against Plasmodium falciparum. [ABSTRACT FROM AUTHOR]

The Pd‐catalyzed Suzuki‐Miyaura cross‐couplings (SMRs) are utilized as the most practical method to construct C−C bond, especial for biaryls. However, a major disadvantage of current protocols is the requirement of excess organoboron coupling partner (1.5–3.0 equiv.). Herein, a novel palladacyclic 1,3‐bis(2,6‐diisopropylphenyl)acenaphthoimidazol‐2‐ylidene (AnIPr) precatalyst possessing a chiral oxazoline was designed, which enabled a general protocol towards bulky tri‐ortho‐substituted biaryls, ternaphthalenes and diarylanthracenes via the Pd‐catalyzed SMR employing equimolar organoborons and aryl bromides. A remarkable scope of substrates with various functional groups and heterocycles were well compatible with an adaptability to synthesize useful ligands. [ABSTRACT FROM AUTHOR]

The excellent catalytic activities of abnormal NHC carbene complexes, where the C2 position remains unaffected, and coordination occurs at the C4 or C5 position of the imidazolium ring, is still a fascinating but scarce area of research. This present work reports a palladium complex (LPdBr) bearing abnormal NHC with CNN pincer architecture. It is synthesized from imidazolium‐based quinoline ligand (LH) with Pd(OAc)2 via ‐NH and carbene deprotonation. The complex was fully characterized by NMR spectroscopy (1D and 2D) and high‐resolution mass spectrometry (HRMS). The structure and abnormal coordination modes of the complex are further confirmed with the help of single‐crystal X‐ray diffraction. The studies revealed the abnormal coordination mode in LPdBr where C5 carbon of the imidazolium ring participates in bonding, leaving the C2 position unaffected. The catalytic potential of complex LPdBr was investigated in the Pd‐catalyzed Suzuki‐Miyaura coupling of various aryl/heteroaryl chlorides with different aryl/naphthyl/phenanthryl boronic acids. The catalyst LPdBr successfully activated various less‐activated aryl chloride substrates. LPdBr also exhibited good catalytic activity at 1 mol% Pd loading under microwave irradiation and in green solvent water. The mechanism of the catalytic cycle is investigated and proposed by HRMS. [ABSTRACT FROM AUTHOR]

This study depicts the novel synthesis of sustainable, cost‐effective, and environmentally friendly Schiff base‐Pd nanomagnetic heterogeneous catalyst (MNP‐AF‐Pd) decorated on superparamagnetic Fe3O4@SiO2 core‐shell magnetic nanoparticles. The synthesized MNP‐AF‐Pd catalyst were characterized by thermogravimetric analysis (TGA), Fourier transform infrared (FT‐IR), X‐ray diffraction (XRD), X‐ray photoelectron spectroscopy (XPS), inductively coupled plasma‐optical emission spectrometry (ICP‐OES) analysis, Brunauer–Emmett–Teller (BET), energy dispersive X‐ray analysis (EDX), vibrating‐sample magnetometer (VSM), field‐emission scanning electron microscopy (FE‐SEM), and high‐resolution transmission electron microscopy (HR‐TEM). The synthesized MNP‐AF‐Pd catalyst was shown to be an effective catalyst for Suzuki–Miyaura cross‐coupling reaction of several aryl boronic acid and degradation of hazardous organic dyes, particularly rhodamine B and methylene blue under mild reaction conditions. The catalyst is simply retrieved, recovered, and repeatedly utilized for several cycles without appreciably diminishing catalytic activity. [ABSTRACT FROM AUTHOR]

A convenient multistep synthetic methodology to afford prospective push‐pull fluorophores based on the N(2)‐fluoroaryl‐1,2,3‐triazole scaffold as valuable functional blocks in the design of blue‐emitting organic materials is reported. The strategy includes five synthetic steps with yields of 60–99% at each stage. The obtained photoactive molecules, 2‐fluoroaryl‐5‐aryl‐4‐methyl‐1,2,3‐triazoles, were found to possess a blue‐violet emission in the range of λ=330–440 nm and the absolute quantum yield of >99% in solvents of different polarities. The electron transfer mechanistic features in the excited states for the developed N(2)‐fluoroaryl‐1,2,3‐triazoles compared to the 1,2,3‐triazoles‐1‐oxide analogues were also studied by using DFT and CIS calculations. [ABSTRACT FROM AUTHOR]

