- Preparation, structure and catalytic properties of a binuclear Pd(0) complex with bridging silylene ligands
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In contrast to the N-heterocyclic carbene (NHC) 1, the homologous N-heterocyclic silylene (NHS) 4 acts as a bridging ligand to Pd(0), giving rise to the dinuclear complex 5 which is catalytically active in Suzuki reactions.
- Fuerstner,Krause,Lehmann
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- Biaryl Coupling of Aryldiazonium Salts and Arylboronic Acids Catalysed by Gold
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A gold-catalysed coupling of aryldiazonium salts with arylboronic acids is described. The reactions proceed in satisfactory yields under irradiation with blue LEDs in the presence of KF and a catalytic amount of ascorbic acid. Notably, 4-nitrobenzendiazonium tetrafluoroborate is sufficiently reactive to undergo the coupling with a variety of arylboronic acids in the absence of aryl radical initiators. The coupling is applicable for electron-donating and electron-withdrawing groups present at the para, ortho, and meta positions of both substrates.
- Medina-Mercado, Ignacio,Porcel, Susana
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- Preparation and characterization of Cu based on 2-(5-Aminopyrimidin-2-yl)pyrimidin-5-amine as novel recyclable metal–organic frameworks for Suzuki reaction
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For first time, in this work, a new, heterogeneous and recyclable catalyst was designed using immobilizing Cu on 2-(5-Aminopyrimidin-2-yl)pyrimidin-5-amine ([CuAPPA·2H2O]n) named metal–organic frameworks (MOFs). This catalyst was used for the synthesis of biaryl derivatives by Suzuki reaction. Suzuki reaction performed with mixing of the aryl halides with arylboronic acids in the DMF solvent conditions. Also, the prepared catalyst was characterized with different analytical techniques such as FT-IR, XRD, SEM, EDX, BET and ICP-AES analysis. [CuAPPA·2H2O]n catalyst displayed good to excellent yields catalytic efficiency for Suzuki reaction in comparison with to other catalysts. Also, the recoverability and reusability related to this catalyst was checked by a simple filtration with reserving its activity even after several cycles.
- Mohammadnia, Majid
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- 'Awaken' aryl sulfonyl fluoride: a new partner in the Suzuki-Miyaura coupling reaction
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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
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p. 3560 - 3564
(2022/03/07)
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- Preparation of Functionalized Diorganomagnesium Reagents in Toluene via Bromine or Iodine/Magnesium-Exchange Reactions
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A wide range of polyfunctionalized di(hetero)aryl- and dialkenyl-magnesium reagents are prepared in toluene within 10 to 120 minutes between 78 C and 25 C via an I/Mg- or Br/Mg-exchange reaction using reagents of the general formula R2Mg (R = sBu, Mes). Highly sensitive functional groups, such as triazene or nitro, are tolerated in these exchange reactions, enabling the synthesis of various functionalized (hetero)arene and alkene derivatives after quenching with several electrophiles including allyl bromides, acyl chlorides, aldehydes, ketones, and aryl iodides.
- Desaintjean, Alexandre,Danton, Fanny,Knochel, Paul
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supporting information
p. 4461 - 4476
(2021/08/13)
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- Pd Nanoparticles Embedded Into MOF-808: Synthesis, Structural Characteristics, and Catalyst Properties for the Suzuki–Miyaura Coupling Reaction
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Abstract: A heterogeneous single-site catalyst Pd@MOF-808 was successfully synthesized by water-based, green synthesis procedure. The catalytic experiments exhibited the Pd@MOF-808 promoted efficiently the Suzuki–Miyaura coupling reaction without the assistance of organic phosphine ligands at atmospheric pressure conditions. The catalyst also could be applied in the gram-scale synthesis of industrially anti-inflanmatory analgestic Fenbufen. Graphic Abstract: [Figure not available: see fulltext.]
- Li, Tang,Pang, Wan,Wang, Jie,Zhang, Xiaoli,Zhao, Zesheng
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- Magnetic chitosan-functionalized cobalt-NHC: Synthesis, characterization and catalytic activity toward Suzuki and Sonogashira cross-coupling reactions of aryl chlorides
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Aryl chlorides are one of the most stable and available electrophiles, however, their coupling with nucleophiles remains a challenge in organic synthesis. Herein, we prepared a Cobalt-NHC (N-Heterocyclic carbene) complex anchored on magnetic chitosan nanoparticles and assayed its catalytic activity for the reactions of substituted phenylboronic acid and also phenlacetylene with derivatives of aryl chlorides. These reactions are of great importance since they are employed for the synthesis of unsymmetrical diarylethynes and biphenyls, which belong to a prime class of building blocks. The synthesized nanocatalyst was found to be highly efficient in Suzuki and Sonogashira coupling in terms of their activity and recyclability in polyethylene glycol (PEG) as a green reaction media under conditions of temperatures (70 and 100 °C) and Co loading (3 and 6 mol%). To the best of our knowledge, this is the first attempt of using cobalt-NHC complex for catalyzing the abovementioned reactions. Moreover, replacing the earth-abundant Cobalt-based catalyst as an alternative to high cost palladium make this approach promising from sustainable chemistry view.
- Hajipour, Abdol R.,Malek, Shaghayegh Sadeghi
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- Complexes LNi(Cp)X with alkylamino-substituted N-heterocyclic carbene ligands (L) and their catalytic activity in the Suzuki—Miyaura reaction
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New nickel(ii) complexes of the general formula LNi(Cp)X (L is an N-heterocyclic carbene (NHC) ligand of the 1,2,4-triazole or imidazole series; Cp is the cyclopentadienyl anion; X = Cl, I) are reported. In these complexes, the NHC ligands (L) contain an alkylamino group at the 3 or 4 position of the heterocycle. The synthesized complexes and structurally similar complexes without an alkylamino group were tested for catalytic activity in the Suzuki—Miyaura reaction. The introduction of an alkylamino group into the NHC ligand leads to the enhancement of the catalytic activity of complexes with N,N′-diaryl-substituted NHC ligands of the imidazole series and a decrease in the activity of the complexes with N,N′-dialkyl-substituted NHC ligands of the 1,2,4-triazole series.
- Chernyshev, V. M.,Chesnokov, V. V.,Shevchenko, M. A.,Soliev, S. B.,Tafeenko, V. A.
