- Palladium-catalyzed cross-coupling of five-membered heterocyclic silanolates
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(Chemical Equation Presented) The preparation of π-rich 2-aryl heterocycles by palladium-catalyzed cross-coupling of sodium heteroarylsilanolates with aryl iodides, bromides, and chlorides is described. The cross-coupling process was developed through extensive optimization of the following key variables: (1) identification of stable, isolable alkali metal silanolates, (2) identification of conditions for preformation and isolation of silanolate salts, (3) judicious choice in the palladium catalyst/ligand combination, and (4) selection of the protecting group on the nitrogen of indole. It was found that the alkali metal silanolates, either isolated or formed in situ, offered a significant rate enhancement and broader substrate scope over the use of silanols activated by Bronsted bases such as NaOt-Bu. In addition, the optimized conditions for the cross-coupling of 2-indolylsilanolates were readily applied to the cross-coupling of 2-pyrrolyl-, 2-furyl-, and 2-thienylsilanolates.
- Denmark, Scott E.,Baird, John D.,Regens, Christopher S.
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- Synthesis, characterization and X-ray structures of N-heterocyclic carbene palladium complexes based on calix[4]arenes: Highly efficient catalysts towards Suzuki-Miyaura cross-coupling reactions
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A new series of calix[4]arene supported N-heterocyclic carbene palladium complexes were developed and fully characterized. A mono-substituted calix[4]arene was prepared through conventional procedures, following with the attachment of imidazolyl derivative groups to compose the precursors of novel NHCs ligands. Undergoing the alkylation with n-butylbromide and corresponding metallation with palladium and pyridine, original complexes were obtained. After a full characterization in solution and solid state, the evaluation of catalytic activity was taken out in Suzuki-Miyaura cross-coupling reactions, which revealed good performances.
- Ren, Hui,Xu, Yong,Jeanneau, Erwann,Bonnamour, Isabelle,Tu, Tao,Darbost, Ulrich
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- Nickel-catalyzed cross-coupling of arene-or heteroarenecarbonitriles with aryl-or heteroarylmanganese reagents through C-CN bond activation
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The nickel-catalyzed cross-coupling reaction of arene- or heteroarenecarbonitriles with aryl- or heteroarylmanganese reagents via C-CN bond activation has been developed. Both electron-rich and electron-deficient nitriles can be employed as the electrophilic substrates. The reaction tolerates a range of functional groups and aromatic heterocycles. Copyright
- Liu, Ning,Wang, Zhong-Xia
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- New catalysts for Suzuki-Miyaura coupling reactions of heteroatom- substituted heteroaryl chlorides
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(Chemical Equation Presented) The new air-stable PdCl2{PR 2(Ph-R′)}2 complexes, readily prepared from commercial reagents, exhibit unique efficiency as catalysts for the Suzuki-Miyaura coupling reactions of a variety of he
- Guram, Anil S.,Wang, Xiang,Bunel, Emilio E.,Faul, Margaret M.,Larsen, Robert D.,Martinelli, Michael J.
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- Catalytic direct cross-coupling of organolithium compounds with aryl chlorides
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Palladium-catalyzed direct cross-coupling of aryl chlorides with a wide range of (hetero)aryl lithium compounds is reported. The use of Pd-PEPPSI-IPent or Pd2(dba)3/XPhos as the catalyst allows for the preparation of biaryl and heterobiaryl compounds in high yields under mild conditions (room temperature to 40 C) with short reaction times.
- Hornillos, Valentin,Giannerini, Massimo,Vila, Carlos,Fananas-Mastral, Martin,Feringa, Ben L.
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- Organic field-effect transistors based on heterocyclic co-oligomers containing a pyrazine ring
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New oligomers containing a pyrazine unit have been prepared: the bithienyl derivatives afforded p-type FET devices whereas the trifluoromethylphenyl derivatives showed n-type FET behavior. The Royal Society of Chemistry.
