- Palladium-catalyzed benzoin-mediated redox process leading to biaryls from aryl halides
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An expedient synthetic procedure of biaryl derivatives was developed using a palladium-catalyzed, benzoin-mediated redox process from aryl halides. Various biaryls were synthesized in good yields in short time.
- Park, Bo Ram,Kim, Ko Hoon,Kim, Taek Hyeon,Kim, Jae Nyoung
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- The Oxidative Coupling of Methyl Benzoate
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The reaction of methyl benzoate (MBA) with pressurized (50 atm) artificial air (50 mol% O2-N2 mixture) at 150-200°C over a soluble palladium catalyst [PdLL2′] (L=phen, bipy, dppe; L′=OAc, TFA) afforded isomeric dimethyl bibenzoic acid esters (DMBBA). Different factors affect the reactivity and regioselectivity of the process. The reactivity is enhanced by trifluoromethanesulfonic acid, arguably by activating the C-H bond of the aromatic ring by its protonation. The increase of temperature not only increases the reaction rate (EA=5.5 kcal/mol) but also favors a formation of an ortho-coupled product. Ligands with strong trans influence (L=phen, bipy, or dppe) direct the oxidative coupling away from 2,X′-isomers (X=2, 3, or 4). Overall, electronic properties of a palladium catalyst are more important than steric restriction of the same catalyst for altering the activity and regioselectivity for MBA coupling.
- Iretskii,Sherman,White,Kenvin,Schiraldi
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- The coupling of aryl halides in the ionic liquid [bmim]PF6
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Several aryl halides have been coupled using the zero valent nickel catalyst [(PPh3)(n)Ni(0)], to give the biaryl in moderate to good yield, employing the ionic liquid [bmim]PF6. The ionic liquid and catalyst were recycled after extraction of the biaryl. (C) 2000 Elsevier Science Ltd.
- Howarth, Joshua,James, Paraic,Dai, Jifeng
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- New Role of CO2 as a Selective Agent in Palladium-Catalyzed Reductive Ullmann Coupling with Zinc in Water
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Carbon dioxide was found to promote the palladium-catalyzed zinc-mediated reductive Ullmann coupling of aryl halides. In the presence of carbon dioxide, Pd/C, and zinc, various aromatic halides including less reactive aromatic chlorides were coupled to give the corresponding homocoupling products in good yields.
- Li, Jin-Heng,Xie, Ye-Xiang,Yin, Du-Lin
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- Pd-Catalyzed desulfitative arylation of olefins by: N -methoxysulfonamide
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A novel Pd-catalyzed protocol for the desulfitative Heck-type reaction of N-methoxy aryl sulfonamides with alkenes was reported. The cross-coupling reaction was performed successfully with a variety of olefins to obtain aryl alkenes. Different substituents on the aromatic ring of N-methoxysulfonamides were also found to be compatible with the reaction conditions. Expectedly, the reaction proceeds through CuCl2-promoted generation of the nitrogen radical and subsequent desulfonylation under thermal conditions to afford the aryl radical for the Pd-catalyzed coupling reaction. N-Methoxysulfonamide was further exploited for the synthesis of symmetrical biaryls in the presence of CuCl2. This journal is
- Ojha, Subhadra,Panda, Niranjan
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supporting information
p. 1292 - 1298
(2022/02/19)
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- Visible Light Induced Aerobic Coupling of Arylboronic Acids Promoted by Hydrazone
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A visible-light-induced oxidative coupling of arylboronic acids has been developed for the synthesis of biaryls. The reaction that employs polydentate hydrazones as the bifunctional catalyst works smoothly under room temperature. It is compatible with a w
- Xia, Hongyu,Wang, Ganghu,Zhao, Dongbo,Zhu, Chunyin
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supporting information
p. 922 - 929
(2022/02/10)
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- Reductive Coupling of Aryl Halides via C—H Activation of Indene
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This paper describes the first case of a reductive coupling reaction with indene, a non-heteroatom olefin used as a reducing agent. The scope of the substrate is wide. The homo-coupling, cross-coupling, and synthesis of 12 and 14-membered rings were realized. The control experiment, indene-product curve and density functional theory calculations showed that the η3-palladium indene intermediate was formed by C—H activation in the presence of cesium carbonate. We speculate that the final product was obtained through a Pd (IV) intermediate or aryl ligand exchange. In addition, we excluded the formation of palladium anion (Pd(0)?) intermediates.
