- Immobilized palladium nanoparticles within polymers as active catalysts for Suzuki-Miyaura reaction
-
A highly active and reusable catalyst Pd@PNP was developed for Suzuki-Miyaura reaction of aryl chlorides and bromides with aryl boronic acids, and the corresponding biphenyl compounds were obtained in good to excellent yields. Triphenylphosphine and palladium nanoparticles were immobilized in situ in the polymer formed from Pd catalyzed coupling of tris(4-bromophenyl)amine and benzene-1,4-diboronic acid. The immobilized triphenylphosphine enhanced the activity and the stability of the catalyst Pd@PNP, and the catalyst Pd@PNP can be reused at least 5 times with good activity. Functional groups, such as methoxyl, nitrile, tert-butyl, nitro, acyl and formyl groups, were well tolerated under the reaction conditions, and the corresponding products were obtained in high yields.
- Chen, Ting,Mao, Fei,Qi, Zhengliang,Li, Yan,Chen, Rizhi,Wang, Yong,Huang, Jun
-
-
Read Online
- Novel polymer incarcerated palladium with phosphinated polymers: Active catalyst for Suzuki-Miyaura coupling without external phosphines
-
(Chemical Equation Presented) Immobilization of a palladium catalyst with use of new phosphinated polymers was carried out utilizing the polymer incarcerated (PI) method. This phosphinated PI Pd catalyst showed excellent activity in Suzuki-Miyaura couplin
- Nishio, Ryo,Sugiura, Masaharu,Kobayashi, Shu
-
-
Read Online
- One-pot preparation of magnetic N-heterocyclic carbene-functionalized silica nanoparticles for the Suzuki-Miyaura coupling of aryl chlorides: Improved activity and facile catalyst recovery
-
Based on a reverse micelle strategy, we successfully synthesized new magnetic silica nanoparticles functionalized with a bulky N-heterocyclic carbene (N,N′-bis(2,6-diisopropylphenyl)imidazol-2-ylidene, denoted as IPr) precursor through the co-condensation of IPr-bridged organosilane and tetraalkoxysilane in a one-pot reaction. TEM and SEM investigations revealed that the particle sizes of the synthesized materials were uniformly distributed in the range 15-30 nm, and could be tuned by varying the amount of siliceous precursors. FT-IR and XPS characterizations showed that the IPr ligand was successfully incorporated onto magnetic silica nanoparticles. Such materials show good coordination capability toward Pd(acac)2 (acac = acetylacetonate), leading to a higher loading in comparison with magnetic silica nanoparticles (without functionalization). This Pd-loaded material is active toward the Suzuki-Miyaura couplings of challenging aryl chlorides under relatively mild conditions (at 80°C). An 81% yield for biphenyl was achieved in the presence of 0.32 mol% of Pd within 8 h, using iso-propyl alcohol as a solvent and KOtBu as a base. The activity of the functionalized nanoparticles is much higher than that of mesoporous silica-based catalysts, as well as a commercial Pd/C catalyst. This catalyst can be easily isolated by using a magnetic field and directly used in the next reaction cycle without significant loss of its activity.
- Yang, Hengquan,Wang, Yunwei,Qin, Yong,Chong, Yanzhu,Yang, Qiaozhen,Li, Guang,Zhang, Li,Li, Wei
-
-
Read Online
- Highly active PdCu/graphene catalyst for an efficient Suzuki cross-coupling reaction
-
A graphene supported Pd-Cu bimetallic catalyst (Pd-Cu/G) has been successfully fabricated by a simple one-pot solvothermal reaction. X-ray diffraction (XRD) analysis as well as morphology characterization demonstrated that Pd-Cu nanoparticles (NPs) are uniformly distributed on the graphene nanosheets. When adopted as the catalyst for the Suzuki cross-coupling reaction, this hybrid exhibited excellent catalytic activity (99.9% conversion) as well as desirable selectivity (99.9%). After recycling five times, the high yield and selectivity were well maintained, illustrating the high durability of this catalyst. This journal is
- M., Xiaojing,Gao, Lingfeng,Weng, Zhentao,Yang, Hua,Sun, Xu
-
-
Read Online
- Polyfluorinated phosphine ligands in the room temperature Suzuki cross-coupling reactions
-
Polyfluorinated phosphine ligands can be obtained by regioselective nucleophilic aromatic substitution on tetrafluoronaphthalene derivatives. The ligand efficiency has been demonstrated in the room temperature Suzuki coupling reactions of aryl bromides an
- Yekta, Shahla,Cheung, Lawrence,Yudin, Andrei K.
-
-
Read Online
- Studies on the functionalization of MWNTs and their application as a recyclable catalyst for CC bond coupling reactions
-
Functionalization of multi-walled carbon nanotubes (MWNTs) was studied using various anchoring methods. Among them, nitrene chemistry was employed as the method of choice to preserve desirable physical properties of MWNTs. Using this method, synthesis of carboxyl-functionalized carbon nanotubes (CNTs) was achieved, and then transition metals were incorporated on the linker-MWNT via reductive methods using hydrazine monohydrate. Among various reducing reagents, the use of hydrazine hydrate allowed us to load palladium uniformly. After immobilization of palladium on CNT, its role as a catalyst for CC bond coupling reaction (Suzuki reaction) was examined. The catalysts could be retrieved upon completion of the reaction by filtration and drying; the recycled catalysts could then be used in further reactions up to seven times before any loss in catalytic activity was observed. Further studies revealed that the Pd leached out of the MWNT may be responsible for the reactivity.
- Kim, Eunsuk,Jeong, Han Saem,Kim, B. Moon
-
-
Read Online
- The catalytic ability of various transition metals in the direct functionalization of aromatic C-H bonds
-
From noble to normal: Many transition-metal complexes have shown a remarkable ability to catalyze the cross-coupling of aryl halides with arenes (see scheme). The formation of biaryls has thus been achieved using inexpensive, readily available, and sometimes nontoxic transition-metal complexes. Not only "noble" transition metals, but also many of the "normal" transition metals are able to promote the direct transformation of C-H bonds.
- Li, Hu,Sun, Chang-Liang,Yu, Miao,Yu, Da-Gang,Li, Bi-Jie,Shi, Zhang-Jie
-
-
Read Online
- Solid-phase synthesis of biphenyls and terphenyls by the traceless multifunctional cleavage of polymer-bound arenesulfonates
-
Nickel-catalyzed reactions between polymer-bound arene-sulfonates and aryl Grignard reagents produce unfunctionalized biphenyls and terphenyls in good yields through reductive cleavage/cross-coupling of the C-S bond. This novel traceless multifunctional cleavage strategy appears to be a powerful tool for the preparation of large oligophenyl libraries, because it allows the introduction of diversity concomitantly with the release of the target compounds. Wiley-VCH Verlag GmbH & Co. KGaA, 2005.
- Cho, Chul-Hee,Park, Heon,Park, Min-Ah,Ryoo, Tae-Yong,Lee, Yoon-Sik,Park, Kwangyong
-
-
Read Online
- A self-supported palladium-bipyridyl catalyst for the Suzuki-Miyaura coupling in water
-
A self-supported palladium catalyst (PdCI2BPy-Cu) was prepared via construction of a metal-organic framework (MOF) of a bipyridyl-palladium complex bearing carboxylic groups and a copper(II) linker. PdCI2BPy-Cu efficiently catalyzed the Suzuki-Miyaura coupling of phenyl halides with arylboronic acids in water under atmospheric conditions to afford the corresponding biaryl products in high yield. The catalyst was reused four times without loss of catalytic activity.
- Osako, Takao,Uozumi, Yasuhiro
-
-
Read Online
- Intermetallic ZrPd3?embedded nanoporous ZrC as an efficient and stable catalyst of the Suzuki cross-coupling reaction
-
The Suzuki cross-coupling reaction, which is generally catalyzed by Pd-based materials, is a practical approach to create C?C bonds. Although heterogeneous catalysts, including metal-loaded and intermetallic catalysts, afford simple reaction conditions and catalyst reusability, it is challenging to achieve high catalytic activity, durability, and Pd-atom economy together in a single catalyst. Herein, we report the successful preparation of Pd?ZrC, a Pd-based catalyst with the described desirable features. In it, a-few-nanometer-sized nanoparticles of intermetallic ZrPd3 are uniformly dispersed on the surface of nanoporous ZrC with a surface area of 340?450 m2 g?1. As a result of the presence of electron-rich Pd sites and the material’s strong electron-donating ability, Pd?ZrC achieved high catalytic performance in Suzuki cross-coupling reactions at room temperature. Because a low Pd content (1 wt %) is sufficient to produce highly catalytically active Pd?ZrC, this material represents a great improvement in terms of Pd-atom economy over previously reported catalysts. Moreover, no catalytic degradation was noted over up to the presented 15 reaction cycles as the active Pd sites were stabilized in the ZrPd3 lattice. These results indicate that Pd?ZrC has the advantages of both metal-loaded and intermetallic catalysts, providing an approach to enhance the degree of freedom for designing heterogeneous catalysts.
- Lu, Yangfan,Ye, Tian-Nan,Park, Sang-Won,Li, Jiang,Sasase, Masato,Abe, Hitoshi,Niwa, Yasuhiro,Kitano, Masaaki,Hosono, Hideo
-
-
Read Online
- Pd–Ni bimetallic nanoparticles supported on ZrO2 as an efficient catalyst for Suzuki–Miyaura reactions
-
Pd–Ni bimetallic nanoparticles (BMNPs) supported on ZrO2 were prepared by an impregnation–reduction method. The BMNPs showed excellent catalytic performance in Suzuki carbon–carbon cross-coupling reactions and almost quantitative conversion of the substrates was obtained under mild conditions in the absence of ligand. The excellent catalytic performance of the bimetallic catalyst could be a result of the synergistic effect between the two metal components. The catalyst showed outstanding recyclability during the reaction process; no obvious decrease in catalytic performance was observed after five cycles.
- Zhang, Li-Jie,Yao, Xian,Sun, Ying-xin,Zhang, Jia-wei,Cai, Chun
-
-
Read Online
- Homogeneous ruthenium precatalyst for suzuki-miyaura coupling reaction
-
Ru(cod)(2-methylallyl)2 was found to catalyze the SuzukiMiyaura cross-coupling reaction of aryl bromides and aryl iodides with arylboronic acids. The reaction was catalyzed by 10 mol% Ru(cod)(2-methylallyl)2 at 60°C, and afforded the biaryls in moderate to good yields.