- Kojima, Takahiro,Nishida, Jun-Ichi,Tokito, Shizuo,Tada, Hirokazu,Yamashita, Yoshiro
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- One-Pot Dual Catalysis of a Photoactive Coordination Polymer and Palladium Acetate for the Highly Efficient Cross-Coupling Reaction via Interfacial Electron Transfer
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We report herein an exploration of the straightforward one-pot dual-catalysis strategy, i.e., direct combination of a photoactive coordination polymer (CP) with another metal catalyst, for carrying out the desirable photoinduced organic transformation. Th
- Guo, Zhifen,Liu, Xin,Che, Yan,Chen, Dashu,Xing, Hongzhu
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supporting information
p. 2695 - 2705
(2022/02/14)
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- C-H Arylation of Thiophenes with Aryl Bromides by a Parts-per-Million Loading of a Palladium NNC-Pincer Complex
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A palladium NNC-pincer complex efficiently catalyzed the direct arylation of thiophene derivatives with extremely low palladium loadings of the order of parts per million. Thus, the reaction of various thiophenes with aryl bromides in the presence of 25-100 mol ppm of chlorido[(2-phenyl-κ- C 2)-9-phenyl-1,10-phenanthroline-κ 2- N, N ′]palladium(II) NNC-pincer complex, K 2CO 3, and pivalic acid in N, N -dimethyl acetamide afforded the corresponding 2- or 5-arylated thiophenes in good to excellent yields. A combination of the present C-H arylation and Hiyama coupling with the same NNC-pincer complex provides an efficient synthesis of unsymmetrical 2,5-thiophenes with catalyst loadings at mol ppm levels.
- Purta, Anggi Eka,Ichii, Shun,Tazawa, Aya,Uozumi, Yasuhiro
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supporting information
p. 1634 - 1638
(2020/08/28)
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- Potassium trimethylsilanolate enables rapid, homogeneous suzuki-miyaura cross-coupling of boronic esters
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Herein, a mild and operationally simple method for the Suzuki-Miyaura cross-coupling of boronic esters is described. Central to this advance is the use of the organic-soluble base, potassium trimethylsilanolate, which allows for a homogeneous, anhydrous cross-coupling. The coupling proceeds at a rapid rate, often furnishing products in quantitative yield in less than 5 min. By applying this method, a >10-fold decrease in reaction time was observed for three published reactions which required >48 h to reach satisfactory conversion.
- Delaney, Connor P.,Kassel, Vincent M.,Denmark, Scott E.
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- UiO-66 microcrystals catalyzed direct arylation of enol acetates and heteroarenes with aryl diazonium salts in water
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UiO-66 is a classic Metal–organic framework (MOF) that constructed by zirconium cations and terephthalate with high chemical and thermal stability. Using pristine UiO-66 nanocrystals as the catalysts, the carbon–carbon bond formation based on denitrogenat
- Sun, Zhong-Hua,Chen, Wang,Qian, Bing-Bing,Wang, Liang,Yu, Binxun,Chen, Qun,He, Ming-Yang,Zhang, Zhi-Hui
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- Metal-Free Aerobic Oxidative Selective C-C Bond Cleavage in Heteroaryl-Containing Primary and Secondary Alcohols
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A transition-metal-free aerobic oxidative selective C-C bond-cleavage reaction in primary and secondary heteroaryl alcohols is reported. This reaction was highly efficient and tolerated various heteroaryl alcohols, generating a carboxylic acid derivative and a neutral heteroaromatic compound. Experimental studies combined with density functional theory calculations revealed the mechanism underlying the selective C-C bond cleavage. This strategy also provides an alternative simple approach to carboxylation reaction.
- Xia, Anjie,Qi, Xueyu,Mao, Xin,Wu, Xiaoai,Yang, Xin,Zhang, Rong,Xiang, Zhiyu,Lian, Zhong,Chen, Yingchun,Yang, Shengyong
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supporting information
(2019/05/07)
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- Synthesis of heterobiaryls via Suzuki-Miyaura coupling reaction of potassium aryltrifluoroborates with heteroaryl halides in aqueous systems
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A variety of heterobiaryl compounds have been synthesized by the Suzuki-Miyaura coupling reactions of heteroaryl halides with potassium aryltrifluoroborates. Pd (OAc)2 was found to be highly efficient for the Suzuki-Miyaura coupling reactions of various heteroaryl halides with potassium aryltrifluoroborates in aqueous systems, delivering the corresponding heterobiaryl compounds in good to excellent yields.
