- Scalable Negishi Coupling between Organozinc Compounds and (Hetero)Aryl Bromides under Aerobic Conditions when using Bulk Water or Deep Eutectic Solvents with no Additional Ligands
-
Pd-catalyzed Negishi cross-coupling reactions between organozinc compounds and (hetero)aryl bromides have been reported when using bulk water as the reaction medium in the presence of NaCl or the biodegradable choline chloride/urea eutectic mixture. Both C(sp3)-C(sp2) and C(sp2)-C(sp2) couplings have been found to proceed smoothly, with high chemoselectivity, under mild conditions (room temperature or 60 °C) in air, and in competition with protonolysis. Additional benefits include very short reaction times (20 s), good to excellent yields (up to 98 %), wide substrate scope, and the tolerance of a variety of functional groups. The proposed novel protocol is scalable, and the practicability of the method is further highlighted by an easy recycling of both the catalyst and the eutectic mixture or water.
- Dilauro, Giuseppe,Azzollini, Claudia S.,Vitale, Paola,Salomone, Antonio,Perna, Filippo M.,Capriati, Vito
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supporting information
p. 10632 - 10636
(2021/04/09)
-
- Design of Benzimidazolyl Phosphines Bearing AlterableP,OorP,N-Coordination: Synthesis, Characterization, and Insights into Their Reactivity
-
A new series of hemilabile benzimidazolyl phosphines is reported. Entities in this ligand family can be easily assembled and prepared on a large scale via a simple one-pot procedure. X-ray crystallographic analyses show that the Pd metal center can coordinate in different fashions, where it relies on the size of the ?PR2group. With the same ligand scaffold, the ligand having a ?PCy2moiety displays better efficiency in expediting aromatic C-C bond-coupling reactions, while the ligand associated with a ?P-t-Bu2group, in contrast, promotes C-N bond-forming reactions.
- Wong, Shun Man,Choy, Pui Ying,Zhao, Qingyang,Yuen, On Ying,Yeung, Chung Chiu,So, Chau Ming,Kwong, Fuk Yee
-
supporting information
p. 2265 - 2271
(2021/05/05)
-
- Generation of Alkyl Radical through Direct Excitation of Boracene-Based Alkylborate
-
The generation of tertiary, secondary, and primary alkyl radicals has been achieved by the direct visible-light excitation of a boracene-based alkylborate. This system is based on the photophysical properties of the organoboron molecule. The protocol is applicable to decyanoalkylation, Giese addition, and nickel-catalyzed carbon-carbon bond formations such as alkyl-aryl cross-coupling or vicinal alkylarylation of alkenes, enabling the introduction of various C(sp3) fragments to organic molecules.
- Hashizume, Daisuke,Hosoya, Takamitsu,Nakamura, Kei,Ohmiya, Hirohisa,Sato, Yukiya,Sumida, Yuto
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supporting information
p. 9938 - 9943
(2020/06/27)
-
- Boracene-based alkylborate enabled Ni/Ir hybrid catalysis
-
Boracene-based alkylborate enabled visible light-mediated metallaphotoredox catalysis. The directly excited borate was easily oxidatively quenched by an excited Ir photoredox catalyst. Ni/Ir hybrid catalysis afforded the products under significantly low i
- Hosoya, Takamitsu,Miyamoto, Yusuke,Ohmiya, Hirohisa,Sato, Yukiya,Sumida, Yuto
-
supporting information
p. 6598 - 6601
(2020/10/02)
-
- Synthesis method of primary amine hydrochloride
-
The invention discloses a synthesis method of primary amine hydrochloride. According to the synthesis method, in the presence of a gold complex, water and alkyne carry out catalytic hydrolysis to generate ketones, and then ketones and ammonium formate are catalyzed by a rhodium complex to generate primary amine. Compared with a conventional primary amine synthesis method, the synthesis method hasthe advantages that no alkali is added during the reaction process, no side product is generated, the atomic economy is good, the reaction conditions are mild, and the synthesis method has a wide prospect.
