Highly efficient heterogeneous copper-catalyzed decarboxylative cross-coupling of potassium polyfluorobenzoates with aryl halides leading to polyfluorobiaryls

Lin Y., Cai M., Fang Z., Zhao H.

A practical method for the synthesis of aryl alkyl ethers has been developed by heterogeneous Cu-catalyzed C–O coupling.

Hao W., Liu H., Yin L., Cai M.

A novel and highly efficient heterogeneous palladium-catalyzed carbonylative cross-coupling of aryl iodides with triarylbismuths has been developed that proceeds smoothly at atmospheric CO pressure and provides a general and powerful tool for the preparation of various valuable biaryl ketones with high atom economy, good to excellent yield, and recyclability of the catalyst. The reaction is the first example of Pd-catalyzed carbonylative cross-coupling for the construction of biaryl ketones using triarylbismuths as substrates.

Zhao H., He W., Wei L., Cai M.

A highly efficient heterogeneous copper-catalyzed three-component coupling of tetrahydroisoquinolines, aldehydes and 1-alkynes has been described.

Havasi F., Ghorbani-Choghamarani A., Nikpour F.

The preparation of phenols and anilines from aryl halides in the presence of MCM-41-dtz-Pd as a heterogeneous nanocatalyst has been introduced.

Sardzinski L.W., Wertjes W.C., Schnaith A.M., Kalyani D.

A Ni-catalyzed method for the coupling of perfluorobenzoates with aryl halides and pseudohalides is described. Aryl iodides, bromides, chlorides, triflates, and tosylates participate in these transformations to afford the products in good yields. Penta-, tetra-, and trifluorinated biaryl compounds are obtained using these newly developed Ni-catalyzed decarboxylative cross-coupling reactions.

Zhao H., Jiang Y., Chen Q., Cai M.

A heterogeneous copper-catalyzed cross-coupling reaction of diaryl diselenides with organoboronic acids for the synthesis of diorganyl selenides has been described.

Fu Z., Xiong Q., Zhang W., Li Z., Cai H.

A Pd-catalyzed direct arylation of electron-deficient polyfluoroarenes with readily available aryliodine(III) diacetates was developed with moderate to good yields. The process exhibited good functional tolerance with respect to methyl, methoxy, bromo, chloro, trifluoromethyl, cyano, and aldehyde groups. Mechanistic studies revealed this coupling involved in situ generation of aryl iodide from heating-promoted decomposition of aryliodine(III) diacetate, followed by coupling with polyfluoroarenes substrates to afford the desired products.

Cai M., Yao R., Chen L., Zhao H.

The carbon–sulfur coupling reaction of aryl halides with thioacetamide using an MCM-41-immobilized bidentate nitrogen copper(I) complex [MCM-41-2N-CuI] as an efficient heterogeneous catalyst is described. Developed catalytic system is found to be effective for the coupling reaction of aryl halides with thioacetamide providing moderate to high yield of diaryl sulfides. This heterogeneous copper catalyst exhibits higher activity than CuI and can be recovered by a simple filtration of the reaction solution and reused for at least 10 consecutive trials without any decreases in activity.

Zhao H., He W., Yao R., Cai M.

The heterogeneous cascade three-component reaction of amines, carbon disulfide (CS2) and 2-iodoanilines was achieved in dimethylformamide (DMF) at 110 °C in the presence of 10 mol% of 3-(2-aminoethylamino)propyl-functionalized MCM-41-immobilized copper complex [MCM-41-2N-CuCl] using potassium carbonate (K2CO3) as base, yielding a variety of 2-aminobenzothiazoles in good to excellent yields. This heterogeneous copper catalyst influences the selectivity of the reaction and can be recovered and recycled by a simple filtration of the reaction solution and used for at least 10 consecutive trials without any decreases in activity.

Fan H., Shang Y., Su W.

The palladium-catalyzed direct arylation of polyfluoroarenes with organosilicon reagents was achieved by establishing general reaction conditions. This protocol was compatible with a broad range of functional groups and offered the desired products in moderate to good yields.

Zhang L., Li P., Liu C., Yang J., Wang M., Wang L.

An efficient and reusable Fe3O4-nanoparticle-immobilized-palladium catalyst was prepared and applied to the direct C-2 arylation of indoles with arylboronic acids.

Senaweera S.M., Singh A., Weaver J.D.

Polyfluorinated aromatics are essential to materials science as well as the pharmaceutical and agrochemical industries and yet are often difficult to access. This Communication describes a photocatalytic hydrodefluorination approach which begins with easily accessible perfluoroarenes and selectively reduces the C-F bonds. The method allows facile access to a number of partially fluorinated arenes and takes place with unprecedented catalytic activity using a safe and inexpensive amine as the reductant.