- Kawatsura, Motoi,Kamesaki, Kosuke,Yamamoto, Mitsuaki,Hayase, Shuichi,Itoh, Toshiyuki
-
-
Read Online
- Self-assembled Pd6L4 cage and Pd4L4 square using hydrazide based ligands: Synthesis, characterization and catalytic activity in Suzuki-Miyaura coupling reactions
-
A discrete Pd6L4Td-symmetric molecular cage and a discrete Pd4L4 square assembly were obtained using a coordination-driven self-assembly technique. The assembly, Pd6L4, was prepared via a face-directed method, utilising a 'cis-clipped' palladium(ii) species and a new C3 symmetric tripodal hydrazinic ligand. The Pd4L4 square assembly was prepared via an edge directed method, using the 'cis-clipped'-palladium(ii) species and a new C2 symmetric dipodal hydrazinic ligand. Both assemblies were characterised using multinuclear NMR and ESI-MS spectroscopic techniques and elemental analysis. The size of the assemblies were assigned from HR-TEM measurements, while DOSY NMR analysis established the presence of single component species in solution. Optimised structures obtained using Hartree-Fock calculations are in conformity with the experimental results. Both the assemblies show significant catalytic activity as heterogeneous catalysts for Suzuki-Miyaura coupling reactions under mild, aerobic and phosphine free conditions in aqueous ethanolic medium.
- Pradhan, Subhashis,John, Rohith P.
-
-
Read Online
- AlAr3(THF): Highly efficient reagents for cross-couplings with aryl bromides and chlorides catalyzed by the economic palladium complex of PCy3
-
Novel and highly efficient cross couplings of aryl bromides and chlorides with AlAr3(THF) (Ar = Ph, 2,4,6-Me3C6H 2, 2-naphthyl or 4-Me3SiC6H4) catalyzed by the economic palladium catalyst of PCy3 are reported without the use of a base and under mild reaction conditions at room temperature or temperatures ≤60°C even for couplings of bulky aryl halides and the Al(2,4,6-Me3C6H2)3(THF) reagent. The Royal Society of Chemistry.
- Ku, Shih-Lun,Hui, Xin-Ping,Chen, Chien-An,Kuo, Yi-Ying,Gau, Han-Mou
-
-
Read Online
- Bulky N-acyl-pyridylbenzamidine ligands for palladium catalyzed Suzuki-Miyaura reaction
-
In this letter, a series of bulky N-acyl-pyridylbenzamidine ligands were synthesized and characterized. Under the optimized reaction conditions, these bulky ligands were applied to catalyze Suzuki-Miyaura reactions of various aryl bromides and chlorides. The desired biaryl products were obtained in good to high yields.
- Tan, Cheng,Liu, Feng-Shou,Shen, Dong-Sheng,Cheng, Tao,Zhou, Zong-Zhou
-
-
Read Online
- Water-Soluble Palladium(II) Sulfonated Thiosemicarbazone Complexes: Facile Synthesis and Preliminary Catalytic Studies in the Suzuki-Miyaura Cross-Coupling Reaction in Water
-
A series of mono- and binuclear sulfonated thiosemicarbazone PdII complexes have been synthesised and characterised using nuclear magnetic resonance spectroscopy, infrared spectroscopy, electrospray ionisation mass spectrometry and elemental analysis. The complexes display excellent water-solubility at room temperature and in addition, 1H and 31P{1H} NMR spectroscopic experiments reveal that the mononuclear complex 4 is very stable in water at 70 °C. Consequently, preliminary catalytic experiments show the water-soluble complexes to be efficient catalyst precursors in the Suzuki-Miyaura cross-coupling reaction in water. No evidence of homo-coupling was observed and the water-soluble complexes demonstrated versatility in coupling substrates containing various functional groups. Mono- and binuclear thiosemicarbazone complexes were synthesized and characterized. The mononuclear complexes are very stable in water and all the catalysts are active for the Suzuki-Miyaura cross-coupling reaction of various substrates. The mononuclear catalysts were more active than their binuclear analogues. Catalyst 4 could be recycled efficiently twice.
- Matsinha, Leah C.,Mao, Jincheng,Mapolie, Selwyn F.,Smith, Gregory S.
-
-
Read Online
- Polymer-supported palladium (II) containing N2O2: An efficient and robust heterogeneous catalyst for C–C coupling reactions
-
A new polymer was prepared from 1,3,5-triformylphloroglucinol (noted as TDTB) and o-phenylenediamine through Schiff base condensation reaction, and palladium (II) was immobilized on the polymer (noted as TbPo-Pd(II)). This process was easy to work-up and cost-effective. The structure and composition of TbPo-Pd(II) were fully characterized by FTIR, TGA, XPS, AAS, SEM, and TEM analyses. Meanwhile, this catalyst showed desired thermal stability and excellent performance in water/methanol system for Suzuki and Sonogashira coupling reactions. In addition, this heterogeneous catalyst can be readily recovered by simple filtration with no appreciable Pd leaching in the reaction. This work provides a powerful protocol for rapid access to asymmetrical biphenyls and aryl alkynes.
- Bi, Jiajun,Chen, Jian,Dong, Yahao,Guo, Wen,Zhu, Dajian,Li, Tao
-
-
Read Online
- Highly active palladium catalysts for Suzuki coupling reactions
-
Mixtures of palladium acetate and o-(di-tert-butylphosphino)biphenyl (4) catalyze the room-temperature Suzuki coupling of aryl bromides and aryl chlorides with 0.5-1.0 mol % Pd. Use of o-(dicyclohexylphosphino)biphenyl (2) allows Suzuki couplings to be carried out at low catalyst loadings (0.000001-0.02 mol % Pd). The process tolerates a broad range of functional groups and substrate combinations including the use of sterically hindered substrates. This is the most active catalyst system in terms of reaction temperature, turnover number, and steric tolerance which has been reported to date.
- Wolfe, John P.,Singer, Robert A.,Yang, Bryant H.,Buchwald, Stephen L.
-
-
Read Online
- Magnetically recyclable hollow nanocomposite catalysts for heterogeneous reduction of nitroarenes and Suzuki reactions
-
Highly active magnetically recyclable hollow nanocomposite catalysts with a permeable carbon surface have been prepared by a simple, economical and scalable process. The designed nanocomposite exhibited excellent catalytic activities in the selective reduction of nitroarenes and Suzuki cross-coupling reactions. The catalysts could be easily separated by a magnet, and recycled consecutively.
- Shokouhimehr, Mohammadreza,Lee, Ji Eun,Han, Sang Ihn,Hyeon, Taeghwan
-
-
Read Online
- NHC-Pd complex heterogenized on graphene oxide for cross-coupling reactions and supercapacitor applications
-
N-heterocyclic carbene (NHC)-palladium(II) complex (GO@NHC-Pd) was synthesized on graphene oxide (GO) support via a simple and cost-effective multistep approach. The spectroscopic, microscopic, thermal, and surface analyses of GO@NHC-Pd confirmed the successful formation of the catalyst. The investigation of catalytic activity showed that GO@NHC-Pd was very effective in Suzuki–Miyaura as well as Hiyama cross-coupling. Being heterogeneous in nature, GO@NHC-Pd was recovered after each reaction cycle easily and reused for up to nine and six cycles in Suzuki–Miyaura and Hiyama cross-coupling, respectively, without significant loss of activity. Further exploration of the supercapacitor performance of GO@NHC-Pd catalyst assembled in a two-electrode cell configuration shown a maximum attained capacitance of 105.26 F/g at a current density of 0.1 A/g with good cycling stability of 96.89% over 2,500 cycles.
- Kandathil, Vishal,Siddiqa, Aisha,Patra, Abhinandan,Kulkarni, Bhakti,Kempasiddaiah, Manjunatha,Sasidhar,Patil, Shivaputra A.,Rout, Chandra Sekhar,Patil, Siddappa A.
-
-
Read Online
- Crystalline mesoporous γ-Al2O3 supported palladium: Novel and efficient catalyst for Suzuki-Miyaura reaction under controlled microwave heating
-
Crystalline mesoporous γ-Al2O3 has been successfully synthesized under high temperature hydrothermal conditions and used as anexcellent support for Pd(OAc)2. The resulting γ-Al 2O3-Pd showed excellent catalytic activity for Suzuki-Miyaura cross-coupling reaction. As low as 0.2 mol% loading of Pd was needed to obtain cross-coupling products in good to excellent yields in aqueous DMF under microwave irradiation. Moreover, the novel catalyst can be easily recovered by filtration and reused without any diminishing observable activity after five runs.
- Feng, Gaofeng,Liu, Fujian,Lin, Chen,Li, Weiting,Wang, Shengnan,Qi, Chenze
-
-
Read Online
- Magnetic Fe-Ni Alloy Catalyzed Suzuki Cross-Coupling Reactions of Aryl Halides with Phenylboronic Acid
-
Alloy there matey! The inexpensive and readily prepared magnetic Fe-Ni alloy is employed in the Suzuki reactions of aryl halides with phenylboronic acid. The products are obtained in moderate to excellent yields in the absence of a reducing agent. The magnetic nature of the catalyst is beneficial for the separation of the products, but the recyclability of the catalyst is poor, probably as a result of oxidation and leaching.
- Zhang, Rongzhao,Miao, Chengxia,Wang, Shoufeng,Xia, Chungu,Sun, Wei
-
-
Read Online
- Strategy used to synthesize high activity and low Pd catalyst for Suzuki coupling reaction: An experimental and theoretical investigation
-
Unveiling the reaction mechanism is significant for developing high-performance catalysts. In this paper, a series of precisely controlled PdxM147-x (M = Cu, Pt, Au, Rh, Ru) dendrimer encapsulated nanoparticles (DENs) has been successfully synthesized. The mechanisms of PdxM147-x as catalysts for Suzuki cross-coupling reactions were investigated by combining experimental and theoretical methods. The experimental results indicate that Pd74Cu73 DEN shows similar activity to Pd147 DEN and excellent substrate adaptability under mild reaction conditions. Moreover, the Cu component can play an important role in tuning the catalytic activity of PdxCu147-x DEN. Density functional theory (DFT) calculations illustrate that the similar activities of the Pd147 and Pd74Cu73 DENs originate from the comparable energy barriers of the rate-determining steps. The partial density of states (PDOS) and electron density differences demonstrate that Cu decreases the intensities of the valence orbitals of the top and edge Pd atoms and weakens orbital interactions between the intermediates and Pd74Cu73 DEN, leading to low desorption energies of the products. This work can provide a promising strategy to reduce the cost of Pd catalysts in Suzuki cross-coupling reactions.