A scalable and environmentally benign route to the free base of branaplam, a small molecule splicing modulator, was identified and developed. This alternative approach circumvented the inherent risk of dioxin formation associated with ortho‐halo phenol derivatives present in the previous route. A Friedel–Crafts approach provided a reliable access to the key intermediate, subsequently followed by a Suzuki–Miyaura cross‐coupling. Multiple process aspects of the synthetic approach were evaluated, and a robust process for its large‐scale synthesis was developed and successfully demonstrated. [ABSTRACT FROM AUTHOR]

Suzuki-Miyaura cross-coupling reaction by homogeneous Pd complex is a powerful route to construct carbon-carbon bond and is now widely applied in the synthesis of functional organic compounds. Heterogeneous Pd catalysts are highly desired as alternatives to homogeneous ones due to their facile reusability and good compatibility. Herein, zeolite-encaged Pd particles, namely Pd@MFI, have been successfully prepared via an in-situ hydrothermal strategy and investigated as promising heterogeneous catalysts for Suzuki-Miyaura cross-coupling reactions. Characterization results demonstrate that high dispersed Pd particles with apparent sizes of 1–2 nm have been encaged in and efficiently stabilized by the matrix of MFI zeolite. The as-prepared Pd@MFI catalysts are active in the Suzuki-Miyaura coupling reaction between bromobenzene and phenylboronic acid, and the presence of basic sites adjacent to Pd sites are crucial to achieving high catalytic activity via effective cooperation. Pd@K-ZSM-5 can be optimized for the coupling between bromobenzene and phenylboronic acid and can catalyze the reaction with a low apparent activation energy value of 41.2 kJ/mol. Pd@K-ZSM-5 also shows good stability and can be recycled for at least five times without obvious loss in activity, demonstrating its great potential as a heterogeneous catalyst for Suzuki-Miyaura cross-coupling reactions. Encapsulation of metal species in zeolite matrix offers a big opportunity to the heterogenization of homogeneous metal catalysts for practical chemical transformations. [Display omitted] • Zeolite-encaged palladium catalysts constructed for heterogeneous Suzuki-Miyaura cross-coupling reactions. • High catalytic activity and good stability achieved with Pd@K-ZSM-5 catalysts. • Structural confinement promoting the catalytic reactions within zeolite channels. [ABSTRACT FROM AUTHOR]

The enantiomerically pure ligand BisNap-Phos was obtained in a straightforward sequence of reactions beginning with inexpensive starting materials under the readily affordable conditions in high overall yield. An asymmetric BisNap-Phos-palladium complex-catalyzed Suzuki–Miyaura coupling leading to axially chiral biaryl compounds was described. The reactions were carried out under mild conditions in aqueous and organic media. A series of atropisomeric biaryls were synthesized with excellent yields and high enantioselectivities (up to 86% ee). The methodology provides an efficient and practical strategy for the synthesis of novel multifunctionalized axially chiral biaryl compounds under mild environmentally friendly and easily affordable conditions. [ABSTRACT FROM AUTHOR]

The production of sustainable catalytic supports for palladium nanoparticles is always desired, even more so through the recovery of biomass residues. In this sense, two different solids were investigated — chitosan/cellulose film and corn stem biochar — as catalytic supports of palladium nanoparticles. The solids were carefully characterized and tested in the Suzuki-Miyaura reaction, a typical cross-coupling reaction. The developed catalytic systems proved to be efficient and sustainable, promoted the formation of target products very well, and demanded green reactants under environmentally appropriate conditions. With the results shown in the manuscript, it is expected to contribute to the valorization of biomass and agro-industrial residues in the development of new catalysts for the chemical industry. [ABSTRACT FROM AUTHOR]