- Liu, Leifang,Zhao, Kai,Li, Wenbo,Liu, Mingli,Chen, Yuting,Dong, Yan
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- Continuous Visible-Light Photoflow Approach for a Manganese-Catalyzed (Het)Arene C?H Arylation
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Manganese photocatalysts enabled versatile room-temperature C?H arylation reactions by means of continuous visible-light photoflow, thus allowing for efficient C?H arylations in 30 minutes with ample scope. The robustness of the manganese-catalyzed photoflow strategy was shown by visible light-induced gram-scale synthesis, clearly outperforming the batch performance.
- Liang, Yu-Feng,Steinbock, Ralf,Yang, Long,Ackermann, Lutz
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supporting information
p. 10625 - 10629
(2018/08/01)
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- BENZOBISTHIADIAZOLE COMPOUND, ORGANIC THIN FILM CONTAINING THE SAME, AND ORGANIC SEMICONDUCTOR ELEMENT
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PROBLEM TO BE SOLVED: To provide a benzobisthiadiazole compound usable as an organic semiconductor material excellent in electron transportability and operation stability. SOLUTION: The benzobisthiadiazole compound is represented by formula (I). (X1 and X2 are each independently an alkynylene group, a thienylene group, or a thiazolylene group; Ar1 and Ar2 are each independently a pyridyl group substituted with R, an N-oxypyridyl group substituted with R, a pyrimidinyl group substituted with R, a pyrazyl group substituted with R, or a phenyl group substituted with R; R is an electron-withdrawing substituent; and when both X1 and X2 are thienylene groups, Ar1 and Ar2 are each independently a pyridyl group substituted with R, an N-oxypyridyl group substituted with R, a pyrimidinyl group substituted with R, or a pyrazyl group substituted with R). SELECTED DRAWING: None COPYRIGHT: (C)2018,JPOandINPIT
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Paragraph 0117; 0160; 0161
(2018/06/30)
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- End-Capping Groups for Small-Molecule Organic Semiconducting Materials: Synthetic Investigation and Photovoltaic Applications through Direct C–H (Hetero)arylation
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A Pd-catalyzed C–H (hetero)arylation methodology has been optimized for the efficient synthesis of various useful end-capping groups that are widely applied in small-molecule optoelectronic materials. We report herein the synthesis of a broad scope of target molecules ranging from donor-type through acceptor-type to hybrid-type end-capping groups. To demonstrate their application in dye-sensitized solar cells, we have designed two new D–A–π–A′-type organic sensitizers (CYL-3 and CYL-4), which were synthesized in a step-economic manner by sequential C–H arylations using the facilely obtained end-capping groups. The devices based on CYL-3 and CYL-4 give Vocvalues of 0.67–0.71 V, Jscvalues of 10.07–11.63 mA cm–2, and FF values of 70.6–72.9 %, which correspond to overall power conversion efficiencies of 4.76–6.02 %. This work is expected to become a practical synthetic alternative allowing materials scientists to access small-molecule organic materials in fewer synthetic transformations.
- Lu, Te-Jui,Lin, Po-Han,Lee, Kun-Mu,Liu, Ching-Yuan
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p. 111 - 123
(2017/01/14)
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- Synthesis of Biaryls through Nickel-Catalyzed Suzuki-Miyaura Coupling of Amides by Carbon-Nitrogen Bond Cleavage
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The first Ni-catalyzed Suzuki-Miyaura coupling of amides for the synthesis of widely occurring biaryl compounds through N-C amide bond activation is reported. The reaction tolerates a wide range of electron-withdrawing, electron-neutral, and electron-donating substituents on both coupling partners. The reaction constitutes the first example of the Ni-catalyzed generation of aryl electrophiles from bench-stable amides with potential applications for a broad range of organometallic reactions. Breaking and making: The first nickel-catalyzed Suzuki-Miyaura coupling of amides for the synthesis of biaryl compounds through N-C amide bond cleavage is reported. The reaction tolerates a wide range of sensitive and electronically diverse substituents on both coupling partners.