- Chen, Zhongzhu,Gan, Ya,Hu, Jianping,Liang, Li,Liu, Wei,Luo, Yafei,Shi, Hubing,Tang, Dianyong,Wan, Hua,Xu, Zhigang,Yan, Xiao
-
-
Read Online
- Polyureas derived from CO2 and diamines: highly efficient catalysts for C-H arylation of benzene
-
Polyureas derived from CO2 and diamines were effective for C-H arylation of benzene in the presence of t-BuOK, producing biaryl products with various substituents in high yields up to 97%. Dual-activation of K+ and t-BuO-, and π,π-stacking interaction between the substrate and the polymer backbone may account for the superior activity.
- Liu, Zhenghui,Yang, Zhenzhen,Hao, Leiduan,Liu, Xinwei,Zhang, Hongye,Yu, Bo,Liu, Zhimin
-
-
Read Online
- Synthesis, characterization and catalytic performance of palladium supported on pyridine-based covalent organic polymer for Suzuki-Miyaura reaction
-
A bipyridine-based covalent organic polymer (COP) was successfully synthesized by condensation of trimesoyl chloride (TMC) and 2,2′-bipyridine-5,5′-diamine (Bpy) under ambient conditions. This material was modified by coordination of PdCl2 to COP framework, affording a hybrid material, Pd@TMC-Bpy COP, which was applied as a highly efficient heterogeneous catalyst for Suzuki-Miyaura reaction under ligand-free conditions in ethyl lactate. The catalyst could be reused for five times without obvious loss of its activity.
- Han, Yi,Di, Jia-Qi,Zhao, Ai-Dong,Zhang, Zhan-Hui
-
-
Read Online
- [PdCl2{8-(di-tert-butylphosphinooxy)quinoline)}]: a highly efficient catalyst for Suzuki-Miyaura reaction
-
The complex [PdCl2(P-N)] containing the basic and sterically demanding 8-(di-tert-butylphosphinooxy)quinoline ligand (P-N) is a highly efficient catalyst for the coupling of phenylboronic acid with aryl bromides or aryl chlorides. The influence of solvent and base has been investigated, the highest rates being observed at 110 °C in toluene with K2CO3 as the base. With aryl bromides the reaction rates are almost independent on the electronic properties of the para aryl substituents, on the contrary, reduced reaction rates are observed when bulky substituents are present on the substrate. Nevertheless the coupling of 2-bromo-1,3,5-trimethylbenzene with phenylboronic acid can be carried out to completion in 2 h using a catalyst loading of 0.02 mol %. Under optimized reaction conditions, turnover frequencies as high as 1900 h-1 can be obtained in the coupling of 4-chloroacetophenone with phenylboronic acid; lower reaction rates are obtained with substrates bearing EDG substituents on the aryl group.
- Scrivanti,Bertoldini,Matteoli,Antonaroli,Crociani
-
-
Read Online
- Confirmation of Suzuki-Miyaura Cross-Coupling Reaction Mechanism through Synthetic Architecture of Nanocatalysts
-
Despite widespread use of heterogeneous Pd catalysts in Suzuki-Miyaura coupling reactions, detailed roles of Pd, especially the nature of its active species, are still a topic of controversial debate. While some studies showed an active surface of Pd nanoparticles or nanoclusters acting heterogeneously, others claimed soluble Pd species leached from the metallic Pd to be active species which are homogeneous in nature. Besides, within the homogeneous mechanism, how the Pd leaches and promotes the cross-coupling reaction is then another question that needs to be addressed. It could be envisioned that if the soluble Pd species and solid-phase Pd are physically separated, the mechanism of Suzuki-Miyaura coupling could then be confirmed through examining the catalytic activity in different reaction regions. Herein we use microporous St?ber silica as a membrane to separate the soluble Pd species from solid Pd and conduct size-selective reactions which allow the passage of leaching Pd species, but not of reactants or products larger than the membrane aperture. With this strategy, we have been able to differentiate the surface reaction from the solution cross-coupling. We find that the leached Pd species are the only genuine catalytic intermediate in the cross-coupling reactions. We also confirm that oxidative addition of aryl halides to the solid Pd leads to leaching of the soluble Pd species which is necessary to promote Suzuki-Miyaura reactions.
- Sun, Bo,Ning, Lulu,Zeng, Hua Chun
-
-
Read Online
- Palladium(II)-exchanged hydroxyapatite-catalyzed Suzuki-Miyaura-type cross-coupling reactions with potassium aryltrifluoroborates
-
Palladium(II)-exchanged hydroxyapatite (PdHAP; Pd/Ca ratio = ca. 1/200) was prepared by ion-exchanging with Ca2+ from calcined hydroxyapatite (2.0 mmol) and Pd(NO3)2 (0.10 mmol) in water (150 mL) at 70 °C for 24 h. The PdHAP (1 mol% Pd to aryl bromides) functioned as a catalyst for the Suzuki-Miyaura-type cross-coupling reaction of aryl bromides and potassium aryltrifluoroborates with triphenylphosphine (1 mol%) and excess potassium carbonate at 50 °C in methanol under air. This cross-coupling reaction was found to proceed in water, while the rate was slow compared with that in methanol. The heterogeneous PdHAP catalyst was used ten times repeatedly at 50 °C in methanol under air, though its catalytic activity gradually declined. XRD and XRF analyses and TEM images revealed that most of palladium species would still be supported as isolated ions on the repeatedly used PdHAP, in spite of the changes of the structure and composition of PdHAP surface at the late stages in the repetitive uses and the partial leaching of Pd species at the initial stages in the repetitive uses. The gradual decline of the catalytic activity might be dependent on either the changes of PdHAP surface at the late stages or the partial leaching of Pd species at the initial stages. Still, heterogeneous PdHAP served as a reusable catalyst for Suzuki-Miyaura-type cross-coupling reaction with potassium aryltrifluoroborates.
- Masuyama, Yoshiro,Sugioka, Yutaka,Chonan, Shiori,Suzuki, Noriyuki,Fujita, Masahiro,Hara, Kenji,Fukuoka, Atsushi
-
-
Read Online
- Pd-catalyzed desulfitative Hiyama coupling with sulfonyl chlorides
-
Palladium-catalyzed desulfitative Hiyama cross-coupling reactions of various arylsulfonyl chlorides with aryltriethoxysilane have been achieved in good yields. The reported cross-coupling reactions are tolerant to the common functional groups regardless o
- Zhang, Wei,Liu, Fang,Li, Ke,Zhao, Baoli
-
-
Read Online
- A robust and efficient Pd3 cluster catalyst for the suzuki reaction and its odd mechanism
-
The palladium-catalyzed Suzuki-Miyaura coupling reaction is one of the most versatile and powerful tools for constructing synthetically useful unsymmetrical aryl-aryl bonds. In designing a Pd cluster as a candidate for efficient catalysis and mechanistic investigations, it was envisaged to study a case intermediate between, although very different from, the "classic" Pd(0)Ln and Pd nanoparticle families of catalysts. In this work, the cluster [Pd3Cl(PPh2)2(PPh3)3]+[SbF6]- (abbreviated Pd3Cl) was synthesized and fully characterized as a remarkably robust framework that is stable up to 170 °C and fully air-stable. Pd3Cl was found to catalyze the Suzuki-Miyaura C-C crosscoupling of a variety of aryl bromides and arylboronic acids under ambient aerobic conditions. The reaction proceeds while keeping the integrity of the cluster framework all along the catalytic cycle via the intermediate Pd3Ar, as evidenced by mass spectrometry and quick X-ray absorption fine structure. In the absence of the substrate under the reaction conditions, the Pd3OH species was detected by mass spectrometry, which strongly favors the "oxo-Pd" pathway for the transmetalation step involving substitution of the Cl ligand by OH followed by binding of the OH ligand with the arylboronic acid. The kinetics of the Suzuki- Miyaura reaction shows a lack of an induction period, consistent with the lack of cluster dissociation. This study may provide new perspectives for the catalytic mechanisms of C-C cross-coupling reactions catalyzed by metal clusters.
- Fu, Fangyu,Xiang, Ji,Cheng, Hao,Cheng, Longjiu,Chong, Hanbao,Wang, Shuxin,Li, Peng,Wei, Shiqiang,Zhu, Manzhou,Li, Yadong
-
-
Read Online
- 3D graphene/nylon rope as a skeleton for noble metal nanocatalysts for highly efficient heterogeneous continuous-flow reactions
-
Continuous-flow catalytic systems represent a highly efficient approach towards scalable synthesis with features of time and energy saving, easy operation, and improved safety. Herein, we rationally design a novel 3D noble metal/graphene/nylon rope to act as a highly efficient catalyst for continuous-flow organic reactions. We show that different noble metal (Pd, Pt, Au and Ag) nanocatalysts and graphene can be readily assembled with the chemically inert nylon rope by a one-step hydrothermal method. Graphene, acting as the interconnector for noble metal nanoparticles and the nylon rope, increases the flexibility and mechanical strength of rope-like catalysts and improves the catalytic activity and stability of the noble metal species. The large voids within the noble metal/graphene/nylon rope catalysts, under optimized reaction conditions, ensure the sufficient chemical transfer for the continuous-flow system. The high catalytic activity and stability of rope catalysts are demonstrated by the Suzuki-Miyaura cross-coupling reaction (SMC) and 4-nitrophenol reduction reaction. Pd/graphene/nylon rope catalysts show a high turnover number of 965 mol h-1 molPd-1, a large productivity of 1385 mg h-1 mgPd-1 at a flow rate of 70 mL h-1, and a remarkable stability for continuous-flow SMC reactions. Such a novel minifluidic system integrated with 3D noble metal/graphene/nylon rope catalysts can be extended to many important chemical reactions. This journal is
- Zhang, Sai,Shen, Xuetao,Zheng, Zhiping,Ma, Yuanyuan,Qu, Yongquan
-
-
Read Online
- An active and recyclable polystyrene-supported N-heterocyclic carbene-palladium catalyst for the Suzuki reaction of arylbromides with arylboronic acids under mild conditions
-
A novel polymer-supported imidazolium salt has been prepared from a bisimidazolium salt and cross-linked chloromethyl polystyrene. The polymer-supported N-heterocyclic carbene-palladium complex, generated from the supported bisimidazolium salt and Pd(OAc)2, efficiently catalyzed the Suzuki coupling reaction of aryl bromides and arylboronic acids under air in aqueous DMF solution at room temperature, giving biaryls in good to excellent yields. The catalyst could be reused several times still retaining high activity. Georg Thieme Verlag Stuttgart.