- Zhang, Bo-Sheng,Yang, Ying-Hui,Wang, Fan,Gou, Xue-Ya,Wang, Xi-Cun,Liang, Yong-Min,Li, Yuke,Quan, Zheng-Jun
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p. 1573 - 1579
(2021/05/28)
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- Pd-catalyzed oxidative homocoupling of arylboronic acids in WEPA: A sustainable access to symmetrical biaryls under added base and ligand-free ambient conditions
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Symmetrical and unsymmetrical biaryls comprises a diverse class of biologically eloquent organic compounds. We herein report, a quick and eco-friendly protocol for the synthesis of biaryls by an oxidative (aerobic) homocoupling of arylboronic acids (ABAs) using Pd(OAc)2 in water extract of pomogranate ash (WEPA) as an efficient agro-waste(bio)-derived aqueous (basic) media. The reactions were executed at ambient aerobic conditions in the absence of external base and ligand to result symmetrical biaryls in excellent yields. The use of renewable media with an effective exploitation of waste, short reaction times, excellent yields of products, easy separation of the products, unnecessating the external base, oxidant, ligand or volatile organic solvents and ambient reaction conditions are the vital insights of the present protocol.
- Appa, Rama Moorthy,Lakshmidevi, Jangam,Naidu, Bandameeda Ramesh,Venkateswarlu, Katta
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- Cobalt-catalyzed C(sp2)?CN bond activation: Cross-electrophile coupling for biaryl formation and mechanistic insight
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Herein, we report a cross-electrophile coupling of benzonitrile derivatives and aryl halides with a simple cobalt-based catalytic system under mild conditions to form biaryl compounds. Even though the cobalt catalyst is able to activate the C(sp2)?CN bond alone, the use of the AlMe3 Lewis acid enhances the reactivity of benzonitriles and improves the cross-selectivity with barely any influence on the functional group compatibility. X-ray structure determination of an original low-valent cobalt species combined with catalytic and stoichiometric reactions reveals a catalytically active cobalt(I) species toward the aryl halide partner. On the other hand, experimental insights, including cyclic voltammetry experiments, suggest the involvement of a cobalt complex of a lower oxidation state to activate the benzonitrile derivative. Finally, density functional theory calculations support the proposed mechanistic cycle involving two low-valent cobalt species of different oxidation states to perform the reaction.
- Dorval, Céline,Tricoire, Maxime,Begouin, Jeanne-Marie,Gandon, Vincent,Gosmini, Corinne
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p. 12819 - 12827
(2020/11/18)
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- A Bio-Inspired Magnetically Recoverable Palladium Nanocatalyst for the Ullmann Coupling reaction of Aryl halides and Arylboronic acids In Aqueous Media
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Palladium nanoparticles supported on polydopamine-coated iron oxide nanoparticles (Pd/Fe3O4@PDA) were found to catalyze the Ullmann homocoupling of a wide variety of aryl halides, arylboronic acids and aryldiazonium salts in aqueous media in the presence of randomly methylated β-cyclodextrin (RM-β-CD). The synthesized nanoparticles were characterized by techniques such as TEM, SEM, EDX, XPS, ICP-AES and XRD. The synthesized catalyst can be easily recovered magnetically and reused up to five cycles without any significant loss of activity. This is the first report demonstrating the use of magnetically recoverable catalyst for Ullmann homocoupling reactions of aryl halides, arylboronic acids and aryldiazonium salts in water.