- Shi, Shicheng,Meng, Guangrong,Szostak, Michal
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supporting information
p. 6959 - 6963
(2016/06/13)
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- 2-Aryl-indenylphosphine ligands: Design, synthesis and application in Pd-catalyzed Suzuki-Miyaura coupling reactions
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A focused library of phosphine ligands was constructed for structural optimization. The catalyst can be used to perform the Suzuki-Miyaura cross-coupling reaction of aryl and heteroaryl chlorides.
- Lian, Ze-Yu,Yuan, Jia,Yan, Meng-Qi,Liu, Yan,Luo, Xue,Wu, Qing-Guo,Liu, Sheng-Hua,Chen, Jian,Zhu, Xiao-Lei,Yu, Guang-Ao
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supporting information
p. 10090 - 10094
(2016/11/06)
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- Kinetic Studies on the Palladium(II)-Catalyzed Oxidative Cross-Coupling of Thiophenes with Arylboron Compounds and Their Mechanistic Implications
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Reaction orders for the key components in the palladium(II)-catalyzed oxidative cross-coupling between phenylboronic acid and ethyl thiophen-3-yl acetate were obtained by the method of initial rates. It turned out that the reaction rate not only depended on the concentration of palladium trifluoroacetate (reaction order: 0.97) and phenylboronic acid (reaction order: 1.26), but also on the concentration of the thiophene (reaction order: 0.55) and silver oxide (reaction order: -1.27). NMR spectroscopy titration studies established the existence of 1:1 complexes between the silver salt and both phenylboronic acid and ethyl thiophen-3-yl acetate. A low inverse kinetic isotope effect (kH/kD=0.93) was determined upon employing the 4-deuterated isotopomer of ethyl thiophen-3-yl acetate and monitoring its reaction to the 4-phenyl-substituted product. A Hammett analysis performed with para-substituted 2-phenylthiophenes gave a negative ρ value for oxidative cross-coupling with phenylboronic acid. Based on the kinetic data and additional evidence, a mechanism is suggested that invokes transfer of the phenyl group from phenylboronic acid to a 1:1 complex of palladium trifluoroacetate and thiophene as the rate-determining step. Proposals for the structure of relevant intermediates are made and discussed.
- Schnapperelle, Ingo,Breitenlechner, Stefan,Bach, Thorsten
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supporting information
p. 18407 - 18416
(2015/12/24)
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- AgONO-Assisted Direct C-H Arylation of Heteroarenes with Anilines
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A novel copper-catalyzed C-H arylation of heteroarenes with anilines by an in situ diazonium reaction is established by using silver nitrite (AgONO) as an unconventional nitrosating reagent under acid-free conditions. It provides a complementary approach for the C-H arylation of electron-rich heteroarenes with aromatic amines affording a variety of heterobiaryls in moderate to good yields.
- Gowrisankar, Saravanan,Seayad, Jayasree
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supporting information
p. 12754 - 12758
(2015/03/30)
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- Copper-catalyzed Hiyama coupling of (hetero)aryltriethoxysilanes with (hetero)aryl iodides
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A CuI-catalyzed Hiyama coupling was achieved, which proceeds in the absence of an ancillary ligand for aryl-heteroaryl and heteroaryl-heteroaryl couplings. A P,N-ligand is required to obtain the best product yields for aryl-aryl couplings. In addition to facilitating transmetalation, CsF is also found to function as a stabilizer of the [CuAr] species, potentially generated as an intermediate after transmetalation of aryltriethoxysilanes with Cu I-catalysts in the absence of ancillary ligands.
- Gurung, Santosh K.,Thapa, Surendra,Vangala, Adarsh S.,Giri, Ramesh
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supporting information
p. 5378 - 5381
(2013/11/06)
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- Palladium-catalyzed intermolecular desulfinylative cross-coupling of heteroaromatic sulfinates
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Beauty lies in simplicity: An efficient and environmentally benign palladium-catalyzed protocol has been developed using a sulfinate as a nucleophilic coupling partner. The sulfinate position is arylated chemoselectively in very good yields. The bench-stable, non-hygroscopic heteroaromatic sulfinate salts rapidly undergo cross-coupling without the need of a co-catalyst, base, or additives (see scheme; mw=microwave). Copyright
- Sévigny, Stéphane,Forgione, Pat
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supporting information
p. 2256 - 2260
(2013/03/28)
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- Efficient desulfinylative cross-coupling of thiophene and furan sulfinates with aryl bromides in aqueous media
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This letter describes the development of an environmentally benign palladium-catalyzed cross-coupling reaction using heteroaromatic sulfinates as nucleophilic coupling partners in aqueous media. This method accesses aryl-substituted heteroaromatics in very good yields chemoselectively without the need for base, additives or co-catalysts.