- Kang, Tairan,Feng, Qiang,Luo, Meiming
-
-
Read Online
- N-Doped porous carbon nanotubes: Synthesis and application in catalysis
-
Uniform N-doped carbon nanotubes were obtained for the first time via a morphology-preserving thermal transformation of organic polymer nanotubes without any additional templates. These carbon nanotubes acted as a superior metal-free carbon catalyst for C-H arylation of benzene, reductive hydrogen atom transfer and oxidation reactions.
- Yang, Zhenzhen,Liu, Zhenghui,Zhang, Hongye,Yu, Bo,Zhao, Yanfei,Wang, Huan,Ji, Guipeng,Chen, Yu,Liu, Xinwei,Liu, Zhimin
-
-
Read Online
- Nickel-catalyzed C(sp2)-C(sp2) cross coupling reactions of sulfur-functionalities and Grignard reagents
-
In the present study, the nickel-catalyzed carbon carbon bond formation of a range of sulfur containing substrates with Grignard reagents via desulfurization has been explored. After investigation of different reaction parameters with a well-defined nickel complex an excellent and easy-accessible pre-catalyst was found. The obtained system was capable to convert a broad scope of substrates under mild reaction conditions. Graphical Abstract: [Figure not available: see fulltext.]
- Someya, Chika I.,Weidauer, Maik,Enthaler, Stephan
-
-
Read Online
- 'Awaken' aryl sulfonyl fluoride: a new partner in the Suzuki-Miyaura coupling reaction
-
An example of the activation of the -SO2F group, which is traditionally considered a stable group even in the presence of a transition metal, is described using a novel partner in the Suzuki-Miyaura coupling reaction catalyzed by Pd(OAc)2 and Ruphos as ligands. The products showed good to outstanding yields and broad functional group compatibility under optimal conditions. The sequential synthesis of non-symmetric terphenyls and the gram grade process highlight the approach's synthetic utility. DFT calculations have shown that Pd0 prefers to insert between C-S bonds rather than S-F bonds. This journal is
- Ding, Chengrong,Guan, Chenfei,Miao, Huihui,Zhang, Guofu,Zhao, Yiyong
-
p. 3560 - 3564
(2022/03/07)
-
- Organocatalytic synthesis of (Het)biaryl scaffoldsviaphotoinduced intra/intermolecular C(sp2)-H arylation by 2-pyridone derivatives
-
A uniqueN,O-bidentate ligand 6-oxo-1,6-dihydro-pyridone-2-carboxylic acid dimethylamide (L1) catalyzed direct C(sp2)-H (intra/intermolecular) arylation of unactivated arenes has been developed to expedite access to (Het)biaryl scaffolds under UV-irradiation at room temperature. The protocol tolerated diverse functional groups and substitution patterns, affording the target products in moderate to excellent yields. Mechanistic investigations were also carried out to better understand the reaction pathway. Furthermore, the synthetic applicability of this unified approach has been showcasedviathe construction of biologically relevant 4-quinolone, tricyclic lactam and sultam derivatives.
- Das, Tapas Kumar,Kundu, Mrinalkanti,Mondal, Biswajit,Ghosh, Prasanjit,Das, Sajal
-
p. 208 - 218
(2021/12/29)
-
- Amino acid-derived bisphenolate palladium complexes as C-C coupling catalysts
-
A series of amine bisphenol (ABP) pro-ligands featuring amino acid ester pendant arms were prepared. Optimisation of the synthetic method allowed the facile incorporation of naturally occurring, chiral amino acids into the ABP scaffold with minimal racemi
- Fazekas, Eszter,Forbes, Andrew A.,Gallagher, Brendan,Jenkins, David T.,McIntosh, Ruaraidh D.,Rosair, Georgina M.
-
p. 17625 - 17634
(2021/12/20)
-
- Photoelectric properties of aromatic triangular tri-palladium complexes and their catalytic applications in the Suzuki-Miyaura coupling reaction
-
The photoelectric properties and catalytic activities of substituted triphenylphosphine and sulfur/selenium ligand supported aromatic triangular tri-palladium complexes1-4, abbreviated as [Pd3]+, were investigated. The cyclic voltammogram of [Pd3]+in CH3CN-nBu4NPF6showed a single quasi-reversible wave which was consistent with their robust property and provided preliminary proof for their electron transfer processes in catalysis. With excitation at 267 nm, [Pd3]+exhibited strong ratiometric fluorescence at 550 and 780 nm at a temperature gradient from 77 K to 287 K. These peculiar triangular tri-palladium complexes showed excellent catalytic activities and exclusive reactivity with aryl iodides over the other halogenated aromatics in the Suzuki-Miyaura coupling reaction. The electronic and steric hindrance effects of substituents on the aryl iodides and aryl boronic acids including heteroaromatics like pyridine, pyrazine and thiophenes were explored and most substrates achieved up to 99% of yields. (2-[1,1′-Biphenyl]-2-ylbenzothiazole) which was analogous to the selective cyclooxygenase-2 (COX-2) inhibitors was also synthesized with our tri-palladium catalyst and gave good isolated yield (94%). The study of the catalytic process revealed that the mechanism of the reaction may involve the replacement of the sulphur ligand on [Pd3]+by iodine from aryl iodides, which was beneficial for the matching of C-I bond energy.
- Li, Xujun,Li, Jia,Wang, Xiaoshuang,Wu, Lingang,Wang, Yanlan,Maestri, Giovanni,Malacria, Max,Liu, Xiang
-
supporting information
p. 11834 - 11842
(2021/09/06)
-
- Structural and catalytic properties of the [Ni(BIPHEP)X2] complexes, BIPHEP = 2,2-diphenylphosphino-1,1-biphenyl; X = Cl, Br
-
The synthesis and catalytic properties in Kumada C–C coupling of the [Ni(BIPHEP)X2] complexes, X = Cl (1), Br (2), are described. The crystal structures of the BIPHEP ligand and 2 are also presented and compared with previously reported crystal structures of atropisomeric bidentate phosphine ligands (P,P) and related [M(P,P)X2] complexes (M = Ni, Pd, Pt). BIPHEP crystallizes in the C2/c space group, with both enantiomers present in the unit cell. This is consistent with BIPHEP being a “tropos” ligand. Complex 2 crystallizes in the P21/a space group. There are two symmetry-independent molecules in the asymmetric unit, namely 2a and 2b, in which the BIPHEP ligand adopts the S or the R configuration, respectively. Complexes 2a and 2b exhibit a severely tetrahedrally-distorted square planar NiP2Br2 coordination sphere, with a PNiP bite angle of 93.3° and 94.7°, respectively. The observed catalytic behavior of complexes 1 and 2 in the Kumada coupling between p-tert-butyl-halogenobenzene and p-tolylmagnesium chloride is benchmarked against that of [Ni(dppp)Cl2], dppp = 1,3-bis(diphenylphoshpino)propane. However, all three complexes are catalytically inactive in the Suzuki-Miyaura coupling reaction.
- Ioannou, Polydoros-Chrysovalantis,Grigoropoulos, Alexios,Stergiou, Konstantina,Raptopoulou, Catherine P.,Psycharis, Vassilis,Svoboda, Jan,Kyritsis, Panayotis,Vohlídal, Ji?í
-
-
- A Practice of Reticular Chemistry: Construction of a Robust Mesoporous Palladium Metal-Organic Framework via Metal Metathesis
-
Constructing stable palladium(II)-based metal-organic frameworks (MOFs) would unlock more opportunities for MOF chemistry, particularly toward applications in catalysis. However, their availability is limited by synthetic challenges due to the inertness of the Pd-ligand coordination bond, as well as the strong tendency of the Pd(II) source to be reduced under typical solvothermal conditions. Under the guidance of reticular chemistry, herein, we present the first example of an azolate Pd-MOF, BUT-33(Pd), obtained via a deuterated solvent-assisted metal metathesis. BUT-33(Pd) retains the underlying sodalite network and mesoporosity of the template BUT-33(Ni) and shows excellent chemical stability (resistance to an 8 M NaOH aqueous solution). With rich Pd(II) sites in the atomically precise distribution, it also demonstrates good performances as a heterogeneous Pd(II) catalyst in a wide application scope, including Suzuki/Heck coupling reactions and photocatalytic CO2 reduction to CH4. This work highlights a feasible approach to reticularly construct noble metal based MOFs via metal metathesis, in which various merits, including high chemical stability, large pores, and tunable functions, have been integrated for addressing challenging tasks.
- He, Tao,Kong, Xiang-Jing,Li, Jian-Rong,Lv, Xiu-Liang,Nie, Zuo-Ren,Si, Guang-Rui,Wang, Kecheng,Wu, Xue-Qian,Zhao, Chen,Zhou, Jian
-
supporting information
p. 9901 - 9911
(2021/07/21)
-
- Arylketones as Aryl Donors in Palladium-Catalyzed Suzuki-Miyaura Couplings
-
Herein, we report the arylation, alkylation, and alkenylation of aryl ketones via a palladium-catalyzed Suzuki-Miyaura cross-coupling reaction. The use of the pyridine-oxazoline ligand is the key to the cleavage of the unstrained C-C bond. The late-stage arylation of aryl ketones derived from drugs and natural products demonstrated the synthetic utility of this protocol.