- -
-
Paragraph 0084-0087
(2019/03/09)
-
- The Role of LiBr and ZnBr2 on the Cross-Coupling of Aryl Bromides with Bu2Zn or BuZnBr
-
The impact of LiBr and ZnBr2 salts on the Negishi coupling of alkylZnBr and dialkylzinc nucleophiles with both electron-rich and -poor aryl electrophiles has been examined. Focusing only on the more difficult coupling of deactivated (electron-rich) oxidative addition partners, LiBr promotes coupling with BuZnBr, but does not have such an effect with Bu2Zn. The presence of exogenous ZnBr2 shuts down the coupling of both BuZnBr and Bu2Zn, which has been shown before with alkyl electrophiles. Strikingly, the addition of LiBr to Bu2Zn reactions containing exogenous ZnBr2 now fully restores coupling to levels seen without any salt present. This suggests that there is a very important interaction between LiBr and ZnBr2. It is proposed that Lewis acid adducts are forming between ZnBr2 and the electron-rich Pd0 centre and the bromide from LiBr forms inorganic zincates that prevent the catalyst from binding to ZnBr2. This idea has been supported by catalyst design as chlorinating the backbone of the NHC ring of Pd-PEPPSI-IPent to produce Pd-PEPPSI-IPentCl catalyst now gives quantitative conversion, up from a ceiling of only 50 % with the former catalyst.
- Eckert, Philip,Organ, Michael G.
-
supporting information
p. 15751 - 15754
(2019/11/16)
-
- Design, synthesis and biological evaluation of novel aryldiketo acids with enhanced antibacterial activity against multidrug resistant bacterial strains
-
Antimicrobial resistance (AMR) is a major health problem worldwide, because of ability of bacteria, fungi and viruses to evade known therapeutic agents used in treatment of infections. Aryldiketo acids (ADK) have shown antimicrobial activity against several resistant strains including Gram-positive Staphylococcus aureus bacteria. Our previous studies revealed that ADK analogues having bulky alkyl group in ortho position on a phenyl ring have up to ten times better activity than norfloxacin against the same strains. Rational modifications of analogues by introduction of hydrophobic substituents on the aromatic ring has led to more than tenfold increase in antibacterial activity against multidrug resistant Gram positive strains. To elucidate a potential mechanism of action for this potentially novel class of antimicrobials, several bacterial enzymes were identified as putative targets according to literature data and pharmacophoric similarity searches for potent ADK analogues. Among the seven bacterial targets chosen, the strongest favorable binding interactions were observed between most active analogue and S. aureus dehydrosqualene synthase and DNA gyrase. Furthermore, the docking results in combination with literature data suggest that these novel molecules could also target several other bacterial enzymes, including prenyl-transferases and methionine aminopeptidase. These results and our statistically significant 3D QSAR model could be used to guide the further design of more potent derivatives as well as in virtual screening for novel antibacterial agents.
- Cvijeti?, Ilija N.,Verbi?, Tatjana ?.,Ernesto de Resende, Pedro,Stapleton, Paul,Gibbons, Simon,Jurani?, Ivan O.,Drakuli?, Branko J.,Zloh, Mire
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p. 1474 - 1488
(2017/11/17)
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- Design, synthesis and structure-based optimization of novel isoxazole-containing benzamide derivatives as FtsZ modulators
-
Antibiotic resistance among clinically significant bacterial pathogens is becoming a prevalent threat to public health, and new antibacterial agents with novel mechanisms of action hence are in an urgent need. Utilizing computational docking method and structure-based optimization strategy, we rationally designed and synthesized two series of isoxazol-3-yl- and isoxazol-5-yl-containing benzamide derivatives that targeted the bacterial cell division protein FtsZ. Evaluation of their activity against a panel of Gram-positive and -negative pathogens revealed that compounds B14 and B16 that possessed the isoxazol-5-yl group showed strong antibacterial activity against various testing strains, including methicillin-resistant Staphylococcus aureus and penicillin-resistant S. aureus. Further molecular biological studies and docking analyses proved that the compound functioned as an effective inhibitor to alter the dynamics of FtsZ self-polymerization via a stimulatory mechanism, which finally terminated the cell division and caused cell death. Taken together, these results could suggest a promising chemotype for development of new FtsZ-targeting bactericidal agent.
- Bi, Fangchao,Song, Di,Zhang, Nan,Liu, Zhiyang,Gu, Xinjie,Hu, Chaoyu,Cai, Xiaokang,Venter, Henrietta,Ma, Shutao
-
-
- Photoredox-Assisted Reductive Cross-Coupling: Mechanistic Insight into Catalytic Aryl-Alkyl Cross-Couplings
-
Here, we describe a photoredox-assisted catalytic system for the direct reductive coupling of two carbon electrophiles. Recent advances have shown that nickel catalysts are active toward the coupling of sp3-carbon electrophiles and that well-controlled, light-driven coupling systems are possible. Our system, composed of a nickel catalyst, an iridium photosensitizer, and an amine electron donor, is capable of coupling halocarbons with high yields. Spectroscopic studies support a mechanism where under visible light irradiation the Ir photosensitizer in conjunction with triethanolamine are capable of reducing a nickel catalyst and activating the catalyst toward cross-coupling of carbon electrophiles. The synthetic methodology developed here operates at low 1 mol % catalyst and photosensitizer loadings. The catalytic system also operates without reaction additives such as inorganic salts or bases. A general and effective sp2-sp3 cross-coupling scheme has been achieved that exhibits tolerance to a wide array of functional groups.