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p. 1281 - 1289
(2021/08/10)
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- A comparative study of catalytic activity on iron-based carbon nanostructured catalysts with Pd loading: Using the Box–Behnken design (BBD) method in the Suzuki–Miyaura coupling
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Highly dispersed palladium nanoparticles immobilized on surface-modified Fe3O4 NPs and magnetic carbon nanostructures (CNSs; carbon nanotubes/graphene oxide) were synthesized and applied as a recyclable and reusable nanocatalyst to achieve palladium (II)-catalyzed Suzuki–Miyaura reaction of arylboronic acid with aryl bromides. Carbon nanostructures with immobilized hydantoin (PH)-Pd complex display excellent stability, including a high performance at low catalyst loading. Magnetic separation prevents catalyst centrifuge or filtration and also contributes to practical techniques for recovery. Next, a response surface method based on a three-level Box–Behnken design was used, which involved three factors: catalyst loading, reaction time, and solvent. The Box–Behnken method was advantageous to parameters optimization for obtaining a yield, with high efficiency and accuracy. As a result of catalytic tests, the TONs and TOFs were calculated from all coupling reactions. The prepared nano-magnetic catalysts, after the catalysis reaction, can be easily recovered through the magnetic field. Evaluated catalytic performance indicates that these types of catalysts can function as effective recyclable catalysts at least five times without losing the initial level of catalytic activity.
- Moniriyan, Faezeh,Sabounchei, Seyyed Javad
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- Desulfonative Suzuki–Miyaura Coupling of Sulfonyl Fluorides
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Sulfonyl fluorides have emerged as powerful “click” electrophiles to access sulfonylated derivatives. Yet, they are relatively inert towards C?C bond forming transformations, notably under transition-metal catalysis. Here, we describe conditions under which aryl sulfonyl fluorides act as electrophiles for the Pd-catalyzed Suzuki–Miyaura cross-coupling. This desulfonative cross-coupling occurs selectively in the absence of base and, unusually, even in the presence of strong acids. Divergent one-step syntheses of two analogues of bioactive compounds showcase the expanded reactivity of sulfonyl fluorides to encompass both S?Nu and C?C bond formation. Mechanistic experiments and DFT calculations suggest oxidative addition occurs at the C?S bond followed by desulfonation to form a Pd-F intermediate that facilitates transmetalation.
- Bahadori, Maryam,Brykczyńska, Daria,Chatelain, Paul,Moran, Joseph,Muller, Cyprien,Rowley, Christopher N.,Sau, Abhijit
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supporting information
p. 25307 - 25312
(2021/10/25)
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- Heterogeneous Fe3O4@Si–NHC–Pd Catalyst: Synthesis, Characterization, and Catalytic Activity in the Suzuki–Miyaura Cross-Coupling Reaction under Mild Conditions
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Abstract: A novel Fe3O4@Si–NHC–Pd catalystwith N-heterocyclic carbenes (NHCs) moiety as an alternative ligand tophosphines for metal complexes has been synthesized and characterized by variousmethods. Synthesis of metal nanoparticles has been accomplished withoutaggregation, and the prepared catalyst has been applied in theSuzuki–Miyauracross-coupling reaction of boronic acids and aryl halides in water usingEt3N as a base. The catalyst has demonstrated highefficiency at room temperature and can be easily removed from the reaction mediausing an external magnetic field and recycled at least five times withoutsignificant decrease of its activity.
- Kalishomi, R. Ghavidel,Rostamizadeh, S.
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p. 1140 - 1146
(2021/08/06)
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- Suzuki coupling reactions catalyzed by Schiff base supported palladium complexes bearing the vitamin B6 cofactor
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Novel Schiff bases were synthesized by condensing aromatic amines with pyridoxal-5’-phosphate and characterized by using FT-IR, 1H NMR, and 13C NMR spectroscopic techniques. The resulting Schiff bases were utilized as bidentate ligands, coordinating via imine nitrogen and phenolate oxygen atoms, to stabilize palladium ions. Aryl substituents on imine nitrogen allowed for fine tuning of the stereoelectronic properties of the Schiff bases. The catalytic activity of the selected palladium complexes was investigated in the Suzuki cross-coupling reaction of a series of aryl halides with boronic acids in H2O/EtOH (1:1). Out of four complexes investigated in the cross-coupling reactions, Pd(L8)2, bearing a methoxy substituent on aryl imine, showed the highest activity at low catalyst loading. The scope of the reaction was also investigated with 26 samples.
- Neshat, Abdollah,Gholinejad, Mohammad,?zcan, Hafize,Khosravi, Faezeh,Mobarakeh, Ali Mousavizadeh,Zaim, ?mer
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- Magnetic nanoparticles supported N-heterocyclic palladium complex: Synthesis and catalytic evaluations in Suzuki cross-coupling reaction
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Because of the robustness and magnetic properties, the magnetic materials are promising and alternative candidate for the fabrication of noble metal in chemical catalysis from the viewpoint of green chemistry. Accordingly, an eco-friendly magnetic palladium catalyst loaded on N-Methylimidazole functionalized Fe3O4@SiO2 nanoparticles (Fe3O4@SiO2-NMIM-Pd) has been designed and prepared in the present work. The resultant composite exhibited excellent catalytic activity towards the Suzuki cross-coupling reaction for the synthesis of the corresponding biaryls in good to excellent yields (up to 96%) under aerobic conditions. In particular, this catalyst could be easily recovered through magnetic separation in a few cycles. The as-prepared palladium complex showed advantages including high thermal stability, low toxicity, moisture and oxygen insensitivities in Suzuki reactions. More importantly, this study presents a catalysis system, which will provide the magnetic materials access to the potential applications in a wide range of green organic catalysis.
- Dong, Yahao,Xue, Fengjun,Wei, Yuping
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- Pillar[5]arene-Based 3D Hybrid Supramolecular Polymer for Green Catalysis in Water
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Pillar[n]arene-based supramolecular polymers have attracted great interest because of their tunable morphologies and external stimuli responsiveness. However, most of the investigations of supramolecular polymers previously reported were focused on their formation and transformation, and investigations on their applications are rare. Herein, we designed and prepared hybrid polymeric materials by incorporating Pd nanoparticles into a supramolecular polymer, constructed from a pillar[5]arene dimer and a three-arm guest. The obtained hybrid polymer was fully characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron spectroscopy, scanning electron microscopy-energy-dispersive X-ray mapping, and X-ray diffraction technologies. Importantly, the hybrid supramolecular polymeric materials exhibited desirable catalytic activity for reductions of toxic nitroaromatics and C-C bond-forming Suzuki-Miyaura reaction in aqueous solution.