- Wang, Zhen-Yu,Ma, Biao,Xu, Hui,Wang, Xing,Zhang, Xu,Dai, Hui-Xiong
-
supporting information
p. 8291 - 8295
(2021/11/13)
-
- Cobalt-Catalyzed Coupling of Aryl Chlorides with Aryl Boron Esters Activated by Alkoxides
-
The cobalt-catalyzed Suzuki biaryl cross-coupling of aryl chloride substrates with aryl boron reagents, activated with more commonly used bases, remained a significant unmet challenge in the race to replace platinum group metal catalysts with Earth-abundant metal alternatives. We now show that this highly desirable process can be realized using alkoxide bases, provided the right counterion is employed, strict stoichiometric control of the base is maintained with respect to the aryl boron reagent, and the correct boron ester is selected. Potassium tert-butoxide works well, but any excess of the base first inhibits and then poisons the catalyst. Lithium tert-butoxide performs very poorly, while even catalytic amounts of lithium additives also poison the catalyst. Meanwhile, a neopentane diol-based boron ester is required for best performance. As well as delivering this sought-after transformation, we have undertaken detailed mechanistic and computational investigations to probe the possible mechanism of the reaction and help explain the unexpected experimental observations.
- Tailor, Sanita B.,Manzotti, Mattia,Smith, Gavin J.,Davis, Sean A.,Bedford, Robin B.
-
p. 3856 - 3866
(2021/04/07)
-
- Coupling of Reformatsky Reagents with Aryl Chlorides Enabled by Ylide-Functionalized Phosphine Ligands
-
The coupling of aryl chlorides with Reformatsky reagents is a desirable strategy for the construction of α-aryl esters but has so far been substantially limited in the substrate scope due to many challenges posed by various possible side reactions. This limitation has now been overcome by the tailoring of ylide-functionalized phosphines to fit the requirements of Negishi couplings. Record-setting activities were achieved in palladium-catalyzed arylations of organozinc reagents with aryl electrophiles using a cyclohexyl-YPhos ligand bearing an ortho-tolyl-substituent in the backbone. This highly electron-rich, bulky ligand enables the use of aryl chlorides in room temperature couplings of Reformatsky reagents. The reaction scope covers diversely functionalized arylacetic and arylpropionic acid derivatives. Aryl bromides and chlorides can be converted selectively over triflate electrophiles, which permits consecutive coupling strategies.
- Hu, Zhiyong,Wei, Xiao-Jing,Handelmann, Jens,Seitz, Ann-Katrin,Rodstein, Ilja,Gessner, Viktoria H.,Goo?en, Lukas J.
-
supporting information
p. 6778 - 6783
(2021/02/01)
-
- Highly Active Fe3O4@SBA-15@NHC-Pd Catalyst for Suzuki–Miyaura Cross-Coupling Reaction
-
A novel Pd-NHC functionalized magnetic Fe3O4@SBA-15@NHC-Pd was synthesized and used as an efficient heterogeneous catalyst in the Suzuki–Miyaura C–C bond formation reactions. The Fe3O4@SBA-15@NHC-Pd characterized by X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Fourier Transform Infrared (FTIR) spectroscopy, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy?(TEM), Energy Dispersive X-ray analysis (EDX), Thermogravimetric Analysis (TGA), Differential Thermal Analysis (DTA). The Inductively Coupled Plasma-Optical emission spectroscopy (ICP-OES)?analysis was used to determine the exact amount of Pd (0.33?wt%) in Fe3O4@SBA-15@NHC-Pd. The TEM images of the catalyst showed the existence of palladium nanoparticles immobilized in the catalyst's structure, while no reducing agent was used. The NHC moieties in the catalyst structure could be stabilize Pd(0) nanoparticles prevents agglomeration. The magnetic catalyst was effectively used in the Suzuki–Miyaura cross-coupling reaction of substituted phenylboronic acid derivatives with (hetero)aryl bromides in the presence of a K2CO3 at room temperature in aqueous media and magnetic catalyst could be simply extracted from the reaction mixture by an external magnet. Different aryl bromides were converted to coupled-products in excellent yields with spectacular TOFs values (up to 1,960,339?h?1); in the presence of 1?mg of Fe3O4@SBA-15@NHC-Pd catalyst (contains 3.1 × 10–6?mol% Pd) at room temperature in aqueous media. After reusability experiments, it is found that this catalyst was effectively used up to ten times in the reaction with almost consistent catalytic efficiency. A decrease in the activity of the 10th reused catalyst was found as 9%. Graphic Abstract: [Figure not available: see fulltext.]
- ?zdemir, ?smail,Akko?, Mitat,Alt?n, Serdar,Bu?day, Nesrin,Ya?ar, Sedat
-
-
- C(acyl)-C(sp2) and C(sp2)-C(sp2) Suzuki-Miyaura cross-coupling reactions using nitrile-functionalized NHC palladium complexes
-
Application of N-heterocyclic carbene (NHC) palladium complexes has been successful for the modulation of C-C coupling reactions. For this purpose, a series of azolium salts (1a-f) including benzothiazolium, benzimidazolium, and imidazolium, bearing a CN-substituted benzyl moiety, and their (NHC)2PdBr2 (2a-c) and PEPPSI-type palladium (3b-f) complexes have been systematically prepared to catalyse acylative Suzuki-Miyaura coupling reaction of acyl chlorides with arylboronic acids to form benzophenone derivatives in the presence of potassium carbonate as a base and to catalyse the traditional Suzuki-Miyaura coupling reaction of bromobenzene with arylboronic acids to form biaryls. All the synthesized compounds were fully characterized by Fourier Transform Infrared (FTIR), and 1H and 13C NMR spectroscopies. X-ray diffraction studies on single crystals of 3c, 3e and 3f prove the square planar geometry. Scanning Electron Microscopy (SEM), energy dispersive X-ray spectroscopy (EDS), metal mapping analyses and thermal gravimetric analysis (TGA) were performed to get further insights into the mechanism of the Suzuki-Miyaura cross coupling reactions. Mechanistic studies have revealed that the stability and coordination of the complexes by the CN group are achieved by the removal of pyridine from the complex in catalytic cycles. The presence of the CN group in the (NHC)Pd complexes significantly increased the catalytic activities for both reactions.
- ?akir, Sinem,Karabiyik, Hande,Kavukcu, Serdar Batikan,Rethinam, Senthil,Türkmen, Hayati
-
p. 37684 - 37699
(2021/12/09)
-
- Magnetite@MCM-41 nanoparticles as support material for Pd-N-heterocyclic carbene complex: A magnetically separable catalyst for Suzuki–Miyaura reaction
-
The Magnetite@MCM-41@NHC@Pd catalyst was obtained with Pd metal bound to the NHC ligand anchored to the surface of Fe3O4@MCM-41. It was characterized by Fourier transform infrared (FTIR) spectroscopy, transmission electron microscopy (TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), energy disperse X-ray analysis (EDX), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and scanning electron microscopy (SEM). The amount of Pd in the Magnetite@MCM-41@NHC@Pd was measure by inductively coupled plasma–optical emission spectroscopy (ICP-OES) analysis. The catalytic activity of Magnetite@MCM-41@NHC@Pd heterogeneous catalyst done on Suzuki–Miyaura reactions of aryl halides with different substituted arylboronic acid derivatives. All coupling reactions afforded excellent yields and up to 408404 Turnover Frequency (TOF) h?1 in the presence of 2 mg of Magnetite@MCM-41@NHC@Pd catalyst (0.0564 mmol g?1, 0.01127 mmol% Pd) at room temperature in 2-propanol/H2O (1:2). Moreover, Magnetite@MCM-41@NHC@Pd catalyst was recover by applying the magnet and reused for another reaction. The catalyst showed excellent structural and chemical stability and reused ten times without a substantial loss in its catalytic performance.
- Akko?, Mitat,Bu?day, Nesrin,Alt?n, Serdar,Ya?ar, Sedat
-
-
- N-heterocyclic carbene Pd(II) complex supported on Fe3O4@SiO2: Highly active, reusable and magnetically separable catalyst for Suzuki-Miyaura cross-coupling reactions in aqueous media
-
A new type magnetic nano Fe3O4@SiO2@NHC@Pd-MNPs heterogeneous catalyst was fabricated and characterized by Fourier Transform Infrared (FTIR) spectroscopy, Transmission Electron Microscopy (TEM), X-Ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Energy Disperse X-ray analysis (EDX), Thermogravimetric Analysis (TGA), Differential Thermal Analysis (DTA), and Scanning Electron Microscopy (SEM). The loading amount of Palladium (Pd) to magnetic nano Fe3O4@SiO2@NHC@Pd-MNPs was measured by Inductively Coupled Plasma-Optical Emission Spectroscopy (ICP-OES) analysis. The catalytic activity of magnetic nano Fe3O4@SiO2@NHC@Pd-MNPs heterogeneous catalyst was examined on Suzuki-Miyaura cross-coupling reactions of aryl halides with different substituted arylboronic acid derivatives. All coupling reactions yielded excellent results and high TOF (up to 76528 h?1) in the presence of 2 mg of Fe3O4@SiO2@NHC@Pd-MNPs catalyst (0.0197 mmolg?1, 0.00394 mmol%Pd) at 80 °C in 2-propanol/H2O (1:2). In addition, the magnetic nano Fe3O4@SiO2@NHC@Pd-MNPs catalyst was easily recovered by using an external Nd-magnet and reused for the Suzuki cross-coupling reactions. The catalyst showed strong structural and chemical stability and was reused six times without losing its catalytic activity substantially.
- Akko?, Mitat,Bu?day, Nesrin,Alt?n, Serdar,Kiraz, Nadir,Ya?ar, Sedat,?zdemir, ?smail
-
-
- Palladium nanoparticle supported on nitrogen-doped porous carbon: Investigation of structural properties and catalytic activity on Suzuki–Miyaura reactions
-
Novel palladium-doped nanoporous carbon composite material obtained via thermolysis of amorphous zeolitic imidazolate framework (aZIF) was synthesized and used as an efficient catalyst on Suzuki–Miyaura cross-coupling reactions of aryl bromides. With this developed catalytic system, the Suzuki–Miyaura cross-coupling reaction was accomplished in aqueous solutions, and biaryls were obtained in good to excellent yields in a short reaction time. The APC-750@Pd catalyst was characterized by Fourier Transform Infrared spectroscopy (FTIR), X-ray Diffraction (XRD), Scanning Electron Eicroscopy (SEM), X-ray Photoelectron Spectroscopy (XPS), Transmission Electron Microscopy (TEM), Thermal Gravimetric Analysis (TGA), Differential Thermal Analysis (DTA), Inductively Coupled Plasma Mass Spectrometry (ICP-MS) and Brunauer–Emmett–Teller (BET) analysis tecniques. N-doped porous carbon material (NPC-1000) was synthesized by thermolysis from aZIF. Activated porous carbon material (APC-750) was fabricated via fused at 750°C with KOH from NPC-1000. The APC-750@Pd was obtained as a result of the interaction of APC-750 and PdCl2 in deionized water. The cross-coupling reaction of different aryl bromides with phenylboronic acid was investigated to show the potential of the APC-750@Pd in the Suzuki–Miyaura cross-coupling reactions. The APC-750@Pd catalyst could be recycled at least five times with a 15% loss of catalytic efficiency in this catalytic system.