- Sévigny, Stéphane,Forgione, Pat
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supporting information
p. 589 - 592
(2013/04/10)
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- THIENOPYRAZINE COMPOUND AND FIELD EFFECT TRANSISTOR CONTAINING SAME
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Disclosed is a thienopyrazine compound which is useful for an organic semiconductor material. Also disclosed are: an organic field effect transistor, which comprises an organic semiconductor layer that is easily produced from an organic semiconductor material containing the thienopyrazine compound by a coating method or a printing method, and which exhibits high carrier mobility and high on/off current ratio; and an organic field effect transistor which has ambipolar characteristics. The thienopyrazine compound is represented by the chemical formula (I) wherein Ar1 and Ar2 each represents an aryl group, and R1 and R2 each independently represents a hydrogen atom, an alkyl group or an aryl group; or alternatively R1 and R2 represent a group having a ring formed by combining R1 and R2 together.
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Page/Page column 11-12
(2012/11/06)
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- Room-temperature Suzuki-Miyaura coupling of heteroaryl chlorides and tosylates
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Suzuki-Miyaura coupling of heteroaryls is an important method for the preparation of compound libraries for medicinal chemistry and materials research. Although many catalysts have been developed, none of them have been generally applicable to the coupling reactions of heteroaryl chlorides and tosylates at room temperature. We discovered that a catalyst combination of Pd(OAc)2 and XPhos (2-dicyclohexylphosphanyl-2',4',6'- triisopropylbiphenyl) could efficiently catalyze these couplings. Besides the choice of catalyst, the use of hydroxide bases in an aqueous alcoholic solvent was essential for fast couplings. These conditions promoted fast release of active catalyst (XPhos)Pd0, and accelerated the transmetalation in the catalytic cycle. Most of the major families of heteroaryl chlorides (31 examples) and tosylates (17 examples) reached full conversion within minutes to hours at room temperature. The method could be easily scaled up for gram-scale synthesis. Furthermore, we examined the relative reactivity of coupling partners in whole reactions. Electron-rich heteroaryl chlorides and tosylates reacted more slowly than electron-deficient ones, in the order of indole, pyrrole furan, thiophene > pyridine. Similarly, electron-deficient arylboronic acids were less reactive than electron-neutral and electron-rich ones. The reactivity trends from this study can help to choose appropriate coupling partners for Suzuki reactions.
- Yang, Junfeng,Liu, Sijia,Zheng, Jian-Feng,Zhou, Jianrong
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supporting information
p. 6248 - 6259,12
(2020/09/16)
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- Discovery of Potent, Selective, and Orally Active Carboxylic Acid Based Inhibitors of Matrix Metalloproteinase-13
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The matrix metalloproteinase enzyme MMP-13 plays a key role in the degradation of type II collagen in cartilage and bone in osteoarthritis (OA). An effective MMP-13 inhibitor would therefore be a novel disease modifying therapy for the treatment of arthritis. Our efforts have resulted in the discovery of a series of carboxylic acid inhibitors of MMP-13 that do not significantly inhibit the related MMP-1 (collagenase-1) or tumor necrosis factor-α (TNF-α) converting enzyme (TACE). It has previously been suggested (but not proven) that inhibition of the latter two enzymes could lead to side effects. A promising carboxylic acid lead 9 was identified and a convergent synthesis developed. This paper describes the optimization of 9 and the identification of a compound 24f for further development. Compound 24f is a subnanomolar inhibitor of MMP-13 (IC50 value 0.5 nM and Ki of 0.19 nM) having no activity against MMP-1 or TACE (IC50 of >10000 nM). Furthermore, in a rat model of MMP-13-induced cartilage degradation, 24f significantly reduced proteoglycan release following oral dosing at 30 mg/kg (75% inhibition, p 0.05) and at 10 mg/kg (40% inhibition, p 0.05).