- Dubey, Abhishek V.,Kumar, A. Vijay
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- Nickel-Catalyzed Electrochemical Reductive Homocouplings of Aryl and Heteroaryl Halides: A Useful Route to Symmetrical Biaryls
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Due to their widespread presence in functional materials and pharmaceuticals, biaryls are of fundamental importance in organic chemistry. Methods for the synthesis of symmetrical biaryls generally involve both metallic reduction and transition-metal catalysis. In this work, we show that electroreduction can also constitute a very relevant way to achieve the nickel-catalyzed reductive synthesis of symmetrical biaryl compounds. Therefore, it is demonstrated that both aryl and heteroaryl halides undergo reductive coupling to furnish the corresponding symmetrical biaryls in fair to excellent yields. Reactions are performed under very mild conditions thus ensuring important functional group tolerance.
- Rahil, Rima,Sengmany, Stéphane,Le Gall, Erwan,Léonel, Eric
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p. 146 - 154
(2017/09/28)
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- Palladium-catalyzed reductive homocoupling of aryl sulfonates via cleavage of C─O bond at room temperature
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Palladium-catalyzed reductive homocoupling of aryl sulfonates has been successfully achieved under mild conditions. This transformation is a new method for the homocoupling reaction of aryl sulfonates at room temperature via the cleavage of C─O bonds, thus providing an alternative synthesis of symmetric biaryls. The reported reductive homocoupling reaction is tolerant of many common functional groups regardless of electron-donating or electron-withdrawing nature, making this newly developed transformation important for complementing Ullmann coupling. Experimental Section. Typical procedure for the products.
- Zhong, Shuangling,Chen, Mengxin,Liu, Ge,Sun, Chenggang,Liu, Wencong
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- Copper-free palladium-catalysed desulfinative homocoupling of sodium arylsulfinates under mild and aerobic conditions
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A Pd(II)-catalysed homocoupling of sodium arylsulfinates has been successfully achieved under mild conditions. This transformation is a new method for the homocoupling reaction of sodium arylsulfinates, thus providing an alternative synthesis of symmetric biaryls. The reported homocoupling reaction is tolerant to many common functional groups, such as ester, halo, cyano and nitro and works well in the presence of electron-donating and electron-withdrawing substituents. Notably, the reported desulfinative homocoupling does not require Cu salts, ligands and bases, making this newly developed transformation attractive.
- Zhang, Wei
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- Homocoupling of iodoarenes and bromoalkanes using photoredox gold catalysis: A light enabled Au(III) reductive elimination
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The formation of homocoupled alkane byproducts have been identified in the reduction of bromoalkanes via photoredox gold catalysis with dimeric Au(I) complexes. This prompted further investigation into the mechanism of formation of these byproducts and the diversity of C-X bonds amenable to this transformation. Examples were found when considering bromoalkanes while a wide variety of iodoarenes underwent this process in good to excellent yields. The light enabled homocoupling of iodoarenes made possible by photoredox gold catalysis is reported.
- Tran, Huy,McCallum, Terry,Morin, Mathieu,Barriault, Louis
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supporting information
p. 4308 - 4311
(2016/09/09)
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- Convenient synthesis of organic-electronics-oriented building blocks via on-water and under-air homocoupling of (hetero)aryl iodides
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We report herein an operationally simple homocoupling reaction that targets the convenient synthesis of organic-electronically important building blocks. A variety of synthetically useful bithiophene derivatives and functionalized biphenyls are efficiently prepared by an on-water and under-air protocol using Pd/C as catalyst. We find that Pd/C gives generally higher and cleaner homocoupling conversions than using Pd(OAc)2 in the cases of (hetero)aryl iodides since Pd(OAc)2 triggers more side reactions including dehalogenations and oligomerizations. Under the optimum conditions, a broad range of functional groups such as ester, ketone, aldehyde, nitrile, nitro, chloride, and bromide are well tolerated. We expect the present methodology would make a valuable synthetic contribution towards bridging green chemistry with thiophene-based organic materials.
- Chen, Yi-An,Liu, Ching-Yuan
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p. 74180 - 74188
(2015/09/21)
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- Nickel-catalyzed one-pot deoxygenation and reductive homocoupling of phenols via C-O activation using TCT reagent
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A new method for C-O bond activation of phenolic compounds has been achieved using 2,4,6-trichloro-1,3,5-triazine to utilize in one-pot Ni-catalyzed deoxygenation and reductive homocoupling reactions. With this simple method, phenolic compounds were converted to their corresponding arenes or biaryl compounds under mild conditions. The introduced methodology has a broad scope and demonstrates good functional group compatibility.