- Cai, Yan,Yan, Xin,Wang, Siyuan,Zhu, Zhiwen,Cen, Moupan,Ou, Changjin,Zhao, Qin,Yan, Qian,Wang, Jin,Yao, Yong
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p. 2883 - 2887
(2021/03/01)
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- Pd-NHCs Enabled Suzuki-Miyaura Cross-Coupling of Arylhydrazines via C–N Bond Cleavage
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We describe a highly efficient protocol for cross-coupling of phenylhydrazines with arylboronic acids by Pd-NHCs under aerobic reaction condition. A series of well-defined Pd-NHCs complexes were evaluated and the relationship between the structure and the catalytic properties was investigated. It was disclosed that the Pd-PEPPSI-IPr proved to be the robust precatalyst, providing access to a range of (hetero)biaryls in good to excellent yields.
- Zeng, Xiao-Xiao,Li, Dong-Hui,Zhou, Zhen,Xu, Chang,Liu, Feng-Shou
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supporting information
(2021/03/01)
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- Modular and Selective Arylation of Aryl Germanes (C?GeEt3) over C?Bpin, C?SiR3 and Halogens Enabled by Light-Activated Gold Catalysis
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Selective C (Formula presented.) –C (Formula presented.) couplings are powerful strategies for the rapid and programmable construction of bi- or multiaryls. To this end, the next frontier of synthetic modularity will likely arise from harnessing the coupling space that is orthogonal to the powerful Pd-catalyzed coupling regime. This report details the realization of this concept and presents the fully selective arylation of aryl germanes (which are inert under Pd0/PdII catalysis) in the presence of the valuable functionalities C?BPin, C?SiMe3, C?I, C?Br, C?Cl, which in turn offer versatile opportunities for diversification. The protocol makes use of visible light activation combined with gold catalysis, which facilitates the selective coupling of C?Ge with aryl diazonium salts. Contrary to previous light-/gold-catalyzed couplings of Ar–N2+, which were specialized in Ar–N2+ scope, we present conditions to efficiently couple electron-rich, electron-poor, heterocyclic and sterically hindered aryl diazonium salts. Our computational data suggest that while electron-poor Ar–N2+ salts are readily activated by gold under blue-light irradiation, there is a competing dissociative deactivation pathway for excited electron-rich Ar–N2+, which requires an alternative photo-redox approach to enable productive couplings.
- Dahiya, Amit,Fricke, Christoph,Funes-Ardoiz, Ignacio,Gevondian, Avetik G.,Schoenebeck, Franziska,Sherborne, Grant J.
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p. 15543 - 15548
(2020/06/22)
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- Method for synthesizing biphenyl compound by taking phenol as raw material
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The invention discloses a method for synthesizing a biphenyl compound by using phenol as a raw material in the technical field of organic chemical synthesis, which comprises the following steps: carrying out a mixed reaction process on phenol or substituted phenol, alkali and 50-90% ethanol aqueous solution, slowly introducing sulfonyl fluoride gas, and carrying out magnetic stirring reaction at normal temperature for 4-12 hours, adding arylboronic acid, alkali and a palladium catalyst into a round-bottom flask, continuing to react for 6-12 hours at normal temperature, after the reaction is finished, adding a saturated edible salt solution into the round-bottom flask, carrying out a water quenching reaction process to obtain a reaction mixture, extracting a reaction product from the reaction mixture by using ethyl acetate, combining organic phases, concentrating filtrate, and separating the concentrated filtrate by using column chromatography to obtain analytically pure biphenyl or terphenyl compounds. By using the method, on one hand, the production cost of the biphenyl compound is reduced, and on the other hand, the method also has a wide application prospect in the aspects of synthesis of natural products, medicines, pesticides, herbicides, polymer conduction materials, liquid crystal materials and the like.
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Paragraph 0065-0067
(2020/07/15)
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- NaH-mediated direct C-H arylation in the presence of 1,10-phenanthroline
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Transition-metal-free coupling of haloarenes with unactivated arenes has been developed in the presence of NaH and 1,10-phenanthroline. Various haloarenes bearing methyl, methoxy, halogen (fluoride, chloride, and bromide), cyano, trifluoromethyl, ester, and amide groups can be cross-coupled with unactivated arenes, or heteroarenes in this reaction.
- Nozawa-Kumada, Kanako,Iwakawa, Yuki,Onuma, So,Shigeno, Masanori,Kondo, Yoshinori
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supporting information
p. 7773 - 7776
(2020/07/27)
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- Catalytic and stoichiometric reactions of Arylpalladium(II) complexes bearing a trans-chelating dinitrogen ligand with arylboronic acids
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Pd(II) complexes with 1,2-bis(2′-pyridylethylnyl)benzene (bpeb) ligand, PdCl2(bpep) and Pd(OAc)2(bpep), catalyze cross-coupling of arylboronic acids and aryl iodide, in spite of the trans-chelation of the ligand. Arylpalladium iodo and trifluoroacetate complexes with bpep ligand, Pd(C6H4X-4)(I)(bpep) (3a-3h, X = OMe, Me, H, COMe, CHO, COOEt, NO2, F), Pd(C6H3F2-2,4)(I)(bpep) (3i), Pd(C6H4X-4)(OCOCF3)(bpep) (4a-4e, X = OMe, Me, H, COMe, CHO) and Pd(C6F5)(OCOCF3)(bpep) (4j), were obtained by ligand exchange of the Pd complexes having tmeda ligand (tmeda = N,N,N′,N′-tetramethylethylenedi-amine). X-ray crystallographic results of arylpalladium(II) trifluoroacetate complex, Pd(C6H4OMe-4)(OCOCF3)(bpeb) (4a), and bis(trifluoroacetate)palladium(II) complex, Pd(OCOCF3)2(bpeb) (5) revealed the structures with two pyridyl groups of bpeb coordinated to Pd(II) in a trans-chelating bidentate mode. 2-Pyridyl hydrogens and an acetate oxygen of 5 are at close positions to each other (2.52 and 2.66 ?). The reaction of (4-MeC6H4)B(OH)2 (7b) with Pd(C6H4OMe-4)(OCOCF3)(bpeb) (4a) in the presence of Ag2O yields Pd(C6H4Me-4)(OCOCF3)(bpeb) (4b) via exchange of the aryl group between the palladium complex and arylboronic acid. The reaction of (4-CHOC6H4)B(OH)2 (7e) yields not only Pd(C6H4CHO-4)(OCOCF3)(bpeb) (4e) but also biaryls, 4-MeOC6H4-C6H4Y-4 (Y = OMe (8a), CHO (8e)). Hammett plots of the reaction exchange suggest higher reactivity of the Pd complex with more electron-donating aryl ligand.