- Bu?day, Nesrin,Alt?n, Serdar,Ya?ar, Sedat
-
-
- Suzuki-Miyaura coupling catalyzed by a Ni(II) PNP pincer complex: Scope and mechanistic insights
-
The nickel(II) pincer complex, [NiCl(PhPNP)] (PhPNP = anion of 2,5-bis(diphenylphosphinomethyl)pyrrole), has been employed as a precatalyst for the Suzuki-Miyaura cross-coupling reaction of aryl halides and boronic acids. Both electron-rich and electron-deficient aromatic bromides were found to undergo coupling with boronic acids in modest yield at elevated temperature in the presence of K3PO4·H2O. Preliminary mechanistic studies of the reaction identified a novel species formulated as the boronate complex, [Ni(OB{OH}{2-tolyl})(PhPNP)], which most likely represents a catalyst deactivation pathway. The productive catalytic cycle was found to be most consistent with a Ni(I)/Ni(III) process where the boronic acid serves as both reductant and nucleophile in the presence of base.
- Madera, Justin,Slattery, Megan,Arman, Hadi D.,Tonzetich, Zachary J.
-
-
- Bulky α-diimine palladium complexes supported graphene oxide as heterogeneous catalysts for Suzuki-Miyaura reaction
-
To explore high efficiency of the Suzuki-Miyaura reactions, an easily prepared heterogeous palladium precatalysts bearing sterically bulky α-diimine was covalently supported on graphene oxide (GO). The characterization of supported palladium complex was discussed in detail. A simple and efficient protocol for Pd-catalyzed cross coupling was described, which revealed that the bulky α-diimine ligand is crucial to promote the CAr-CAr transformation. This immobilized system provides a straightforward access to a wide range of aryl bromides with excellent functional groups tolerance.
- Liang, Ying,Liu, Feng-Shou,Liu, Ning,Qiao, NiNa,Wang, ShaoHua
-
-
- Tetrabutylphosphonium 4-ethoxyvalerate as a biomass-originated media for homogeneous palladium-catalyzed Hiyama coupling reactions
-
The introduction of a biomass-derived ionic liquid into the Hiyama coupling reactions, which has been considered as a powerful tool for the synthesis of symmetrically and non-symmetrically substituted biaryl structures, could further control or even reduce the environmental impact of this transformation. It was shown that tetrabutylphosphonium 4-ethoxyvalerate, a γ-valerolactone-based ionic liquid, can be utilized as an alternative solvent to create carbon–carbon bonds between aryl iodides and functionalized organosilanes in the presence of 1?molpercent Pd under typical Hiyama conditions (130?°C, 24?h, tetrabutylammonium fluoride activator). A comparison of different ionic liquids was performed, and the effects of the catalyst precursor and the moisture content of the reaction mixture on the activity of the catalyst system were investigated. The functional group tolerance was also studied, resulting in 15 cross-coupling products (3a–o) with isolated yields of 45–72percent and excellent purity (' 98percent).
- Orha, László,Papp, ábrahám,Tukacs, József M.,Kollár, László,Mika, László T.
-
p. 4593 - 4598
(2020/07/28)
-
- Metal-free synthesis of biarenes via photoextrusion in di(tri)aryl phosphates
-
A metal-free route for the synthesis of biarenes has been developed. The approach is based on the photoextrusion of a phosphate moiety occurring upon irradiation of biaryl- A nd triaryl phosphates. The reaction involves an exciplex as the intermediate and it is especially suitable for the preparation of electron-rich biarenes.
- Qrareya, Hisham,Meazza, Lorenzo,Protti, Stefano,Fagnoni, Maurizio
-
p. 3008 - 3014
(2021/01/18)
-
- Small organic molecules with tailored structures: Initiators in the transition-metal-free C-H arylation of unactivated arenes
-
Simple, small organic molecules containing nitrogen and oxygen atoms in their structures have been disclosed to catalyze transition-metal-free C-H arylation of unactivated arenes with aryl iodides in the presence of tBuOK. In this article, an optimized catalytically active molecule, (2-(methylamino)phenyl)methanol, was designed. A broad range of aryl iodides could be converted into the corresponding arylated products at 100 °C over 24 h with good to excellent yields. Mechanistic experiments verified that radicals participated in this catalytic transformation and that the cleavage of the aromatic C-H bond was not the rate determining step. A K+ capture experiment by 18-crown-6 emphasized the significance of the cation species of the strong base. Fourier transform infrared spectroscopy proved that the catalytic system was activated by the hydrogen bonds between small organic molecules and tBuOK. Also, a clear mechanism was proposed. This transition-metal-free method affords a promising system for efficient and inexpensive synthesis of biaryls via a user-friendly approach, as confirmed by scale-up experiments.
- Chen, Suqing,Chen, Wenjun,Chen, Yu,Liu, Zhenghui,Mu, Tiancheng,Wang, Peng,Yan, Zhenzhong
-
p. 14500 - 14509
(2020/04/27)
-
- NHC-Nickel Catalyzed C-N Bond Cleavage of Mono-protected Anilines for C-C Cross-Coupling
-
A Ni-catalyzed aryl C-N bond cleavage of mono-protected anilines, N-arylsulfonamides, has been developed. A new N-heterocyclic carbene derived from benzoimidazole shows high reactivity for the C-N cleavage/C-C cross-coupling reaction. The ortho-directing group is not required to break the C-N bond of sulfonyl-protected anilines, which are not limited to π-extended anilines. The mechanistic studies have revealed that a sulfamidomagnesium salt is the key coupling intermediate.
- Xia, Ji-Bao,Zhang, Zheng-Bing
-
supporting information
p. 9609 - 9613
(2020/12/21)
-
- Spatial anion control on palladium for mild C-H arylation of arenes
-
C-H arylation of arenes without the use of directing groups is a challenge, even for simple molecules, such as benzene. We describe spatial anion control as a concept for the design of catalytic sites for C-H bond activation, thereby enabling nondirected C-H arylation of arenes at ambient temperature. The mild conditions enable late-stage structural diversification of biologically relevant small molecules, and site-selectivity complementary to that obtained with other methods of arene functionalization can be achieved. These results reveal the potential of spatial anion control in transition-metal catalysis for the functionalization of C-H bonds under mild conditions.
- Dhankhar, Jyoti,González-Fernández, Elisa,Dong, Chao-Chen,Mukhopadhyay, Tufan K.,Linden, Anthony,?ori?, Ilija
-
p. 19040 - 19046
(2020/11/13)
-
- Palladium-Catalyzed Amide N-C Hiyama Cross-Coupling: Synthesis of Ketones
-
N-Acylglutarimides and arylsiloxanes reacted in the presence of Pd(OAc)2/PCy3, Et3N·3HF, and LiOAc to provide the corresponding arylketones in good yields. Aryl-, vinyl-, and alkyl-substituted N-acylglutarimides showed good activity in the coupling reactions of arylsiloxanes. The reaction had a broad substrate scope and showed good functional group tolerance. N-Benzoylsuccinimide and N-protected N-phenylbenzamides showed good activities in coupling reactions with phenylsiloxane. The employment of CuF2 as an activor afforded the decarbonylative products at 160 °C.
- Idris, Muhammad Aliyu,Lee, Sunwoo
-
supporting information
p. 9190 - 9195
(2020/11/18)
-
- Synthesis of Biaryls via Decarbonylative Nickel-Catalyzed Suzuki-Miyaura Cross-Coupling of Aryl Anhydrides
-
Transition metal-catalyzed cross-couplings have been widely employed in the synthesis of many important molecules in synthetic chemistry for the construction of diverse C-C bonds. Conventional cross-coupling reactions require active electrophilic coupling partners, such as organohalides or sulfonates, which are not environmentally friendly enough. Herein, we disclose the first nickel-catalyzed Suzuki-Miyaura cross-coupling of aryl anhydrides and arylboronic acids for the synthesis of biaryls in a decarbonylation manner. The reaction tolerates a wide range of electron-withdrawing, electron-neutral, and electron-donating substituents in this process.
- Zhou, Jing-Ya,Liu, Rui-Qing,Wang, Cheng-Yi,Zhu, Yong-Ming
-
p. 14149 - 14157
(2020/11/13)
-
- Boracene-based alkylborate enabled Ni/Ir hybrid catalysis
-
Boracene-based alkylborate enabled visible light-mediated metallaphotoredox catalysis. The directly excited borate was easily oxidatively quenched by an excited Ir photoredox catalyst. Ni/Ir hybrid catalysis afforded the products under significantly low i
- Hosoya, Takamitsu,Miyamoto, Yusuke,Ohmiya, Hirohisa,Sato, Yukiya,Sumida, Yuto
-
supporting information
p. 6598 - 6601
(2020/10/02)
-
- Suzuki-Miyaura Cross-Coupling of Sulfoxides
-
The utilization of diphenyl sulfoxides as versatile electrophilic coupling partners for the Suzuki-Miyaura reaction via C-S bond cleavage was successfully developed under palladium-N-heterocyclic carbene catalysis. The reactions showed good functional group compatibility, proceeded well under mild conditions, and provided biaryls in yields of up to 96%. A wide range of useful functional groups, such as fluoro, chloro, ether, hydroxyl, amide, cyano, keto, trimethylsilyl (TMS), and ester were tolerated under the reaction conditions; however, the use of phenylboronic anhydride and arylboronic acid pinacol esters generally would lead low yields. Good regioselectivity for the electron-poor phenyl group was achieved when unsymmetrical diphenyl sulfoxides were used. The protocol is applicable at the gram scale even with half the amount of catalyst. Density functional theory calculations were performed to investigate the reaction mechanism, indicating that the reaction occurred through oxidative addition, transmetalation, and reductive elimination to provide the final coupling product.