- Paul, Avishek,Smith, Mark D.,Vannucci, Aaron K.
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p. 1996 - 2003
(2017/02/26)
-
- Asymmetric Autoamplification in the Oxidative Kinetic Resolution of Secondary Benzylic Alcohols Catalyzed by Manganese Complexes
-
Herein, chiral Mn–aminopyridine complexes have been shown to catalyze the oxidation of alkylarenes to enantiomerically enriched 1-arylalkanols with hydrogen peroxide. The observed enantiomeric excess values result from the direct enantioselective benzylic C?H hydroxylation, accompanied by stereoconvergent oxidative kinetic resolution of the resulting alcohol. Testing several (S,S)-bipyrrolidine derived Mn complexes has revealed a novel catalyst (6) that exhibits the best kinetic resolution in the series (krel up to 8.8), along with sufficient reactivity and efficiency (>1000 catalytic turnovers). The mechanistic study of the Mn-mediated alcohol oxidation witnesses electrophilic active species (ρ=?1.2), with rate-limiting H abstraction (kH/kD=2.2), followed by oxygen rebound and dehydration of the resulting gem-diol to form the ketone. Intriguingly, while for the resolution of the relatively bulky 1,2-diphenylethanol, krel is virtually constant throughout the reaction, for less bulky alcohols, krel increases with increasing conversion, in line with the rising optical purity of the 1-arylalkanol. The latter participates in the oxidation as an auxiliary ligand, assisting the chiral recognition. This effect is related to the previously described asymmetric autocatalysis and asymmetric autoinduction, but is not identical with either of those, with the differences being discussed. To unambiguously identify this effect, the term asymmetric autoamplification (chiral autoamplification) is proposed.
- Talsi, Evgenii P.,Samsonenko, Denis G.,Bryliakov, Konstantin P.
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p. 2599 - 2607
(2017/07/12)
-
- Method for generating methyl ketone from olefin through catalytic oxidation
-
The invention discloses a method for generating methyl ketone from olefin through catalytic oxidation. The method comprises the following preparation steps: (1) sequentially adding an olefin compound, a palladium catalyst and an organic solvent into a reaction vessel, mixing and stirring, and heating; (2) then respectively adding acid solution and an oxidizing agent into the reaction vessel, continuously stirring, carrying out constant temperature reaction, after the reaction is finished, cooling, and filtering; (3) extracting filtrate obtained through filtration in the step (2) with ethyl acetate, and carrying out reduced pressure distillation and concentration on an organic phase of extracting solution; and recycling and carrying out activation treatment on a filter cake; and (4) carrying out purification treatment on concentrate obtained in the step (3), so that the target product is obtained. The method disclosed by the invention has the characteristics of simple preparation technology, mild reaction conditions, high selectivity and yield and environmental friendliness.
- -
-
Paragraph 0037
(2017/11/29)
-
- Nickel-Catalyzed Reductive Cross-Coupling of Aryl Triflates and Nonaflates with Alkyl Iodides
-
A nickel-catalyzed cross-electrophile coupling of aryl triflates and nonaflates with alkyl iodides using manganese(0) as a reductant is described. The method is applicable to the reductive alkylation of various aryl sulfonates, including o -borylaryl triflate, which enabled efficient construction of diverse alkylated arenes under mild conditions.
- Sumida, Yuto,Sumida, Tomoe,Hosoya, Takamitsu
-
p. 3590 - 3601
(2017/08/16)
-
- A facile synthesis of a solvent-dispersible magnetically recoverable Pd0 catalyst for the C-C coupling reaction
-
Solvent-dispersible magnetite particles (Fe3O4) functionalized with dopamine (DA) and N,N-dimethylglycine (DMG) were successfully prepared by a one-pot synthesis method with environment-friendly materials. Then Pd0 nanoparticles were anchored onto the functionalized Fe3O4. The prepared materials were thoroughly characterized by TEM, XRD, XPS, FT-IR and VSM. The resultant magnetically recoverable Pd catalyst exhibited excellent catalytic activity for the C-C coupling reaction. In addition, this catalyst revealed high efficiency and stability during recycling stages. This work should be useful for the development and application of a magnetically recoverable Pd catalyst on the basis of green chemistry principles.