- Suzaki, Yuji,Saito, Takashi,Osakada, Kohtaro
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supporting information
(2020/01/30)
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- Palladium Supported on Silk Fibroin for Suzuki–Miyaura Cross-Coupling Reactions
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Silk fibroin supported Pd (Pd/SF) has been prepared and used as catalyst in Suzuki–Miyaura cross-coupling reactions in water/ethanol (4:1 v/v) mixture. The reactions proceed rapidly with aryl iodides and boronic acids with different electronic properties using low metal loading (0.38 mol-%). Pd/SF exhibits better recyclability compared to other biopolymer-supported Pd catalysts, up to nineteen cycles without loss of activity.
- Albano, Gianluigi,Farinola, Gianluca M.,Lo Presti, Marco,Milella, Antonella,Omenetto, Fiorenzo G.,Rizzo, Giorgio
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supporting information
p. 6992 - 6996
(2020/11/30)
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- Preparation and characterization of Cu supported on 2-(1H-benzo[d]imidazol-2-yl)aniline-functionalized Fe3O4 nanoparticles as a novel magnetic catalyst for Ullmann and Suzuki cross-coupling reactions
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Copper supported on 2-(1H-benzo[d]imidazol-2-yl)aniline (BIA)-functionalized Fe3O4 nanoparticles (Cu-BIA-Si-Fe3O4) as a novel magnetic catalyst was designed and used for the synthesis of new products via Ullmann and Suzuki cross-coupling reactions. The Ullmann reaction was performed by mixing arylboronic acid with aniline derivatives in dimethylsulfoxide solvent. Also, diaryls were synthesized via Suzuki C–C reactions between aryl halides and phenylboronic acid in the same solvent. The prepared materials and catalyst were characterized with various analytical techniques. The Cu-BIA-Si-Fe3O4 catalyst demonstrated catalytic efficiency with good to excellent yields for both types of reactions in comparison with commercial palladium catalysts. Also, the catalyst could be recovered by a simple filtration and retained its activity even after several cycles.
- Danqing, Liang,Ming, Jin,Li, Li,Mohammadnia, Majid
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- Integrating Reactors and Catalysts through Three-Dimensional Printing: Efficiency and Reusability of an Impregnated Palladium on Silica Monolith in Sonogashira and Suzuki Reactions
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For this work, an integrated system composed of a polypropylene reactor and a palladium on silica monolithic catalyst was designed and manufactured by 3D-printing. These devices are able to perform solution phase chemistry in a robotic orbital shaker. The capped reactor was obtained in its entirety by 3D-printing, using polypropylene and fused deposition modeling. The monolithic catalyst was also obtained by 3D-printing -robocasting- of a silica support, sintering and subsequent palladium deposition through the wet impregnation method. The catalytic efficiency in Sonogashira or Suzuki reactions as well as the recyclability of the entire system – catalyst+reactor – were studied. The strong electrostatic adsorption (SEA) of the palladium on sintered silica and the reduced mechanical stress produced by the convenient adjustment of the catalyst into the polypropylene reactor makes the catalytic system reusable without significant loss of catalytic activity.
- Díaz-Marta, Antonio S.,Ya?ez, Susana,Lasorsa, Eliana,Pacheco, Patricia,Tubío, Carmen R.,Rivas, José,Pi?eiro, Yolanda,Gómez, Manuel A. Gonzalez,Amorín, Manuel,Guitián, Francisco,Coelho, Alberto
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p. 1762 - 1771
(2020/02/15)
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- Suzuki-Miyaura Cross-Coupling of Sulfoxides
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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
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p. 8168 - 8176
(2020/09/18)
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- Synthesis and characterization of Pd based on [2,2'- bipyridin]-4-amine functionalized nano cellulose as a novel and recyclable nano catalyst for Suzuki reaction
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In this work, it was designed and prepared an efficient nanocatalyst Pd based on [2,2'- bipyridin]-4-amine functionalized nano cellulose (Pd?BPA?CNC) and then characterized by FT-IR, XRD, ICP-AES, EDX, SEM, TEM and TGA techniques. The catalytic activity of the nanocatalyst was investigated through one-pot synthesis of biaryl derivatives from the reaction of aryl halides with arylboronic acids in DMSO solvent conditions. This Simple and mild procedure displayed excellent recyclability and provided cleaner conversion in a short reaction time. All of these advantages make the protocol feasible and economical attractive for researchers.
- Mohammadnia, Majid,Sun, Yuqi
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- Direct suzuki-miyaura coupling with naphthalene-1,8-diaminato (dan)-substituted organoborons
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The actually direct Suzuki-Miyaura coupling with "protected" R-B(dan) (dan = naphthalene-1,8-diaminato) was demonstrated to smoothly occur without in situ deprotection of the B(dan) moiety. The use of t-BuOK (Ba(OH)2 in some cases) as a base under anhydrous conditions is the key to the successful cross-coupling, where R-B(dan) is readily converted into a transmetalation-active borate-form, regardless of the well-accepted diminished boron-Lewis acidity.
- Yoshida, Hiroto,Seki, Michinari,Kamio, Shintaro,Tanaka, Hideya,Izumi, Yuki,Li, Jialun,Osaka, Itaru,Abe, Manabu,Andoh, Hiroki,Yajima, Tomoki,Tani, Tomohiro,Tsuchimoto, Teruhisa
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p. 346 - 351
(2019/12/24)
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- Aqueous Suzuki-Miyaura coupling with ultralow palladium loading and simple product separation
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The diphosphine ligand N, N -bis(diphenylphosphanylmethyl)-aniline (bdppma) and PdCl 2afforded a Suzuki-Miyaura catalyst [(bdppm-)PdCl 2] that was highly efficient at an ultralow catalyst loading (0.001 mol%) in 20:1 H 2O-EtOH. This low catalyst loading in an aqueous solvent system permitted simple product separation by direct filtration without the need for chromatography. The ligand bdppma imparted surprisingly better reactivity than that achieved with other bidentate diphosphine ligands, but the catalytic system had a slightly narrower substrate scope than some similar Pd catalysts reported previously.