- Abduhulam, Hayrul,Cao, Changsheng,Chen, Qianwei,Dang, Yanfeng,Li, Chengxi,Shi, Yanhui,Wu, Shufeng,Yan, Shuqin
-
p. 8168 - 8176
(2020/09/18)
-
- Transition-Metal-Free Oxidative Cross-Coupling of Tetraarylborates to Biaryls Using Organic Oxidants
-
Readily prepared tetraarylborates undergo selective (cross)-coupling through oxidation with Bobbitt's salt to give symmetric and unsymmetric biaryls. The organic oxoammonium salt can be used either as a stoichiometric oxidant or as a catalyst in combination with in situ generated NO2 and molecular oxygen as the terminal oxidant. For selected cases, oxidative coupling is also possible with NO2/O2 without any additional nitroxide-based cocatalyst. Transition-metal-free catalytic oxidative ligand cross-coupling of tetraarylborates is unprecedented and the introduced method provides access to various biaryl and heterobiaryl systems.
- Gerleve, Carolin,Studer, Armido
-
supporting information
p. 15468 - 15473
(2020/05/06)
-
- Generation of Alkyl Radical through Direct Excitation of Boracene-Based Alkylborate
-
The generation of tertiary, secondary, and primary alkyl radicals has been achieved by the direct visible-light excitation of a boracene-based alkylborate. This system is based on the photophysical properties of the organoboron molecule. The protocol is applicable to decyanoalkylation, Giese addition, and nickel-catalyzed carbon-carbon bond formations such as alkyl-aryl cross-coupling or vicinal alkylarylation of alkenes, enabling the introduction of various C(sp3) fragments to organic molecules.
- Hashizume, Daisuke,Hosoya, Takamitsu,Nakamura, Kei,Ohmiya, Hirohisa,Sato, Yukiya,Sumida, Yuto
-
supporting information
p. 9938 - 9943
(2020/06/27)
-
- Design, synthesis and application of triazole ligands in suzuki miyaura cross coupling reaction of aryl chlorides
-
DFT calculations have been demonstrated to be a valuable tool for the mechanistic study of reaction which is difficult to acquire from pure experimental techniques. Structural, electronic and coordination aspects of synthesized triazole ligands were investigated theoretically by structure optimization on Gaussian 09 package by DFT approach at B3LYP/6-31G (d, p). HOMO-LUMO energy gaps correlated to its chemical reactivity and this information applied to interpret the role of ligand in the formation of ligand-metal complex. Electron rich environment around the triazole core stabilized the HOMO orbital and made these electrons available to form complex with Pd centre. The DFT calculations provide a plausible mechanism for the reaction that is consistent with the available experimental facts. A series of triazole ligands have been synthesized via efficient 1,3-dipolar cycloaddition of readily available azide and alkynes for coordination to Pd centre. Characterization of all the synthesized compounds was done by FTIR, 1H NMR, 13C NMR and HRMS. Their ligand-Pd complexes provided excellent yields in the Suzuki-Miyaura coupling reactions (up to 92% yield) of unactivated aryl chlorides. Ligand 4-(2,6-dimethoxyphenyl)-1-phenyl-1H-1,2,3-triazole (L2) was found to be most effective ligand because of electron donating 2,6 dimethoxy phenyl moiety attached to triazole ring at 4-position that facilitated the formation of electron rich ligand-catalyst complex. The complex favoured the oxidative addition step of Pd across the aryl chloride substrate and thus allowed for the development of highly active ligand-catalyst system for Suzuki reaction. During computational analysis, 4-(2,6-dimethoxyphenyl)-1-phenyl-1H-1,2,3-triazole (L2) also showed lowest band gap due to electron rich distribution pattern on the HOMO that are involve in ligand-Pd complex formation. Conclusively, these triazoles ligands were found to be more competent and attractive for palladium catalyst because of simplistic pathway for the synthesis of triazole motif and the ease of individual tuning of the substituents on triazole core or exocyclic to it.
- Jabeen, Sobia,Khera, Rasheed Ahmad,Iqbal, Javed,Asgher, Muhammad
-
-
- N-Heterocyclic Carbene–Palladium Complex onto Graphene Oxide and Poly (ethylene glycol) (PEG) Applied as Superior Catalyst for the Suzuki-Miyaura Cross-Coupling Reaction in Water
-
Using polymeric nanocomposites incorporated Pd to promote C-C coupling reactions has been found as one of the most successful strategies. In this paper we apply graphene oxide (GO) as an efficient surface immobilized by water-soluble poly (ethylene glycol)-imidazole followed by introduction of PdCl2 salt to obtain the desired catalyst. Catalytic performance of this composite was investigated in the Suzuki–Miyaura cross-coupling reaction under mild reaction conditions and superior results were obtained. The hydrophilic nature of the catalyst and well distribution of Pd lead to superior catalytic activity in water media. Moreover, the Suzuki–Miyaura reaction proceed successfully with excellent yield and short reaction time without any loss of activity even after seven consecutive reaction cycles.
- Heravi, Majid M.,Asadi, Shima,Hoseini Chopani, Seyede Mahdiye,Jaderi, Elham
-
-
- Ligand-free Suzuki coupling reaction with highly recyclable ionic palladium catalyst, Ti1-xPdxO2-x (x?=?0.03)
-
We synthesized a recyclable palladium ionic catalyst, Ti0.97Pd0.03O1.97, using a solution combustion method (SCM), and characterized by XRD and Rietveld refinement. The synthesized Pd ionic catalyst is stable, insensitive to moisture and air, and easy to handle. The new catalyst has exhibited a phenomenal result for the Suzuki-Miyaura cross-coupling reaction with a broad substrate scope, and the reaction proceeds in an aqueous medium. The new catalyst proved beneficial and produced excellent yields irrespective of aryl halide used in the reaction (electron-rich or electron-poor or heterocyclic compounds) and shown a turnover frequency (TOF) of 14–25 h?1 for different reactions. The catalyst was coated on a cordierite monolith (Mg2Al4Si5O18), which enhanced the applicability of the catalyst, and made the handling and recycling of the catalyst very easy. Suzuki Miyaura reaction was carried out using both Pd-powder catalysts as well as the Pd-coated honeycomb, which gave almost similar results. We have demonstrated the recyclability of Pd coated cordierite monolith and shown the superiority of the catalyst over the other Pd catalysts for the Suzuki-Miyaura reaction.
- Bhat K, Shrikanth,Lanke, Veeranjaneyulu,Prasad, Jagadeesh Dasappa,Prabhu, Kandikere Ramaiah
-
-
- Magnetite tethered mesoionic carbene-palladium (II): An efficient and reusable nanomagnetic catalyst for Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions in aqueous medium
-
In this paper, a highly active, air- and moisture-stable and easily recoverable magnetic nanoparticles tethered mesoionic carbene palladium (II) complex (MNPs-MIC-Pd) as nanomagnetic catalyst was successfully synthesized by a simplistic multistep synthesis under aerobic conditions using commercially available inexpensive chemicals for the first time. The synthesized MNPs-MIC-Pd nanomagnetic catalyst was in-depth characterized by numerous physicochemical techniques such as FT-IR, ICP-AES, FESEM, EDS, TEM, p-XRD, XPS, TGA and BET surface area analysis. The prepared MNPs-MIC-Pd nanomagnetic catalyst was used to catalyze the Suzuki–Miyaura and Mizoroki–Heck cross-coupling reactions and exhibited excellent catalytic activity for various substrates under mild reaction conditions. Moreover, MNPs-MIC-Pd nanomagnetic catalyst could be easily and rapidly recovered by applying an external magnet. The recovered MNPs-MIC-Pd nanomagnetic catalyst exhibited very good catalytic activity up to ten times in Suzuki–Miyaura and five times in Mizoroki–Heck cross-coupling reactions without considerable loss of its catalytic activity. However, MNPs-MIC-Pd nanomagnetic catalyst shows notable advantages such as heterogeneous nature, efficient catalytic activity, mild reaction conditions, easy magnetic work up and recyclability.
- Kempasiddhaiah, Manjunatha,Kandathil, Vishal,Dateer, Ramesh B.,Sasidhar, Balappa S.,Patil, Shivaputra A.,Patil, Siddappa A.
-
-
- Application of zwitterionic phosphapalladacycles in aqueous phase Suzuki-Miyaura coupling
-
The catalytic application of novel six-membered zwitterionic palladacycles with formal negative charge on the metal center and positive charge on the ancillary ligand is reported in the aqueous phase Suzuki-Miyaura coupling. The novel catalysts provide excellent activities with high functional group tolerance in the carbon-carbon bond forming reaction yielding substituted biaryls in high yields.
- Szi-Ferenc, László,Császár, Zsófia,Bényei, Attila,Bakos, József,Farkas, Gergely
-
supporting information
p. 569 - 570
(2019/01/04)
-
- From agriculture residue to catalyst support; A green and sustainable cellulose-based dip catalyst for C–C coupling and direct arylation
-
The core characteristics of a perfect catalyst include good activity, simple design, excellent stability, easy recovery from reaction mixture, recyclability, and have the provision for easy scale up. The ease in synthesis, recyclability and scale up makes the dip catalyst a major contender in this regard which possess most of the aforementioned characteristics. In this work, we report a dip catalyst made of cellulose, isolated from agriculture residue (sugarcane bagasse), in which biogenically synthesized palladium nanoparticles were dispersed. The prepared dip catalyst was characterized by FESEM, EDS, XRD, ATR-IR, TGA, TEM, XPS and ICP-OES analysis. Also, the activity of the dip catalyst was studied in the Suzuki-Miyaura cross-coupling reaction and was found to give excellent conversion with 15 recycles. Further, the activity of dip catalyst in C5-arylation of 2-substituted thiophenes was evaluated for which promising yields were obtained.
- Kandathil, Vishal,Kempasiddaiah, Manjunatha,B. S., Sasidhar,Patil, Siddappa A.