- Monovich, Lauren G.,Tommasi, Ruben A.,Fujimoto, Roger A.,Blancuzzi, Vincent,Clark, Kirk,Cornell, Wendy D.,Doti, Robert,Doughty, John,Fang, James,Farley, David,Fitt, John,Ganu, Vishwas,Goldberg, Ronald,Goldstein, Robert,Lavoie, Stacey,Kulathila, Raviraj,Macchia, William,Parker, David T.,Melton, Richard,O'Byrne, Elizabeth,Pastor, Gary,Pellas, Theodore,Quadros, Elizabeth,Reel, Noela,Roland, Dennis M.,Sakane, Yumi,Singh, Hem,Skiles, Jerry,Somers, Joseph,Toscano, Karen,Wigg, Andrew,Zhou, Siyuan,Zhu, Lijuan,Shieh, Wen-Chung,Xue, Song,McQuire, Leslie W.
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supporting information; experimental part
p. 3523 - 3538
(2010/03/30)
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- Microwave-assisted Suzuki coupling reactions with an encapsulated palladium catalyst for batch and continuous-flow transformations
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This article describes the design, optimisation and development of a Suzuki cross-coupling protocol mediated by an efficient palladium-en-capsulated catalyst (Pd EnCat) under microwave irradiation. The methodology has been used in both batch mode for classical library preparation and in continuous-flow applications furnishing multigram quantities of material. Described is a method that uses direct focused microwave heating whilst applying an external cooling source. This enables a lower than normal bulk temperature to be maintained throughout the reaction period leading to significant improvements in the overall yield and purity of the reaction products. Additional aspects of this novel heating protocol are discussed in relation to the prolonged lifetime and enhanced reactivity of the immobilised catalyst system.
- Baxendale, Ian R.,Griffiths-Jones, Charlotte M.,Ley, Steven V.,Tranmer, Geoffrey K.
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p. 4407 - 4416
(2008/02/07)
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- Palladium-catalyzed cross-coupling reactions of heterocyclic silanolates with substituted aryl iodides and bromides
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Sodium silanolates derived from a number of heterocyclic silanols undergo cross-coupling with a variety of aromatic iodides and bromides under mild conditions. In situ deprotonation of the silanols with an equivalent amount of sodium hydride in toluene ge
- Denmark, Scott E.,Baird, John D.
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p. 793 - 795
(2007/10/03)
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- An amphiphilic resin-supported palladium catalyst for high-throughput cross-coupling in water
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(figure presented) The Suzuki-Miyaura coupling of aryl halides (8 varieties) and aryl-or vinylboronic acids (12 varieties) took place in water in the presence of a palladium complex of an amphiphilic polystyrene-poly(ethylene glycol) copolymer resin-supported N-anchored 2-aza-1,3-bis(diphenylphosphino)-propane ligand and potassium carbonate to give uniform and quantitative yields of the corresponding biaryls (96 varieties).
- Uozumi, Yasuhiro,Nakai, Yasushi
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p. 2997 - 3000
(2007/10/03)
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- Piperazine compounds as inhibitors of MMP or TNF
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A compound of formula (I) wherein A is a sulfonyl or a carbonyl; R1is an optionally substituted aryl, an optionally substituted heterocyclic group, an optionally substituted lower alkyl or an optionally substituted lower alkenyl; R2is a hydrogen, an optionally substituted lower alkyl, an optionally substituted aryl or an optionally substituted heterocyclic group; R3is an optionally substituted lower alkyl, an optionally substituted lower alkoxy, an optionally substituted aryloxy, an optionally substitued lower alkenyl, an optionally substituted aryl, an optionally substituted heterocyclic group or an optionally substitued amino; R4is a hydrogen, an optionally substituted lower alkyl, an optionally substituted aryl or an optionally substituted heterocyclic group; R5is a hydrogen, an optionally substituted lower alkyl, an optionally substituted aryl or an optionally substituted heterocyclic group; and R10is a hydroxy or a protected hydroxy, and a pharmaceutically acceptable salt thereof. The compound of the present invention is useful as a medicament for prophylactic and therapeutic treatment of MMP- or TNFα-mediated diseases.
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