The paper describes the synthesis of a novel nano-sized phosphine-free benzothiazole-based palladium(II) complexes from easily accessible starting materials and study their efficiency as catalysts for Suzuki Miyaura cross coupling reaction using water as a solvent under microwaves irradiations. Structural elucidation of the novel nano-sized benzthiazole-based complexes was achieved by analytical and physical characterization tools. The catalytic activity of the novel nanocatalysts was invetigated for SMC of aryl halides with arylboronic acids using water as a solvent and under microwaves irradiation conditions as green mild reaction conditions. [ABSTRACT FROM AUTHOR]

This manuscript reports the valorization of sewage sludge with the production of activated carbon. Thus, a series of 11 adsorbents are produced, activated with different substances (salt, acid, and base), and their adsorptive properties are carefully evaluated. The C6 series of activated carbons prove to be very efficient for removing nitrate anions from aqueous medium and, due to this, it is evaluated as a catalytic support for palladium nanoparticles. The generated solid, named Pd@CA6F, is the first report of a catalyst containing activated carbon from sewage sludge that is efficient in the Suzuki‐Miyaura cross‐coupling. The catalytic system developed is eco‐friendly, phosphine‐free, and of low cost. Good yields are obtained in the coupling of aryl iodides with phenylboronic acid in a short time. The same catalyst load could be recycled for up to ten times. [ABSTRACT FROM AUTHOR]

A new series of trifluoromethylated pyrimido[1,2-b]indazol-4(1H)-one derivatives was synthesized with good to excellent yields through a simple condensation of 3-aminoindazole derivatives with ethyl 4,4,4-trifluoro 3-oxobutanoate. The functionalization of the corresponding chlorinated fused tricyclic scaffolds via Suzuki-Miyaura and aromatic nucleophilic substitution reactions led to the synthesis of highly diverse trifluoromethylated pyrimido[1,2-b]indazole derivatives with good yields.

The C-3 modification of 1H-indazole has produced active pharmaceuticals for the treatment of cancer and HIV. But, so far, this transformation has seemed less available, due to the lack of efficient C-C bond formation at the less reactive C-3 position. In this work, a series of silica gel-supported PdO2 nanoparticles of 25–66 nm size were prepared by ball milling silica gel with divalent palladium precursors, and then employed as catalysts for the Suzuki–Miyaura cross-coupling of 1H-indazole derivative with phenylboronic acid. All the synthesized catalysts showed much higher cross-coupling yields than their palladium precursors, and could also be reused three times without losing high activity and selectivity in a toluene/water/ethanol mixed solvent. Although the palladium precursors showed an order of activity of PdCl2(dppf, 1,1′-bis(diphenylphosphino)ferrocene) > PdCl2(dtbpf, 1,1′-bis(di-tert-butylphosphino)ferrocene) > Pd(OAc, acetate)2, the synthesized catalysts showed an order of C1 (from Pd(OAc)2) > C3 (from PdCl2(dtbpf)) > C2 (from PdCl2(dppf)), which conformed to the orders of BET (Brunauer–Emmett–Teller) surface areas and acidities of these catalysts. Notably, the most inexpensive Pd(OAc)2 can be used as a palladium precursor for the synthesis of the best catalyst through simple ball milling. This work provides a highly active and inexpensive series of catalysts for C-3 modification of 1H-indazole, which are significant for the large-scale production of 1H-indazole-based pharmaceuticals.

The synthesis of a palladium complex bearing two diethyl[(5-phenyl-1,3,4-oxadiazol-2-ylamino)(4-nitrophenyl)methyl]phosphonates as ligands has demonstrated the ability of this type of $\alpha $-aminophosphonates to coordinate to the palladium(II) ion via their electronically enriched nitrogen atom of the 1,3,4-oxadiazole ring. The complex was fully characterized by elemental analysis, infrared, NMR and mass spectrometry. A solid-state structure revealed the trans coordination of the two nitrogenated ligands. The presence of a hemilabile P(O)(OEt)$_{2}$ moiety in the $\alpha $-aminophosphonates was exploited into palladium-catalyzed Suzuki–Miyaura cross-coupling of aryl halides. The formation of ($N{,}O$)-chelate intermediates may increase the steric hindrance and the electronic density of the metal, which should favor the oxidative addition and the reductive elimination/product decoordination elementary steps. With our catalytic systems, good activities for the formation of ortho-di/trisubstituted biphenyl compounds were observed from aryl bromides using only 0.5 mol% of palladium. Cross-coupling of aryl chlorides required a catalyst loading of 1 mol% to generate ortho-substituted biphenyls.