- Yang, Wei,Xu, Wen-Di,Ning, Jin-Jiao,Ren, Zhi-Gang,Young, David James
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supporting information
p. 1303 - 1307
(2020/08/21)
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- Cost-effective bio-derived mesoporous carbon nanoparticles-supported palladium catalyst for nitroarene reduction and Suzuki–Miyaura coupling by microwave approach
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A new heterogeneous catalyst was synthesized by immobilizing Pd on areca nut kernel-derived carbon nanospheres (CNSs). The CNSs, without any further activation processes, accommodated 3% of Pd on their surface. The new Pd/CNS material was used for the reduction of nitroarenes and Suzuki–Miyaura coupling of bromoarenes with aryl boronic acids. The reactions were conducted under microwave irradiation at 160 °C using 12 mol% of Pd/CNS (0.36% actual Pd content). The reduction of nitroarenes into their respective amino compounds was achieved in 10–20 min (conversion up to 100%); by contrast, the Suzuki–Miyaura reactions yielded up to 98% at 150 °C with 10 mol% of Pd/CNS catalyst. The products were identified using gas chromatography and nuclear magnetic resonance spectroscopy. The catalyst was isolated from reaction mixture and reused without any significant loss in the activity. Thus, the present work introduces one-pot-derived porous CNSs as efficient catalytic support to Pd, establishing an alternative to existing Pd/C in terms of cost and efficiency.
- Supriya,Ananthnag, Guddekoppa S.,Shetti, Vijayendra S.,Nagaraja,Hegde, Gurumurthy
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- Method for synthesizing biphenyl compound by taking suaeda salsa extract liquor as solvent
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The invention discloses a method for synthesizing a biphenyl compound by using suaeda salsa extract as a solvent in the technical field of organic chemical synthesis, which comprises the following steps: roasting suaeda salsa in a muffle furnace to obtain ash, dissolving the ash in distilled water, refluxing, cooling the solution, and filtering to obtain a faint yellow solution which is the suaedasalsa extract liquor; sequentially adding 1mmol of aryl halide, 1.1mmol of arylboronic acid, 0.001mmol to 0.01mmol of a catalyst and 4ml of the suaeda salsa extract liquor into a round-bottom flask,stirring at 100 DEG C to react for 2 hours, cooling the reactant to room temperature, filtering, mixing the obtained filter residue with a palladium catalyst to obtain a mixture; and dissolving the mixture in ethyl acetate, filtering to remove the palladium catalyst, and drying the filtrate by distillation to obtain the biphenyl compound. According to the scheme, a phosphine ligand, alkali and anadditive do not need to be added, a Suzuki reaction system with biomass extract as a reaction medium is adopted, and a green, simple, convenient and efficient method is provided for synthesizing biphenyl compounds.
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Paragraph 0055-0056
(2020/06/30)
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- Bulky α-diimine palladium complexes supported graphene oxide as heterogeneous catalysts for Suzuki-Miyaura reaction
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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
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- Decarbonylative Suzuki-Miyaura Cross-Coupling of Aroyl Chlorides
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Herein, we report a catalyst system for Pd-catalyzed decarbonylative Suzuki-Miyaura cross-coupling of aroyl chlorides with boronic acids to furnish biaryls. This strategy is suitable for a broad range of common aroyl chlorides and boronic acids. The synthetic utility is highlighted in the direct late-stage functionalization of pharmaceuticals and natural products capitalizing on the presence of carboxylic acid moiety. Extensive mechanistic and DFT studies provide key insight into the reaction mechanism and high decarbonylative cross-coupling selectivity.
- Zhou, Tongliang,Xie, Pei-Pei,Ji, Chong-Lei,Hong, Xin,Szostak, Michal
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supporting information
p. 6434 - 6440
(2020/09/02)
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- Novel and efficient bridged bis(N-heterocyclic carbene)palladium(II) catalysts for selective carbonylative Suzuki–Miyaura coupling reactions to biaryl ketones and biaryl diketones
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Bridged N,N′-substituted bisbenzimidazolium bromide salts (L1, L2, and L3) were synthesized and fully characterized. Reactions of palladium acetate with L1, L2, and L3 afforded corresponding new bridged bis(N-heterocyclic carbene)palladium(II) complexes (C1, C2, and C3) in high yields. The X-ray structure of complex C1 showed that the Pd(II) ion is bonded to the two carbon atoms of the bis(N-heterocyclic carbene) and two bromido ligands are in the cis position, resulting in a distorted square planar geometry. The three Pd(NHC)2Br2 complexes C1, C2, and C3 were evaluated in carbonylative Suzuki–Miyaura coupling reactions of aryl boronic acids with aryl halides and displayed high catalytic activity with low catalyst loading. The coupling reactions of aryl bromides were selective towards the carbonylation product at higher carbon monoxide pressure.
- El Ali, Bassam,Fettouhi, Mohammed,Mansour, Waseem
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- Cobalt-Catalyzed Cross-Coupling Reactions of Aryl Triflates and Lithium Arylborates
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A catalyst system comprising CoCl2/IAd·HBF4 enables the Suzuki-Miyaura cross-coupling reaction of a broad range of aryl triflates and arylboronic esters that are activated by n-butyllithium.
- Duong, Hung A.,Yeow, Zong-Han,Tiong, Yong-Lun,Mohamad Kamal, Nur Haidah Binte,Wu, Wenqin
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p. 12686 - 12691
(2019/10/11)
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- Decarboxylative Suzuki-Miyaura coupling of (hetero)aromatic carboxylic acids using iodine as the terminal oxidant
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A novel methodology for the decarboxylative Suzuki-Miyaura-type coupling has been established. This process uses iodine or a bromine source as both the decarboxylation mediator and the terminal oxidant, thus avoiding the need for stoichiometric amounts of transition metal salts previously required. Our new protocol allows for the construction of valuable biaryl architectures through the coupling of (hetero)aromatic carboxylic acids with arylboronic acids. The scope of this decarboxylative Suzuki reaction has been greatly diversified, allowing for previously inaccessible non-ortho-substituted aromatic acids to undergo this transformation. The procedure also benefits from low catalyst loadings and the absence of stoichiometric transition metal additives.