Xiao R., Zhao H., Cai M.

The heterogeneous N-arylation reaction of indoles with aryl halides was achieved in toluene at 110 °C by using 4 mol % MCM-41-immobilized bidentate nitrogen copper(I) complex [MCM-41–2N-CuI] as catalyst and K 3 PO 4 as base, yielding a variety of N -arylindoles in good to excellent yields. The heterogeneous copper catalyst exhibited as high activity as homogeneous CuI/diamine catalytic system and can be easily prepared by a simple two-step procedure from commercially available and cheap reagents and recovered by a simple filtration of the reaction solution and reused for 10 cycles with almost consistent activity.

Zhu X., Li F., Su W.

A novel cross-coupling reaction of arenediazonium tetrafluoroborates with polyfluoroarenes is briefly described. It has advantages of high reaction efficiency, excellent functional group compatibility, mild reaction conditions, short reaction time, and inexpensive ligand. This reaction also can be performed as a one-pot process from anilines omitting isolation of arenediazonium tetrafluoroborates. It has been extended to the preparation of biaryls containing polyfluoroarene structural moiety.

Gooßen L.J., Gooßen K.

Transition metal-catalyzed decarboxylative couplings have recently emerged as a promising concept for C–C and C–heteroatom bond formation. Our contribution to this rapidly evolving field was the development of redox-neutral decarboxylative cross-couplings. In these catalytic transformations, carboxylic acids extrude CO2 to give organometallic intermediates, which react with aryl electrophiles under regioselective formation of a new C–C bond. This reaction concept compares favorably to traditional cross-couplings involving preformed organometallic reagents, as it draws on stable and broadly available carboxylic acids as the source of carbon nucleophiles. In this chapter, we describe the invention process that resulted in the discovery of the first active catalyst systems and in the stepwise extension of this concept to a broadly applicable synthetic concept. A short overview on recent developments in this field is also provided.

Debnath S., Bera P., Mirza Y.K., Bhatt S., Pandey A.K., Jana P., Saha B., Bera M.

AbstractTransition metal catalyzed decarboxylative cross‐coupling reactions that generate C–C bonds and C−heteroatom bonds have become useful methods to synthesize several value‐added organic molecules. Decarboxylative cross‐couplings establish profitable replacements to conventional cross‐coupling or addition reactions involving organometallic reagents. The key factor in the extensive implementation of these methods has been the endured development of consistent and flexible transition metal catalysts that function under operationally simple, user‐friendly conditions. This review focuses on recent advances (from 2015 to till date) and discoveries on these reactions with interest on the mechanistic aspects of the reactions.

Shchegol'kov Evgeny V., Burgart Yanina V., Shchur Irina V., Saloutin Victor I.

Polyfluoroaromatic compounds occupy a special place in organic synthesis due to a wide range of their chemical transformations and unique biological properties. The introduction of the carboxyl function into polyfluoroarenes allows further diversification of the chemistry of these compounds. This review summarizes data on the chemical transformations of polyfluorobenzoic acids, including derivatives of polyfluorosalicylic acids. The reactions of esterification, amidation, reduction, decarboxylation, metal-catalyzed decarboxylative cross-coupling, C–H functionalization, reductive defluorination, nucleophilic aromatic substitution, heterocyclization and complex formation are considered. Reactivity features of polyfluorobenzoates in comparison to their non-fluorinated counterparts are highlighted. The potential for practical applications of polyfluorobenzoic acid derivatives, primarily as biologically active compounds, is presented.The bibliography includes 300 references.

García-Rojas E., Leo P., Tapiador J., Martos C., Orcajo G.

The design of metal–organic frameworks (MOFs) allows the definition of properties for their final application in small-scale heterogeneous catalysis. Incorporating various catalytic centers within a single structure can produce a synergistic effect, which is particularly intriguing for cross-coupling reactions. The URJC-1 material exhibits catalytic duality: the metal centers act as Lewis acid centers, while the nitrogen atoms of the organic ligand must behave as basic centers. The impact of reaction temperature, catalyst concentration, and basic agent concentration was evaluated. Several copper-based catalysts, including homogeneous and heterogeneous MOF catalysts with and without the presence of nitrogen atoms in the organic ligand, were assessed for their catalytic effect under optimal conditions. Among the catalysts tested, URJC-1 exhibited the highest catalytic activity, achieving complete conversion of 4-nitrobenzaldehyde with only 3% mol copper concentration in one hour. Furthermore, URJC-1 maintained its crystalline structure even after five reaction cycles, demonstrating remarkable stability in the reaction medium. The study also examined the impact of various substituents of the substrate alcohol on the reaction using URJC-1. The results showed that the reaction had high activity when activating substituents were present and for most cyclic alcohols rather than linear ones.