The development of peptide stapling techniques to stabilise α-helical secondary structure motifs of peptides led to the design of modulators of protein–protein interactions, which had been considered undruggable for a long time. We disclose a novel approach towards peptide stapling utilising macrocyclisation by late-stage Suzuki–Miyaura cross-coupling of bromotryptophan-containing peptides of the catenin-binding domain of axin. Optimisation of the linker length in order to find a compromise between both sufficient linker rigidity and flexibility resulted in a peptide with an increased α-helicity and enhanced binding affinity to its native binding partner β-catenin. An increased proteolytic stability against proteinase K has been demonstrated.

Ni nanoparticles (NiNPs) were prepared by thermal decomposition of nickel acetylacetonate in the presence of a third generation polypyridylphenylene dendrimer (G3) which acts both as a coordinating ligand due to presence of pyridine groups and as a stabilizing agent due to highly branched architecture. Transmission electron microscopy (TEM), high resolution transmission electron microscopy (HRTEM), and X‐ray photoelectron spectroscopy (XPS) were used to extensively evaluate structure and morphology of the synthesized NiNPs@G3. The selected area electron diffraction (SAED) allowed us to conclude about fcc structure of NiNPs while STEM EDS analysis demonstrated a formation of core‐shell NiO@Ni NPs. Further, the catalyst was tested in selected Suzuki‐Miyaura cross‐coupling reactions at mild conditions and demonstrated a high efficiency at low Ni loading with negligible content of Ni0 on the NP surface. The functional hyperbranched dendrimer macromolecule provided an excellent stabilization for NiNPs@G3 while allowing an easy access for reactants to catalytic sites. The high activity of the catalyst in the recycling experiments was maintained by the absence of Ni leaching from the NiNPs@G3. [ABSTRACT FROM AUTHOR]

Heat-up and hot-injection methods were employed to synthesize Ni nanoparticles (NPs) with narrow size distribution in the presence of hyperbranched pyridylphenylene polymer (PPP) as a stabilizing agent. It was shown that depending on the synthetic method, Ni NPs were formed either in a cross-linked polymer network or stabilized by a soluble hyperbranched polymer. Ni NPs were characterized by a combination of transmission electron microscopy (TEM), scanning TEM, thermogravimetric analysis, powder X-ray diffraction, X-ray photoelectron spectroscopy, energy dispersive X-ray analysis, and magnetic measurements. The architecture of polymer support was found to significantly effect Ni NPs characteristics and behavior. The Ni NPs demonstrated a high catalytic activity in a model Suzuki–Miyaura cross-coupling reaction. No significant drop in activity was observed upon repeated use after magnetic separation in five consecutive catalytic cycles. We believe that hyperbranched PPP can serve as universal platform for the controllable synthesis of Ni NPs, acting as highly active and stable catalysts. [ABSTRACT FROM AUTHOR]

Aim: Silent information regulator two homologue one (SIRT1) is an emerging target for managing metabolic disorders. This study aimed to synthesize novel 5-(- substituted phenyl)-2-aryl benzimidazole derivatives and evaluate them for SIRT1 activation., Methods: The compounds were designed according to the findings of the QSAR models framed in our previous studies. Molecular docking and dynamics studies were also performed to explore the interactions of designed compounds with the active site of the SIRT1 enzyme using AutoDock Vina and Schrödinger Maestro version 11.8.012, respectively. Compounds with good binding affinity were synthesized by Suzuki-Miyaura cross-coupling and spectrally characterized. The molecules were evaluated for their in vitro SIRT1 activation properties using a fluorescent screening kit. Based on the results of in vitro assay, a structure-activity relationship was established. SwissADME was employed to calculate the pharmacokinetics characteristics of the synthesized molecules., Results: The molecular docking studies revealed that all the activators were effectively docked in the catalytic active site. All compounds demonstrated interactions with important amino acids like Glu230 and Arg446. In molecular dynamics simulations, the root mean square deviation (RMSD) of compound 5m and protein SIRT1 remained stable, i.e., below 3mm. Compound 5m, 4-(2-(3,4-dihydroxy-5-nitrophenyl)-1H-benzo[d]imidazol- 5-yl)benzaldehyde, was the most potent compound with an EC50 value of 0.006 mM (±0.001) and maximum activation of 240.5%. All the synthesized compounds had acceptable theoretical ADME profiles, and drug-likeness properties complied with Lipinski's rule., Conclusion: According to the findings, synthesized compounds may be viable leads for SIRT1 activators and may be used to advance preclinical in vivo research utilizing animal models., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.net.)