- Iranpoor, Nasser,Panahi, Farhad
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supporting information
p. 214 - 217
(2015/01/30)
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- Catalytic desulfitative homocoupling of sodium arylsulfinates in water using PdCl2 as the recyclable catalyst and O2 as the terminal oxidant
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A green and convenient approach to symmetrical biaryls has been developed. The catalytic desulfitative homocoupling of various inexpensive and readily available sodium arylsulfinates in environment-friendly solvent, water, and under clean oxidant, molecular O2, afforded symmetrical biaryls in good yields. What's more, water can hold the noble catalyst PdCl2 for recycling several times easily, and facilitate separating insoluble organic product.
- Rao, Bin,Zhang, Weixi,Hu, Lan,Luo, Meiming
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p. 3436 - 3440
(2013/01/16)
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- Targeting the heat shock protein 90 dimer with dimeric inhibitors
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The design, synthesis, and biological evaluation of conformationally constrained coumermycin A1 analogues are reported. Compounds were evaluated against both breast cancer (SKBr3 and MCF7) and prostate cancer (PC3 mm2, A549, and HT29) cell lines. Non-noviosylated coumermycin A1 analogues that manifest potent antiproliferative activity resulting from Hsp90 inhibition are provided, wherein replacement of the stereochemically complex noviose sugar with readily available piperidine rings resulted in ü100 fold increase in antiproliferative activities as compared to coumermycin A1, producing small molecule Hsp90 inhibitors that exhibit nanomolar activities.
- Kusuma, Bhaskar Reddy,Peterson, Laura B.,Zhao, Huiping,Vielhauer, George,Holzbeierlein, Jeffrey,Blagg, Brian S. J.
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p. 6234 - 6253
(2011/10/31)
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- Homocoupling of arylboronic acids catalyzed by CuCl in air at room temperature
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Homocoupling of arylboronic acids has been successfully carried out by using the inexpensive simple copper salt CuCl as the catalyst in methanol to obtain symmetric biaryls in good to excellent yields. The reaction proceeds with a CuCl loading of 2 mol-% under extremely mild conditions: in air, at room temperature, without the need of any additives such as base, oxidant, or ligand. A simple and efficient CuCl-catalyzed homocoupling of arylboronic acids for the synthesis of symmetrical biaryls is described. The homocoupling reaction takes place with a catalyst loading of at 2 mol-% in economical and easily handled methanol and under extremely mild conditions: in air, at room temperature, without any additives such as base, oxidant, or ligand. Copyright
- Cheng, Guanjun,Luo, Meiming
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experimental part
p. 2519 - 2523
(2011/06/10)
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- Electroreductive generation of recyclable organic reductant from N,N′-dioctyl-4,4′-bipyridinium and Pd-catalyzed reductive coupling of aryl halides
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Electroreduction of N,N′-dioctyl-4,4′-bipyridinium bis(triflimide) [C8V2+][Tf2N-] 2 in THF gave a dark blue solution of the corresponding quinoid C8V0, which worked as an efficient organic reductant for Pd-catalyzed reductive coupling of aryl bromides to give the corresponding biphenyl derivatives in good yields. After usual workup, [C8V 2+][Tf2N-]2 was recovered and reused for generation of the organic reductant C8V0. Georg Thieme Verlag Stuttgart.
- Kuroboshi, Manabu,Kobayashi, Ryoto,Nakagawa, Takayuki,Tanaka, Hideo
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scheme or table
p. 85 - 88
(2009/06/27)
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- Preparation of functionalized aryl- and heteroarylpyridazines by nickel-catalyzed electrochemical cross-coupling reactions
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(Chemical Equation Presented) A general efficient electrochemical method for the preparation of aryl- and heteroarylpyridazines in a nickel-catalyzed cross-coupling reaction of 3-chloro-6-methoxypyridazine and 3-chloro-6- methylpyridazine with a range of functionalized aryl or heteroaryl halides is reported.