-
-
- Convenient and efficient Suzuki–Miyaura and Heck–Mizoroki cross-coupling reactions catalyzed by 1,3,4-trisubstituted-1,2,3-triazolium iodide and palladium salt systems
-
A series of 1,3,4-trisubstituted-1,2,3-triazolium iodide salts (4a–c) were synthesized via a three-step reaction sequence. Corresponding anilines (1a–c) were converted to azides (2a–c) which were then treated with phenylacetylene with “Click” chemistry to access 1,4-disubstituted-1,2,3-triazoles (3a–c). Subsequent methylation of 1,4-disubstituted-1,2,3-triazoles (3a–c) yielded 1,3,4-trisubstituted-1,2,3-triazoliumiodide salts (4a–c) in appreciable yields. All the synthesized compounds were characterized by 1H and 13C NMR, ATR–IR spectroscopic techniques and elemental analyses. Additionally, the structure of 1-(4-chlorophenyl)-4-phenyl-1,2,3-triazole (3b) was confirmed by single crystal X-ray diffraction analysis. The catalytic activity of 4a–c in a catalytic system consisting of 1,3,4-trisubstituted-1,2,3-triazoliumiodide salt/palladium(II) acetate/base were investigated toward Suzuki–Miyaura and Heck–Mizoroki cross-coupling reactions. The Suzuki–Miyaura cross-coupling reactions were carried out under mild reaction conditions with good to excellent yields, whereas Heck–Mizoroki cross-coupling reactions were performed at elevated temperature with moderate yields. Further, in situ method skips the synthetic procedure of preparing the palladium(II) complexes and hence is more economical and less tedious. (Figure presented.).
- Shahini,Achar, Gautam,Budagumpi, Srinivasa,Dateer, Ramesh B.,Müller-Bunz, Helge,Tacke, Matthias,Patil, Siddappa A.
-
p. 528 - 549
(2019/02/26)
-
- A Bipyridine-Palladium Derivative as General Pre-Catalyst for Cross-Coupling Reactions in Deep Eutectic Solvents
-
A versatile and DES-compatible bipyridine palladium complex has been developed as a general pre-catalyst for different cross-coupling reactions (Hiyama, Suzuki-Miyaura, Heck-Mizoroki and Sonogashira) in deep eutectic solvents. Hydrogen bond capacity of the ligand allows to keep the excellent level of results previously obtained in classical organic solvents. Palladium pre-catalyst showed a high catalytic activity for many cross-coupling reactions, demonstrating a great versatility and applicability. Also, this methodology employs sustainable solvents as a reaction medium and highlights the potential of DES as alternative solvents in organometallic catalysis. The catalyst and DES were easily and successfully recycled. The formation of PdNPs in DES has been confirmed by TEM and XPS analysis and their role as catalyst by mercury test. The dynamic coordination of bipyridine-type ligand in the palladium complex formation has been studied via UV/Vis. (Figure presented.).
- Saavedra, Beatriz,González-Gallardo, Nerea,Meli, Alessandro,Ramón, Diego J.
-
supporting information
p. 3868 - 3879
(2019/07/12)
-
- Transition-Metal-Free C-C, C-O, and C-N Cross-Couplings Enabled by Light
-
Transition-metal-catalyzed cross-couplings to construct C-C, C-O, and C-N bonds have revolutionized chemical science. Despite great achievements, these metal catalysts also raise certain issues including their high cost, requirement of specialized ligands, sensitivity to air and moisture, and so-called "transition-metal-residue issue". Complementary strategy, which does not rely on the well-established oxidative addition, transmetalation, and reductive elimination mechanistic paradigm, would potentially eliminate all of these metal-related issues. Herein, we show that aryl triflates can be coupled with potassium aryl trifluoroborates, aliphatic alcohols, and nitriles without the assistance of metal catalysts empowered by photoenergy. Control experiments reveal that among all common aryl electrophiles only aryl triflates are competent in these couplings whereas aryl iodides and bromides cannot serve as the coupling partners. DFT calculation reveals that once converted to the aryl radical cation, aryl triflate would be more favorable to ipso substitution. Fluorescence spectroscopy and cyclic voltammetry investigations suggest that the interaction between excited acetone and aryl triflate is essential to these couplings. The results in this report are anticipated to provide new opportunities to perform cross-couplings.
- Liu, Wenbo,Li, Jianbin,Querard, Pierre,Li, Chao-Jun
-
p. 6755 - 6764
(2019/05/06)
-
- Involving Single-Atom Silver(0) in Selective Dehalogenation by AgF under Visible-Light Irradiation
-
The dehalogenation-arylation and the hydrodehalogenation of various types of organic halides are selectively realized using AgF and visible light without any organic additives under mild conditions. Single-atom silver(0) (denoted as SAAg) serves as the catalytically active center, and the TOF of SAAg reaches 6000 h-1. This elusive activity of Ag is beyond that expected from its ionic, nano, or bulk forms.
- Wu, Wenli,Cui, Enxin,Zhang, Yun,Zhang, Chen,Zhu, Feng,Tung, Chen-Ho,Wang, Yifeng
-
p. 6335 - 6341
(2019/07/04)
-
- Palladium-catalyzed decarbonylative Suzuki-Miyaura cross-coupling of amides by carbon-nitrogen bond activation
-
Palladium-catalyzed Suzuki-Miyaura cross-coupling or aryl halides is widely employed in the synthesis of many important molecules in synthetic chemistry, including pharmaceuticals, polymers and functional materials. Herein, we disclose the first palladium-catalyzed decarbonylative Suzuki-Miyaura cross-coupling of amides for the synthesis of biaryls through the selective activation of the N-C(O) bond of amides. This new method relies on the precise sequence engineering of the catalytic cycle, wherein decarbonylation occurs prior to the transmetallation step. The reaction is compatible with a wide range of boronic acids and amides, providing valuable biaryls in high yields (>60 examples). DFT studies support a mechanism involving oxidative addition, decarbonylation and transmetallation and provide insight into high N-C(O) bond activation selectivity. Most crucially, the reaction establishes the use of palladium catalysis in the biaryl Suzuki-Miyaura cross-coupling of the amide bond and should enable the design of a wide variety of cross-coupling methods in which palladium rivals the traditional biaryl synthesis from aryl halides and pseudohalides.
- Zhou, Tongliang,Ji, Chong-Lei,Hong, Xin,Szostak, Michal
-
p. 9865 - 9871
(2019/11/11)
-
- Visible-Light-Induced [4+2] Annulation of Thiophenes and Alkynes to Construct Benzene Rings
-
The [4+2] annulation represents an elegant and versatile synthetic protocol for the construction of benzene rings. Herein, a strategy for visible-light induced [4+2] annulation of thiophenes and alkynes, to afford benzene rings, is presented. Under simple and mild reaction conditions, the ready availability and structural diversity of thiophenes and alkynes permit the facile synthesis of several substituted aromatic rings. Valuable drugs and amino acids are also well tolerated. Moreover, DFT calculations explain the high regioselectivity of the reaction.
- Song, Chunlan,Dong, Xin,Wang, Zhongjie,Liu, Kun,Chiang, Chien-Wei,Lei, Aiwen
-
supporting information
p. 12206 - 12210
(2019/07/31)
-
- Synthesis of Triazole Click Ligands for Suzuki-Miyaura Cross-Coupling of Aryl Chlorides
-
A series of new triazole ligands has been synthesized via copper-catalyzed cycloaddition reaction of readily available azides and alkynes. The synthesized compounds were characterized by FTIR, 1H and 13C NMR, and high-resolution mass spectra. The ligands provided excellent yields (up to 92%) in the palladium-catalyzed Suzuki-Miyaura cross coupling of unactivated aryl chlorides with phenylboronic acid. 1-Benzyl-4-(2,6-dimethoxyphenyl)-lH-1,2,3-triazole was found to be the most effective ligand due to the presence of electron-donating 2,6-dimethoxyphenyl substituent, which made it possible to develop a highly active ligand-catalyst system for the Suzuki reaction of aryl chlorides.
- Jabeen,Khera,Iqbal,Asgher
-
p. 1416 - 1422
(2019/11/03)
-
- Ligand-free nickel-catalyzed Kumada couplings of aryl bromides with tert-butyl Grignard reagents
-
A ligand-free nickel-catalyzed Kumada cross-coupling of aryl bromides and tert-butyl Grignard reagents led to the formation of a series of tert-butyl aryls in moderate to good yields, excellent tBu/iBu ratios, and good functional group compatibility. A radical coupling process is indicated and a mechanism with a Ni(I)-Ni(III) catalytic cycle is proposed.
- Wu, Zhenghan,Si, Tengda,Xu, Guangqing,Xu, Bin,Tang, Wenjun
-
supporting information
p. 597 - 600
(2019/01/05)
-
- Indolylbenzimidazole-based ligands catalyze the coupling of arylboronic acids with aryl halides
-
A novel class of compounds bearing indole and benzimidazole rings was designed and easily synthesized from 2-indolecarboxylic acid and o-phenylenediamine. The catalytic system derived from a 2-indolylbenzimidazole-based ligand and Pd(OAc)2 in situ could lead to complete conversion of aryl bromides at 0.5?mol% Pd loading under mild reaction conditions. In the presence of a catalyst, sterically hindered biaryls were selectively generated in excellent yields by adjusting reaction parameters through the coupling of arylboronic acids with aryl halides. The efficiency of this reaction was demonstrated by its compatibility with various functional groups.
- Wang, Meng-Pei,Chiu, Chien-Cheng,Lu, Ta-Jung,Lee, Dong-Sheng
-
-
- An efficient class of bis-NHC salts: Applications in Pd-catalyzed reactions under mild reaction conditions
-
This study describes an efficient class of bis-N-heterocyclic carbene (bis-NHC) salts that can be easily made from commercially available and inexpensive starting materials. The application of these salts to Pd-catalyzed reactions is described. The palladium (Pd) catalyst generated in situ was highly effective under mild reaction conditions.
- Chiu, Chien-Cheng,Chiu, Hui-Tzu,Lee, Dong-Sheng,Lu, Ta-Jung
-
p. 26407 - 26415
(2018/08/04)
-
- Bis-benzimidazolium-palladium system catalyzed Suzuki-Miyaura coupling reaction of aryl bromides under mild conditions
-
Bis-benzimidazolium salts were prepared successfully from commercially available and inexpensive o-phenylenediamine through a series of simple reactions. The bis-NHC-Pd complexes prepared in situ can catalyze Suzuki-Miyaura cross-coupling reaction under very mild conditions in aqueous media with excellent yields. The efficiency of this reaction is demonstrated by its compatibility with a range of functional groups. Di-ortho-substituted biaryls could be accomplished in 89–99% yields. Moreover, the rigorous exclusion of air or moisture is not required in these transformations.
- Lin, Yi-Rang,Chiu, Chien-Cheng,Chiu, Huai-Tsu,Lee, Dong-Sheng,Lu, Ta-Jung
-
-