A series of 1H-1,2,3-triazole analogs (7a–7d and 9a–9s) were synthesized via “click” chemistry and evaluated for in vitro carbonic anhydrase-II (bovine and human) inhibitory activity. The synthesis of intermediates, 7a and 7c, was achieved by using (S)-(-)ethyl lactate as a starting material. These compounds (7a and 7c) underwent Suzuki–Miyaura cross-coupling reaction with different arylboronic acids in 1,4-dioxane, reflux at 90–120°C for 8 h using Pd(PPh3)4 as a catalyst (5 mol%), and K2CO3 (3.0 equiv)/K2PO4 (3.0 equiv) as a base to produce target 1H-1,2,3-triazole molecules (9a–9s) for a good yield of 67–86%. All the synthesized compounds were characterized through NMR spectroscopic techniques. Furthermore, all those compounds have shown significant inhibitory potential for both sources of carbonic anhydrase-II (CA-II). In the case of bCA-II, compounds 9i, 7d, 9h, 9o, 9g, and 9e showed potent activity with IC50 values in the range of 11.1–17.8 µM. Whereas for hCA-II, compounds 9i, 9c, 9o, and 9j showed great potential with IC50 values in the range of 10.9–18.5 µM. The preliminary structure–activity relationship indicates that the presence of the 1H-1,2,3-triazole moiety in those synthesized 1H-1,2,3-triazole analogs (7a–7d and 9a–9s) significantly contributes to the overall activity. However, several substitutions on this scaffold affect the activity to several folds. The selectivity index showed that compounds 9c, 9k, and 9p are selective inhibitors of hCA-II. Kinetics studies showed that these compounds inhibited both enzymes (bCA-II and hCA-II) in a competitive manner. Molecular docking indicates that all the active compounds fit well in the active site of CA-II. This study has explored the role of 1H-1,2,3-triazole-containing compounds in the inhibition of CA-II to combat CA-II-related disorders.

A novel phosphine-free pyrimidine-based palladium(II) complex have been synthesized from easily accessible starting materials and its ability to be a catalyst for cross-coupling reactions namely, Suzuki-Miyaura (SMC) has been investigated. The structure of the new formamidinyl pyrimidine-based complex has been elucidated by using spectroscopic as well as physical characterization techniques. The novel palladium(II) complex showed its applicability as a catalyst for SMC of 2-bromothiophene and 2,5-dibromothiophene with arylboronic acids under conventional and microwaves irradiation conditions. The developed catalytic system exhibited reasonable catalytic activity to obtain 2-aryl and 2,5-diarylthiophene derivatives using mild reaction conditions. [ABSTRACT FROM AUTHOR]

Abstract Discovering efficient methods for the formation of carbon‐carbon bonds is a central ongoing theme in organic synthesis. Cross‐coupling reactions catalysed by metal nanoparticles are attractive alternatives to the traditional use of metal counterparts due to the catalytic tunability, selectivity, recyclability and reusability of the nanoparticles. The ongoing search for sustainable processes demands that reusable and environmentally benign catalysts are used. While the advantages of nanoparticles catalysts over bulk catalysts cannot be overemphasised, the problem of sintering, agglomeration and leaching are drawbacks to their full industrial applications. Hence, efforts are being made towards advancing the efficiency of the catalytic nanoparticle systems over the years. This review presents the progress, the challenges and the prospects of palladium nanoparticle with focus on Heck, Suzuki, Hiyama and Sonogashira cross‐coupling reactions involving (hetero) aryl halides and the analogues.