- Wu, Li,Yuan, Bin,Liu, Mengmeng,Huo, Hongfei,Long, Yu,Ma, Jiantai,Lu, Gongxuan
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p. 56028 - 56034
(2016/07/06)
-
- Zeolite y nanoparticle assemblies with high activity in the direct hydration of terminal alkynes
-
A strong acidic zeolite Y nanoparticle assembly (HNANO-Y) with a micro-meso-macroporous structure was synthesized and used as a highly efficient heterogeneous catalyst for the hydration of alkynes to prepare ketone compounds, as compared to acidic mesoporous zeolite ZSM-5 and Beta catalysts. This feature should be assigned to the fact that the micro-meso-macroporous structure in the HNANO-Y benefits mass transfer and the strongly acidic sites on HNANO-Y facilitate alkyne hydration activity. The catalyst can be reused six times without loss of activity.
- Xu, Shuling,Yun, Zhi,Feng, Yu,Tang, Ting,Fang, Zhongxue,Tang, Tiandi
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p. 69822 - 69827
(2016/08/06)
-
- Catalytic hydration of alkynes to ketones by a salen-gold(III) complex
-
A general atom-economical approach for the synthesis of ketones is demonstrated through hydration of a wide range of alkynes catalyzed by a salen-gold(III) complex in the presence of trifluoroacetic acid as the cocatalyst. Various terminal and internal alkynes were suitable substrates for the catalytic system.
- Chen, Tingting,Cai, Chun
-
p. 102 - 104
(2015/03/18)
-
- Silver-containing microemulsion as a high-efficient and recyclable catalytic system for hydration of alkynes
-
A silver-catalyzed highly efficient and regioselective synthesis of ketones from a wide range of alkynes is described. The reaction is dramatically accelerated by its performance in aqueous emulsion, which is self-assembled by the addition of silver perfluorooctanesulfonate (1) and perfluorooctanesulfonic acid (PFOS) to water. The reaction is conducted under convenient conditions with broad substrate scope, including a variety of aromatic and aliphatic terminal alkynes and internal alkynes. Furthermore, the air- and light-stable silver catalytic microemulsion can be reused for 4 times with minimal change in catalytic efficiency.
- Dong, Qizhi,Li, Ningbo,Qiu, Renhua,Wang, Jinying,Guo, Cancheng,Xu, Xinhua
-
p. 122 - 127
(2015/10/12)
-
- A Polymer-Bound Monodentate-P-Ligated Palladium Complex as a Recyclable Catalyst for the Suzuki-Miyaura Coupling Reaction of Aryl Chlorides
-
A three-fold cross-linked polymer-bound phosphine (POL-Ph3P) with high phosphorus content has been prepared. The phosphorus-containing polymer forms a monodentate-P-ligated palladium complex, which shows excellent activity in Suzuki-Miyaura cross-coupling reactions of aryl chlorides. Importantly, the catalyst Pd/POL-Ph3P is highly stable and can be reused for at least 10 times without losing reactivity.
- Zhou, Yun-Bing,Li, Cun-Yao,Lin, Min,Ding, Yun-Jie,Zhan, Zhuang-Ping
-
supporting information
p. 2503 - 2508
(2015/08/18)
-
- 5-Aryl-1H-pyrazole-3-carboxylic acids as selective inhibitors of human carbonic anhydrases IX and XII
-
Inhibitory activity of a congeneric set of 23 phenyl-substituted 5-phenyl-pyrazole-3-carboxylic acids toward human carbonic anhydrase (hCA, EC 4.2.1.1) isoforms I, II, IX and XII was evaluated by a stopped-flow CO2 hydrase assay. These compounds exerted a clear, selective inhibition of hCA IX and XII over hCAI and II, with Ki in two to one digit micromolar concentrations (4-50 μM). Derivatives bearing bulkier substituents in para-position of the phenyl ring inhibited hCA XII at one-digit micromolar concentrations, while derivatives having alkyl substituents in both ortho- and meta-positions inhibited hCA IX with Kis ranging between 5 and 25 μM. Results of docking experiments offered a rational explanation on the selectivity of these compounds toward CA IX and XII, as well as on the substitution patterns leading to best CA IX or CA XII inhibitors. By examining the active sites of these four isoforms with GRID generated molecular-interaction fields, striking differences between hCA XII and the other three isoforms were observed. The field of hydrophobic probe (DRY) appeared significantly different in CA XII active site, comparing to other three isoforms studied. To the best of our knowledge such an observation was not reported in literature so far. Considering the selectivity of these carboxylates towards membrane-associated over cytosolic CA isoforms, the title compounds could be useful for the development of isoform-specific non-sulfonamide CA inhibitors.