Body N., Bevernaegie R., Lefebvre C., Jabin I., Hermans S., Riant O., Troian-Gautier L.

AbstractEarth‐abundant photosensitizers are highly sought after for light‐mediated applications, such as photoredox catalysis, depollution and energy conversion schemes. Homoleptic and heteroleptic copper(I) complexes are promising candidates in this field, as copper is abundant and the corresponding complexes are easily obtained in smooth conditions. However, some heteroleptic copper(I) complexes suffer from low (photo)stability that leads to the gradual formation of the corresponding homoleptic complex. Such degradation pathways are detrimental, especially when recyclability is desired. This study reports a novel approach for the heterogenization of homoleptic and heteroleptic Cu complexes on silica nanoparticles. In both cases, the photophysical properties upon surface immobilization were only slightly affected. Excited‐state quenching with aryl diazonium derivatives occurred efficiently (108–1010 M−1 s−1) with heterogeneous and homogeneous photosensitizers. Moderate but almost identical yields were obtained for the α‐arylation of enol acetate using the homoleptic complex in homogeneous or heterogeneous conditions. Importantly, the silica‐supported photocatalysts were recycled with moderate loss in photoactivity over multiple experiments. Transient absorption spectroscopy confirmed that excited‐state electron transfer occurred from the homogeneous and heterogeneous homoleptic copper(I) complexes to aryl diazonium derivatives, generating the corresponding copper(II) center that persisted for several hundreds of microseconds, compatible with photoredox catalysis applications.

Hosseini R., Ranjbar‐Karimi R., Mohammadiannejad K.

The in-situ generated complex of 3,3’-((naphthalen-2-ylmethylene)bis(4-methoxy-3,1-phenylene))dipyridine L5 with CuI showed excellent activity in Suzuki-Miyaura coupling reactions. The sequential Fridel-Crafts arylation of the derived aldehydes under [P4-VPH][HSO4] catalysis was also used to synthesize a novel series of tetrakis(aryl/heteroaryl) adducts bearing polyconjugated linkages.

Liang L., Wang Y., Li C., Wang H., Yang Q., Li C., Qu G., Guo H., Niu H.

Dehydrogenative coupling of arenes with fluoroaryl nucleophiles enables the efficient synthesis of fluoroaromatic compounds from readily available starting materials.

Hosseinzadeh R., Aghili N., Mavvaji M.

Functionalized nanocellulose was prepared and employed for immobilization of phenanthroline-copper(I) complex to afford cellulose nanofibril grafted heterogeneous copper catalyst [CNF-phen-Cu(I)]. This nanocatalyst was well characterized using FT-IR, NMR, XRD, CHNS, AAS, TGA, EDX and SEM. The activities of the synthesized catalyst were examined in the synthesis of diaryl ethers via C-O cross-coupling of phenols and aryl iodides, as well as, the preparation of N-aryl amides and N-aryl heterocycles through C-N cross-coupling of amides and N-H heterocycle compounds with aryl halides. In this trend, various substrates containing electron-donating and electron-withdrawing groups were exploited to evaluate the generality of this catalytic protocol. Accordingly, the catalyst demonstrated remarkable catalytic efficiency for both C-N and C-O cross-coupling reactions, thereby resulting in good to excellent yields of the desired products. Furthermore, the recoverability experiments of the catalyst showed that it can be readily retrieved by simple filtration and successfully reused several times with negligible loss of its catalytic activity.

Li S., Li W., Yang X., Sun R., Tang J., Zheng X., Yuan M., Li R., Chen H., Fu H.

An efficient protocol of C2-selective direct C–H polyfluoroarylation of six-membered N-heterocyclic compounds with polyfluorobenzoic acid via corresponding N-methyl quaternary ammonium salts.

Habeche F., Hachemaoui M., Mokhtar A., Chikh K., Benali F., Mekki A., Zaoui F., Cherifi Z., Boukoussa B.

Heterogeneous catalysts were used in several production processes for the synthesis of different products such as chemicals, drugs, energy resources, fuels and other specific products. In recent years, mesoporous silica, in particular MCM-41 was widely used in several fields, including catalysis and catalytic support, due to its remarkable textural properties. This material cannot be used directly in catalysis due to its inner surface containing only silanol groups. Therefore, several attempts were proposed in order to obtain an effective catalyst. The immobilization of metal complexes on the surface of mesoporous silica is one of the most popular methods. The metal complexes immobilized on the mesoporous silica MCM-41 exhibit significant catalytic activities due to the increased dispersion of the active sites and the faster diffusion of large organic molecules. The strong interactions between the metal and the ligand generate significant stability for this kind of catalyst, which allows them to be reused in several cycles without losing their efficiency. This review mainly discusses the immobilization strategies of different metal complexes supported on the mesoporous silica MCM-41. A recent study was presented and well detailed based on the different preparation methods, catalytic applications and the stability of metal complexes supported on mesoporous silica MCM-41.