- Sengmany, Stephane,Leonel, Eric,Polissaint, Frantz,Nedelec, Jean-Yves,Pipelier, Muriel,Thobie-Gautier, Christine,Dubreuil, Didier
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p. 5631 - 5636
(2008/02/09)
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- Palladium-catalyzed homocoupling and cross-coupling reactions of aryl halides in poly(ethylene glycol)
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The direct coupling of aryl halides to prepare symmetrical and unsymmetrical biaryls were performed successfully in poly(ethylene glycol) (PEG) using Pd(OAc)2 as the catalyst in the absence of other additives or reductants. The selectivity toward biaryl depended on the amount of PEG used. Excessive PEGs induce the increase of hydrodehalogenation product, and the best selectivity to biaryl is obtained when the concentration of the hydroxyl group in PEG achieves 100 mol% relative to aryl halides. The catalyst system could be recycled and reused up to five times with no loss of catalytic activity.
- Wang, Liang,Zhang, Yuhong,Liu, Leifang,Wang, Yanguang
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p. 1284 - 1287
(2007/10/03)
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- Palladium-catalyzed synthesis of biaryls from arylzinc compounds using N-chlorosuccinimide or oxygen as an oxidant
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In the presence of a catalytic amount of Pd2+ or Pd0, oxidative homo-coupling of arylzinc compounds was achieved by the use of N-chlorosuccinimide (NCS) or O2 as an oxidant. Different reaction pathways were involved in the catalytic reactions depending on the oxidants; NCS or O2 probably oxidized I- or Pd0 to I+ or Pd2+, respectively. This reaction disclosed a new and facile synthetic method of biaryls from aryl halides or arenes via arylzinc intermediates.
- Hossain, Kabir M.,Kameyama, Toru,Shibata, Takanori,Takagi, Kentaro
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p. 2415 - 2420
(2007/10/03)
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- A new synthetic method to biaryls from arylzinc iodides using N-chloro-succinimide and a catalytic amount of palladium
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Homo-coupling reactions of aryl- or alkynylzinc iodides were achieved by the use of N-chlorosuccinimide as an oxidant of zinc compounds in the presence of a catalytic amount of Pd.
- Hossain,Shibata,Takagi
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p. 1137 - 1138
(2007/10/03)
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- Formation of cyclopent[a]indene and acenaphthylene from allyl esters of biphenyl mono- and di-carboxylic acids and from biphenyl dicarboxylic anhydrides on flash vacuum pyrolysis at 1000-1100°C
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Flash vacuum pyrolysis at 1000-1100°C of the allyl esters of the three isomeric biphenylcarboxylic acids, of the allyl esters of the 12 biphenyldicarboxylic acids and of the three biphenyldicarboxylic anhydrides gave pyrolysates which were examined by 1H n.m.r. spectroscopy at temperatures below -50°C. In all cases the spectra showed the presence of cyclopent[a]indene and acenaphthylene together with other products. Possible mechanisms for these ring contraction and cyclization processes are discussed and the results of pyrolyses of [2,3-13C2]biphenyl-2,3-dicarboxylic anhydride, and [3,4-13C2]-and (2-2H1)-biphenyl-3,4-dicarboxylic anhydrides are reported.
- Bapat, Jayant B.,Brown, Roger F.C.,Bulmer, Glenn H.,Childs, Trevor,Coulston, Karen J.,Eastwood, Frank W.,Taylor, Dennis K.