- Quibell, Jacob M.,Duan, Guojian,Perry, Gregory J.P.,Larrosa, Igor
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p. 6445 - 6448
(2019/06/07)
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- Ni-Catalyzed Reductive Cyanation of Aryl Halides and Phenol Derivatives via Transnitrilation
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Herein, we report a Ni-catalyzed reductive coupling for the synthesis of benzonitriles from aryl (pseudo)halides and an electrophilic cyanating reagent, 2-methyl-2-phenyl malononitrile (MPMN). MPMN is a bench-stable, carbon-bound electrophilic CN reagent that does not release cyanide under the reaction conditions. A variety of medicinally relevant benzonitriles can be made in good yields. Addition of NaBr to the reaction mixture allows for the use of more challenging aryl electrophiles such as aryl chlorides, tosylates, and triflates. Mechanistic investigations suggest that NaBr plays a role in facilitating oxidative addition with these substrates.
- Mills, L. Reginald,Graham, Joshua M.,Patel, Purvish,Rousseaux, Sophie A. L.
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supporting information
p. 19257 - 19262
(2019/12/02)
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- Suzuki–Miyaura Coupling of (Hetero)Aryl Sulfones: Complementary Reactivity Enables Iterative Polyaryl Synthesis
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Ideal organic syntheses involve the rapid construction of C?C bonds, with minimal use of functional group interconversions. The Suzuki–Miyaura cross-coupling (SMC) is a powerful way to form biaryl linkages, but the relatively similar reactivity of electrophilic partners makes iterative syntheses involving more than two sequential coupling events difficult to achieve without additional manipulations. Here we introduce (hetero)aryl sulfones as electrophilic coupling partners for the SMC reaction, which display an intermediate reactivity between those of typical aryl (pseudo)halides and nitroarenes. The new complementary reactivity allows for rapid sequential cross-coupling of arenes bearing chloride, sulfone and nitro leaving groups, affording non-symmetric ter- and quateraryls in only 2 or 3 steps, respectively. The SMC reactivity of (hetero)aryl sulfones is demonstrated in over 30 examples. Mechanistic experiments and DFT calculations are consistent with oxidative addition into the sulfone C?S bond as the turnover-limiting step. The further development of electrophilic cross-coupling partners with complementary reactivity may open new possibilities for divergent iterative synthesis starting from small pools of polyfunctionalized arenes.
- Chatelain, Paul,Sau, Abhijit,Rowley, Christopher N.,Moran, Joseph
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supporting information
p. 14959 - 14963
(2019/11/05)
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- Preparation of Polyfunctional Arylzinc Organometallics in Toluene by Halogen/Zinc Exchange Reactions
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A wide range of polyfunctional diaryl- and diheteroarylzinc species were prepared in toluene within 10 min to 5 h through an I/Zn or Br/Zn exchange reaction using bimetallic reagents of the general formula R′2Zn?2 LiOR (R′=sBu, tBu, pTol). Highly sensitive functional groups, such as a triazine, a ketone, an aldehyde, or a nitro group, were tolerated in these exchange reactions, enabling the synthesis of a plethora of functionalized (hetero)arenes after quenching with various electrophiles. Insight into the constitution and reactivity of these bimetallic mixtures revealed the formation of highly active lithium diorganodialkoxyzincates of type [R′2Zn(OR)2Li2].
- Balkenhohl, Moritz,Ziegler, Dorothée S.,Desaintjean, Alexandre,Bole, Leonie J.,Kennedy, Alan R.,Hevia, Eva,Knochel, Paul
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supporting information
p. 12898 - 12902
(2019/07/31)
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- Unified Protocol for Fe-Based Catalyzed Biaryl Cross-Couplings between Various Aryl Electrophiles and Aryl Grignard Reagents
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The combination of commonly used FeCl3/SIPr with Ti(OEt)4/PhOM enabled a highly general iron-based catalyst system, which could efficiently catalyze the biaryl coupling reaction between various electrophiles (I, Br, Cl, OTs, OCONMe2, OSO2NMe2) and common or functionalized aryl Grignard reagents with high functional group tolerance. Selective couplings of aryl iodides and bromides over the corresponding oxygen-based electrophiles have been achieved, and thus a terphenyl acid intermediate for anidulafungin was conveniently synthesized via an orthogonal coupling strategy.
- Wang, Lei,Wei, Yi-Ming,Zhao, Yan,Duan, Xin-Fang
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p. 5176 - 5186
(2019/05/10)
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- Ligand-free palladium catalyzed Ullmann biaryl synthesis: 'Household' reagents and mild reaction conditions
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A palladium catalysed Ullmann biaryl synthesis has been developed using hydrazine hydrate as the reducing reagent at room temperature. The combination of Pd(OAc)2 and hydrazine hydrate works smoothly for the coupling of both electron-rich and electron-deficient aryl iodides, as well as hetero-aryl iodides, leading to a wide range of biaryls in good to excellent yields. The reaction requires only 1 mol% Pd(OAc)2 and the in situ generated palladium naoparticles are found to be active catalysts.
- Gong, Xinchi,Wu, Jie,Meng, Yunge,Zhang, Yulan,Ye, Long-Wu,Zhu, Chunyin
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supporting information
p. 995 - 999
(2019/03/12)
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- Practical Ni-Catalyzed Cross-Coupling of Unsaturated Zinc Pivalates with Unsaturated Nonaflates and Triflates
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A practical nickel-catalyzed cross-coupling of (hetero)aryl or alkynylzinc pivalates with various unsaturated nonaflates or triflates is described. Organozinc pivalates allow these cross-couplings to take place with high yields and a low catalyst loading (0.5 mol %). Couplings with (E)- and (Z)-alkenyl triflates proceed with retention of configuration.
- Hofmayer, Maximilian S.,Lutter, Ferdinand H.,Grokenberger, Lucie,Hammann, Jeffrey M.,Knochel, Paul
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- An N-heterocyclic carbene-functionalised covalent organic framework with atomically dispersed palladium for coupling reactions under mild conditions
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Covalent organic frameworks (COFs) are a new class of crystalline porous materials that could function as excellent scaffolds for heterogeneous catalysts. Herein, we report a functionalised COF (COF-NHC) using N-heterocyclic carbene (NHC) as a monomer building block via a facile ionothermal strategy. The simple and easily prepared imine-linked COF-NHC possessed two coordination sites (NHC and amine), which could fix the active component (Pd) tightly in COF, leading to atomically dispersed Pd in a heterogeneous catalyst. The as-prepared Pd@COF-NHC showed high stability in the Suzuki-Miyaura coupling reaction of arylboronic acids and aryl halides in aqueous media at room temperature, and could be easily recycled and reused multiple times without the loss of catalytic activity. Moreover, C-C coupling reactions could be accomplished using triarylbismuth reagents in ethanol aqueous solutions with high yields.