An amide functionlized bidentate NHC-Pd complex was successfully prepared by a facile solvothermal methodology from a bridged bis-benzimidazolium chloride and K 2 PdCl 4. The new bidentate NHC-Pd complex has been effectively applied as catalyst in Suzuki-Miyaura cross-coupling reactions of aryl halides with arylboronic acids in neat water (yields up to 99.0%). [Display omitted] • A novel bidentate Pd-NHC complex has been synthesized. • The new bidentate Pd-NHC complex showed good activity for Suzuki coupling reaction. • Water was selected as the solvent for Suzuki-Miyaura cross-coupling. • The functional ligand Pd complex is distinctly influenced by the electronic and steric effects on the catalytic process. An amide functionlized bidentate NHC-Pd complex was successfully prepared by a facile solvothermal methodology from a bridged bis-benzimidazolium chloride and K 2 PdCl 4. The new bidentate NHC-Pd complex has been effectively applied as catalyst in Suzuki-Miyaura cross-coupling reactions of aryl halides with arylboronic acids in distilled water (yields up to 99.0%). The bridged bis-benzimidazolium ligand from the Pd complex, bearing the amide functional groups on the nitrogen atom, showed to distinctly influence the electronic and steric effects on the catalytic process. The potential of application of the new NHC-Pd catalyst in diverse C C bond forming processes, working under environmentally friendly conditions, is further outlined. [ABSTRACT FROM AUTHOR]

The core‐shell magnetic mesoporous microspheres immobilized NHC‐palladacycles (NHC=N‐heterocyclic carbene) catalyst with constrained aliphatic linker group (Fe3O4@mSiO2@NHC−Pd) were readily prepared by the well‐designed method, which showed higher palladium loading (0.20 mmol g−1) and higher catalytic activity than the non‐mesoporous catalysts (Fe3O4@SiO2@NHC−Pd) prepared by the same process in the Suzuki‐Miyaura cross‐coupling reactions of aryl chlorides and aryl boronic acids. Herein, Fe3O4@mSiO2@NHC−Pd could be used 12 times without significant activity loss, and no palladium leakage was detected in both the product and catalytic residue, highlighting the efficiency of our strategy for immobilizing the catalyst. Remarkably, this approach allows the synthesis of important drug intermediates 2‐aryl‐4‐aminoquinazolines and o‐tolylbenzonitrile (OTBN). [ABSTRACT FROM AUTHOR]

Although cross‐coupling reactions of amides by selective N−C cleavage are one of the most powerful and burgeoning areas in organic synthesis due to the ubiquity of amide bonds, the development of mechanochemical, solid‐state methods remains a major challenge. Herein, we report the first mechanochemical strategy for highly chemoselective, solvent‐free palladium‐catalyzed cross‐coupling of amides by N−C bond activation. The method is conducted in the absence of external heating, for short reaction time and shows excellent chemoselectivity for σ N−C bond activation. The reaction shows excellent functional group tolerance and can be applied to late‐stage functionalization of complex APIs and sequential orthogonal cross‐couplings exploiting double solventless solid‐state methods. The results extend mechanochemical reaction environments to advance the chemical repertoire of N−C bond interconversions to solid‐state environmentally friendly mechanochemical methods. [ABSTRACT FROM AUTHOR]

A facile and environmentally benign access to N -aryl/alkyl-4 H -benzoxazin-2-amines is achieved from 1-[2-(hydroxymethyl)phenyl/alkyl]-3-phenylthioureas under transition-metal-free conditions. The conversions occur smoothly in the presence of a catalytic amount of molecular iodine and hydrogen peroxide as the oxidant in tetrahydrofuran at room temperature to afford moderate to good yields (28–90%) of the desired products within 2 hours. This method reports the first examples of the catalytic transformations of 1-[2-(hydroxymethyl)phenyl/alkyl]-3-phenylthioureas into N -aryl/alkyl-4 H -benzoxazin-2-amines based on desulfurative cyclization. [ABSTRACT FROM AUTHOR]