Pentsak E.O., Ananikov V.P.

Solvent‐free reactions belong to a very attractive area of organic chemistry. The solvent‐free Suzuki–Miyaura coupling is of special importance due to the problem of catalyst leaching in the presence of a solvent. This study investigates the course of reaction of solid aryl halides with arylboronic acids in the absence of a solvent and without any liquid additives. For the first time, a number of important conditions for performing a solid‐state Suzuki–Miyaura reaction were analyzed in details. The results indicate a prominent role of water, which is formed as a by‐product in the side reaction of arylboronic acid trimerization. Electron microscopy study revealed surprising changes occurring within the reaction mixture during the reaction and indicated the formation of spherical nano‐sized particles containing the reaction product. Catalyst recycling was easily performed in the developed system and the product was isolated by sublimation, thus providing a possibility to completely avoid the use of solvents at all stages.

Mao S., Shi X., Soulé J., Doucet H.

The potential of the heterogeneous catalyst 10 % Pd/C in the direct arylation of (poly)fluorobenzene derivatives with aryl bromides has been investigated. In general, high yields of biaryl derivatives were obtained by using tri-, tetra-, and pentafluorobenzenes, whereas mono- and difluorobenzenes exhibited poor reactivity. The regioselectivities of the arylation reactions were similar to those observed with homogeneous palladium catalysts. Both electron-withdrawing and -donating substituents, such as nitrile, nitro, acetyl, ester, trifluoromethyl, tert-butyl, methoxy, or methyl, on the aryl bromide were tolerated. Unexpectedly, tetrafluoro-substituted [1,1'-biphenyl]-4-ols were obtained from pentafluorobenzene at 150 °C due to a formal regioselective hydroxylation, whereas at lower temperatures the expected pentafluorobiphenyls were obtained. However, no C-F bond cleavage was observed with the other polyfluorobenzene derivatives. These arylation reactions were carried out with only 1 mol % Pd/C as the catalyst and KOAc as an inexpensive base. Therefore, this protocol represents a very attractive access to (poly)fluoro-substituted biphenyls in terms of cost, simplicity, and sustainable chemistry because the Pd/C catalyst can be easily removed at the end of the reaction, there is no contamination with phosphine ligand residues, and the major side-product of the reaction is KOAc⋅HBr.

Xia J., Huang X., Cai M.

The heterogeneous cascade addition-oxidative cyclization of nitriles with 2-aminopyridines or amidines was achieved in 1,2-dichlorobenzene or DMSO at 120–130 °C by using a 1,10-phenanthroline-functionalized MCM-41-supported copper(I) complex [Phen-MCM-41-CuBr] as the catalyst and air as the oxidant. The approach was used to generate a wide variety of 1,2,4-triazole derivatives in mostly high yields. This heterogeneous copper(I) catalyst could be easily prepared in a two-step procedure from commercially or readily available and inexpensive reagents and it exhibited higher catalytic activity than the CuBr/1,10-Phen system. Phen-MCM-41-CuBr was also easy to recover and was recyclable up to eight times with almost consistent activity.

Hosseini S.H., Zohreh N., Alipour S., Busuioc C., Negrea R.

Gold nanoparticles were decorated on/into the SBA-15 channels covalently functionalized by new class of symmetrical tridentate NNN -pincer ligand. This provides a unique support for stabilization of Au NPs preventing agglomeration due to the strong ligation of pincer ligand. The catalyst proved to be highly active for the reduction of nitroarenes. The kinetics study showed that the rate constant for the current protocol are comparable or larger than the reported ones in literature. The catalyst also showed high recoverability and reusability up to ten times without significant loss of activity and leaching or aggregation of Au NPs (overall TOF = 8798).

Shi X., Mao S., Soulé J., Doucet H.

The higher reactivity of the C4-H bond as compared to the C5-H bond of 1,2,3-trifluorobenzene in palladium-catalyzed direct arylation allows the selective synthesis of 4-aryl-1,2,3-trifluorobenzenes in moderate to high yields. In most cases, phosphine-free Pd(OAc)2 catalyst and inexpensive KOAc base were employed. Then, from these 4-aryl-1,2,3-trifluorobenzenes, the palladium-catalyzed C-H bond functionalization of the C6-position allows the synthesis of the corresponding 4,6-diarylated 1,2,3-trifluorobenzenes. We also applied these reaction conditions to the regioselective direct C3-arylation of 1,2,4-trifluorobenzene.