- Yang, Junjuan,Wu, Yuanyuan,Wu, Xiaowei,Liu, Wenjing,Wang, Yaofang,Wang, Junwen
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supporting information
p. 5267 - 5273
(2019/10/11)
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- Palladium Palladium Nanoparticles Nanoparticles Supported Supported on β-cyclodextrin on β-Cyclodextrin Functionalised Functionalized Poly(amido Poly(amidoamine)s amine)s and their and Application Their Application in Suzuki-Miyaura in Suzuki-Miyaura Cross-Coupling Cross-Coupling Reactions Reactions
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Herein, the synthesis, characterization and catalytic application of an organic-inorganic, palladium (Pd)-containing hybrid material, poly(amidoamine)-cyclodextrin (Pd@PAAs-CD), is reported as an efficient catalyst for Suzuki-Miyaura coupling reactions. The structure of Pd@PAAs-CD was confirmed by Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), inductively-coupled plasma atomic emission spectroscopy (ICP-AES), and 1H nuclear magnetic resonance (NMR) spectroscopy. Furthermore, an efficient protocol has been developed using Pd@PAAs-CD as the catalyst in a Suzuki-Miyaura cross-coupling reaction in an aqueous medium in high yields. By using cyclodextrin (CD) as the mediator grafted onto PAAs, the Pd nanoparticles (NPs) were dispersed and enhanced the catalytic reaction by promoting host-guest interactions with the CD. In addition, the reusability of the Pd@PAAs-CD hybrid material is demonstrated for use in multiple sequential cross-coupling reactions.
- Zhang, Wei,Yao, Zi-Jian,Deng, Wei
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p. 1667 - 1677
(2019/10/01)
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- Palladium/phosphorus-functionalized porous organic polymer with tunable surface wettability for water-mediated Suzuki-Miyaura coupling reaction
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A series of phosphorus-functionalized porous organic polymers supported palladium catalysts with tunable surface wettability were successfully prepared using an easy copolymerization and successive immobilization method. The obtained polymers were carefully characterized by many physicochemical methods. Characterization results suggested that the prepared materials featured hierarchically porous structures, high pore volumes, tunable surface wettability and strong electron-donating ability towards palladium species. We demonstrated the use of these solid catalysts for water-mediated Suzuki-Miyaura coupling reactions. It was found that the surface wettability of the prepared catalysts has an important influence on their catalytic activities. The optimal catalyst, which has excellent amphipathicity and relatively high phosphorus concentration, displayed superior catalytic activity compared to the other catalysts. Under ambient conditions, a variety of aryl chlorides can be efficiently transformed to biaryls in high yields. Moreover, the catalyst could be easily recovered and reused at least six times.
- Lei, Yizhu,Chen, Zaifei,Li, Guangxing
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p. 36600 - 36607
(2019/11/25)
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- Atom-efficient Pd-catalyzed cross-couplings of chloroarenes with triarylbismuth reagents
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Various Pd-catalyzed protocols have been developed for the atom-efficient cross-coupling of chloroarenes with triarylbismuth reagents. Using the developed protocols, an efficient synthesis of unsymmetrical biaryls in good to excellent yields was achieved by employing electron-deficient chloroarenes and a range of triarylbismuth reagents.
- Rao, Maddali L.N.,Meka, Suresh
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supporting information
(2019/07/30)
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- Nickel-catalyzed cyanation of aryl halides and triflates using acetonitrile: Via C-CN bond cleavage assisted by 1,4-bis(trimethylsilyl)-2,3,5,6-tetramethyl-1,4-dihydropyrazine
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We developed a non-toxic cyanation reaction of various aryl halides and triflates in acetonitrile using a catalyst system of [Ni(MeCN)6](BF4)2, 1,10-phenanthroline, and 1,4-bis(trimethylsilyl)-2,3,5,6-tetramethyl-1,4-dihydropyrazine (Si-Me4-DHP). Si-Me4-DHP was found to function as a reductant for generating nickel(0) species and a silylation reagent to achieve the catalytic cyanation via C-CN bond cleavage.
- Ueda, Yohei,Tsujimoto, Nagataka,Yurino, Taiga,Tsurugi, Hayato,Mashima, Kazushi
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p. 994 - 999
(2019/02/03)
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- PdII Immobilized on Ferromagnetic Multi-Walled Carbon Nanotubes Functionalized by Aminated 2-Chloroethylphosphonic Acid with S -Methylisothiourea (FMMWCNTs@CPA@SMTU@PdII NPs) Applied as a Highly Efficient and Recyclable Nanostructured Catalyst for Suzuki-Miyaura and Mizoroki-Heck Cross-Coupling Reactions in Solvent-Free Conditions
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The new ferromagnetic nanostructured FMMWCNTs@CPA@SMTU@PdII NPs (IV) as an eco-friendly heterogeneous nanocatalyst with a particle size of ~20-30 nm reported earlier by our group has been found to be very effective for Suzuki-Miyaura and Mizoroki-Heck cross-coupling reactions at ambient temperature. The procedure has been applied for a wide range of aryl halides, arylboronic acids, and alkenes. The magnetic separation by an external magnetic field, mild reaction conditions, and catalyst reusability up to four times without significant decrease in catalytic activity (reduced catalytic activity from 11 to 18 % in the fifth, sixth, and seventh cycles) made the present method sustainable and economically viable for C-C cross-coupling reactions.
- Ghasemzadeh, Maryam Sadat,Akhlaghinia, Batool
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p. 674 - 692
(2019/07/12)
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- A Molecular/Heterogeneous Nickel Catalyst for Suzuki-Miyaura Coupling
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A molecular/heterogeneous catalyst motif based on an earth abundant nickel catalyst and SiO2 support has been designed and synthesized. Characterization and catalytic testing indicate that the molecular nickel catalyst [(2,2′:6′,2′′-terpyridine-4′-benzoic acid)Ni(II)]Cl2 attached to a high surface area SiO2 support is the active cross-coupling catalyst and increased product yields are a result of increased molecular stability of the catalyst while attached to the SiO2 support. This molecular/heterogeneous motif is easily separated from reaction mixtures and can be recycled for multiple catalytic reactions. The catalyst is active for Suzuki-Miyaura catalysis at catalyst loadings as low as 0.1 mol %, and turnover numbers nearing 2000 have been achieved.