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p. 1159 - 1182
(2007/10/03)
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- Aryl Mesylates in Metal-Catalyzed Homocoupling and Cross-Coupling Reactions. 1. Functional Symmetrical Biaryls from Phenols via Nickel-Catalyzed Homocoupling of Their Mesylates
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Aryl sulfonates including mesylate derived from phenols are converted in high yields to biaryls by homocoupling in the presence of catalytic amounts of zero-valent nickel catalysts generated in situ.This reaction provides the most convenient method for the synthesis of many functional symmetrical biaryls and was applied to the preparation of 2,2'-, 3,3'-, and 4,4'-disubstituted biphenyls and other biaryls.The influence of the electronic and steric effects of substituents attached in the ortho, meta, and para positions of aryl sulfonates and the nature of the sulfonate leaving group on the yield of homocoupled product as well as their influence on the extent of various side reactions were investigated.In addition, the influence of the effects of the polarity and dryness of solvent, halide ion source and concentration, and ratio of catalyst and ligand to aryl sulfonate are discussed.
- Percec, Virgil,Bae, Jin-Young,Zhao, Mingyang,Hill, Dale H.
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p. 176 - 185
(2007/10/02)
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- Homocoupling of aryl halides using Nickel(II) complex and zinc in the presence of Et4NI. An efficient method for the synthesis of biaryls and bipyridines
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Reduction of NiX2(PPh3)2 with zinc in the presence of Et4NI gives a nickel catalyst which has been proven to be useful for the coupling of aryl halides. This nickel catalyst can be prepared in THF without an additional triphenylphosphine and is effective for the homocoupling of aryl chlorides, bromides, and iodides to produce biaryls and bipyridines in good yields. The reported new approach provides a simple access to novel derivatives of biaryls and bipyridines.
- Iyoda,Otsuka,Sato,Nisato,Oda
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- Ni(0)-TRIALKYLPHOSPHINE COMPLEXES. EFFICIENT HOMO-COUPLING CATALYST FOR ARYL, ALKENYL, AND HETEROAROMATIC HALIDES.
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Bis(trialkylphosphine)nickel(0) generated in situ from bis(trialkylphosphine)nickel(II) chloride was found to be an effective catalyst for a homo-coupling of aryl, alkenyl, or heteroaromatic halides with zinc powder. The catalytic reaction proceeded very well in NMP or HMPA solvent under mild conditions to afford dehalogenative-coupling products in good yields.
- Takagi,Hayama,Sasaki
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p. 1887 - 1890
(2007/10/02)
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- The in Situ-generated Nickel(0)-catalyzed Reaction of Aryl Halides with Potassium Iodide and Zinc Powder
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The in situ-generated nickel(0) species, presumably atomic nickel, from nickel(II) salt and zinc powder has been proved to be an effective catalyst for the Finkelstein-type displacement reaction of aryl bromides with potassium iodide to give aryl iodides under mild conditions.This species was also effective for the Ullmann-type coupling of bromides or aryl iodides by the use of zinc powder to give biaryls.Furthermore, in the presence of excess nickel(II) salt, the coupling reaction proceeded smoothly, even at an ambient temperature, to give various biaryls in very good yields.
- Takagi, Kentaro,Hayama, Naomi,Inokawa, Saburo
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p. 3691 - 3695
(2007/10/02)
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- Total Syntheses of the meta,meta-Bridged Biphenyls (+/-)-Myricanol and Myricanone, and of an Isomeric Biphenyl Ether, a 14-Oxametaparacyclophane
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The oxidative coupling of 1,7-bis(hydroxyphenyl)heptanoids (2a,b) has been investigated: C-C coupling to meta,meta-bridged biaryls was not observed, but with thallium tris(trifluoroacetate) C-O coupling occurred forming a 14-oxametaparacyclophane analogous to the natural phenols acerogenin-A and galeon.Intramolecular reductive coupling, using tetrakis(triphenylphosphine)nickel(0), of the bis-iodides (11a,b) derived from phenols (2a,b), leads, after deprotection, to the desired meta,meta-bridged biphenyls myricanone and (+/-)-myricanol, albeit in rather low yield.OO-Dimethylmyricanone and (+/-)-OO-dimethylmyricanol were similarly synthesized.Irradiation (254 nm) in alkaline ethanol of the bromides (11g,h) also induced aryl-aryl coupling to form dibenzylmyricanone and (+/-)-dibenzylmyricanol acetate respectively.
- Whiting, Donald A.,Wood, Andrew F.
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p. 623 - 628
(2007/10/02)
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