- Key, Ryan J.,Tengco, John Meynard M.,Smith, Mark D.,Vannucci, Aaron K.
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p. 2007 - 2014
(2019/05/16)
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- Palladium-catalyzed water-phase Suzuki cross-coupling reaction without additional ligand
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The invention discloses a palladium-catalyzed water-phase Suzuki cross-coupling reaction without an additional ligand, which is characterized in that palladium is used as a catalytic species, water isused as a solvent, and quaternary ammonium base and an emulsifier are utilized to carry out high-efficiency palladium-catalyzed carbon-carbon bond cross-coupling reaction to synthesize a bi-aromatichydrocarbon compound. The reaction system is green, reaction conditions are mild, catalysis can be completed for 3 minutes at a high temperature, and possibility is provided for catalysis on a fluidized bed. The catalyst is free of the additional ligand; wherein compared with traditional inorganic base, the quaternary ammonium base plays a role in stabilizing catalytic species palladium to a certain extent, the use amount of palladium is reduced, the catalyst can be directly reused in the cyclic utilization process, and the quaternary ammonium base can be repeatedly used for 8 times or above on the premise that the activity is not remarkably reduced. A catalytic product can be directly crystallized and separated out in a system, a pure product is obtained through a filtering and washing method, the step of column chromatography is omitted, and operation is easy, convenient and safe. In addition, the reaction system is good in universality to reaction substrates, and has great practicalapplication value.
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Paragraph 0018; 0041-0042
(2019/12/02)
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- Readily Available Immobilized Pd Catalysts for Suzuki-Miyaura Coupling under Continuous-flow Conditions
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Highly efficient immobilized catalysts for continuous-flow cross-coupling reactions that show better productivity than those for the corresponding batch reactions are increasingly in demand. For practical use, such catalysts should have highly catalytic activity and high leaching resistance. To find catalysts suitable for continuous-flow conditions, we have developed a consistent method for evaluating the catalytic performance of commercially available immobilized Pd catalysts. Monitoring of the change in turnover frequency over time under excess substrate loading conditions revealed the limitation of these catalysts. On the basis of the evaluation results, we have successfully developed a new immobilized Pd catalyst that exhibited highly efficient and robust catalytic performance.
- Ichitsuka, Tomohiro,Suzuki, Naoto,Sairenji, Masaki,Koumura, Nagatoshi,Onozawa, Shun-ya,Sato, Kazuhiko,Kobayashi, Shū
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p. 2427 - 2431
(2019/04/27)
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- Rapid Suzuki-Miyaura cross-coupling reaction catalyzed by zirconium carboxyphosphonate supported mixed valent Pd(0)/Pd(II) catalyst
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Mixed valent Pd(0)/Pd(II) nano-sized aggregates supported onto a chemically robust layered zirconium carboxyphosphonate framework is prepared and its catalytic activity in Suzuki-Miyaura cross coupling reaction is explored. The exceptionally high catalytic efficacy of the heterogeneous catalyst in Suzuki-Miyaura cross coupling reaction is signified by remarkably short reaction time 2?minutes and high turnover frequency of 1.3 x 104?hr?1. The catalyst can be recycled several times without significant loss of catalytic efficacy, while spectroscopic, structural and microscopic investigations suggest the integrity of the catalyst even after fifth catalytic cycle. The unique ability of the zirconium carboxyphosphonate framework to interact strongly with palladium in dual Pd(0)/Pd(II) oxidation states has been attributed to this remarkable augmentation of catalytic efficacy.
- Bhattacharyya, Bagmita,Biswas, Jyoti Prasad,Mishra, Shashank,Gogoi, Nayanmoni
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- Base-free nickel-catalysed decarbonylative Suzuki–Miyaura coupling of acid fluorides
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The Suzuki–Miyaura cross-coupling of organoboron nucleophiles with aryl halide electrophiles is one of the most widely used carbon–carbon bond-forming reactions in organic and medicinal chemistry1,2. A key challenge associated with these transformations is that they generally require the addition of an exogenous base, the role of which is to enable transmetallation between the organoboron nucleophile and the metal catalyst3. This requirement limits the substrate scope of the reaction because the added base promotes competitive decomposition of many organoboron substrates3–5. As such, considerable research has focused on strategies for mitigating base-mediated side reactions6–12. Previous efforts have primarily focused either on designing strategically masked organoboron reagents (to slow base-mediated decomposition)6–8 or on developing highly active palladium precatalysts (to accelerate cross-coupling relative to base-mediated decomposition pathways)10–12. An attractive alternative approach involves identifying combinations of catalyst and electrophile that enable Suzuki–Miyaura-type reactions to proceed without an exogenous base12–14. Here we use this approach to develop a nickel-catalysed coupling of aryl boronic acids with acid fluorides15–17, which are formed in situ from readily available carboxylic acids18–22. This combination of catalyst and electrophile enables a mechanistic manifold in which a ‘transmetallation-active’ aryl nickel fluoride intermediate is generated directly in the catalytic cycle13,16. As such, this transformation does not require an exogenous base and is applicable to a wide range of base-sensitive boronic acids and biologically active carboxylic acids.
- Malapit, Christian A.,Bour, James R.,Brigham, Conor E.,Sanford, Melanie S.
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p. 100 - 104
(2018/11/25)
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- Mechanochemical Activation of Zinc and Application to Negishi Cross-Coupling
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A form independent activation of zinc, concomitant generation of organozinc species and engagement in a Negishi cross-coupling reaction via mechanochemical methods is reported. The reported method exhibits a broad substrate scope for both C(sp3)–C(sp2) and C(sp2)–C(sp2) couplings and is tolerant to many important functional groups. The method may offer broad reaching opportunities for the in situ generation organometallic compounds from base metals and their concomitant engagement in synthetic reactions via mechanochemical methods.
- Cao, Qun,Howard, Joseph L.,Wheatley, Emilie,Browne, Duncan L.
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p. 11339 - 11343
(2018/08/28)
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