- Cvijeti?, Ilija N.,Tan?, Muhammet,Jurani?, Ivan O.,Verbi?, Tatjana ?.,Supuran, Claudiu T.,Drakuli?, Branko J.
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p. 4649 - 4659
(2015/08/03)
-
- Development of the direct Suzuki-Miyaura cross-coupling of primary B-alkyl MIDA-boronates and aryl bromides
-
The development of a palladium-catalyzed sp3-sp2 Suzuki-Miyaura cross-coupling of B-alkyl-N-methyliminodiacetyl (B-alkyl MIDA) boronates and (hetero)aryl bromides is reported. This transformation is tolerant of a variety of functional groups (F, NO2, CN, Cl, COCH3, and CHO). B-Alkyl MIDA boronates allow an efficient cross-coupling reaction directed toward the synthesis of unsymmetrical methylene diaryls as well as alkylated arenes in good to excellent yields.
- St. Denis, Jeffrey D.,Scully, Conor C. G.,Lee, C. Frank,Yudin, Andrei K.
-
supporting information
p. 1338 - 1341
(2014/04/03)
-
- Reusable, highly active heterogeneous palladium catalyst by convenient self-encapsulation cross-linking polymerization for multiple carbon-carbon cross-coupling reactions at ppm to ppb palladium loadings
-
Designing reusable high-performance heterogeneous palladium (Pd) catalysts via convenient, economic synthesis is of great importance to the industrial applications of various carbon-carbon crosscoupling reactions. We demonstrate herein a convenient one-pot self-encapsulation synthesis of a heterogeneous Pd catalyst [Pd@PDEB, PDEB = poly(1,3-diethynylbenzene)] directly from commercially available, economic precursors. In the synthesis, the formation of the cross-linked polymer networks and Pd encapsulation are accomplished simultaneously, turning a homogeneous Pd polymerization catalyst into the heterogeneous cross-coupling catalyst. As a unique, practical heterogeneous catalyst, Pd@PDEB shows remarkably high activity, high reusability, and high versatility towards at least four types of cross-coupling reactions (Suzuki-Miyaura, Stille, allylic arylation, and Mizoroki-Heck reactions) with even difficult reactants (aryl chlorides and heteroaryl halides) under aerobic conditions with Pd loadings down to ppm or even ppb levels. Evidences from hot filtration and 3-phase tests demonstrate the heterogeneous nature of the catalyst with very low Pd leaching and negligible contributions of leached homogeneous Pd species towards the coupling reactions.
- Donga, Zhongmin,Yea, Zhibin
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p. 3401 - 3414
(2015/02/05)
-
- Regio-specific polyacetylenes synthesized from anionic polymerizations of template monomers
-
Substituted polyacetylenes with alkylphenyl side groups and head-to-head regioregularity were prepared through anionic living polymerization of template monomers and subsequent dehydrogenation process. The template monomers have the structure of 2, 3-disubstituted-1, 3-butadienes prepared by palladium-catalyzed Kumada coupling of the corresponding vinyl bromides. Anionic polymerizations of the template monomers produced narrow disperse substituted polybutadiene precursors with exclusive 1, 4-enchainment. The precursors were converted into soluble polyacetylene derivatives via two methods, e.g., bromination followed by elimination of HBr, and direct dehydrogenation by 2, 3-dichloro-5, 6-dicyano-1, 4-benzoquinone (DDQ), both resulting in dark colored products with significant red shift in UV spectra. The obtained head-to-head polyacetylene derivatives exhibited highly thermal stability, possibly due to trans-rich and/or head-to-head chain configurations. The microstructures of the poly(2, 3-dialkylphenyl butadiene) precursors were analyzed in detail using NMR spectroscopy with regard to the solvent effect during polymerization. Block copolymers containing substituted polyacetylene segments were prepared through sequential anionic polymerization of different monomers, followed by dehydrogenation transformation. The present synthesis may serve as a new strategy for tailoring molecular structures of polyacetylene-based polymers by virtue of anionic living polymerization techniques.
- Zhang, Yang,Li, Jia,Li, Xiaohong,He, Junpo
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p. 6260 - 6269
(2015/02/19)
-
- Water-stabilized three- and four-atom palladium clusters as highly active catalytic species in ligand-free C-C cross-coupling reactions
-
Elite cliques: Palladium clusters with three and four atoms were found to be the catalytically active species for ligand-free palladium-catalyzed C-C bond-forming reactions (see picture). These palladium cluster species could be stabilized in water and stored for long periods of time for use on demand with no loss of activity. High yields of products and turnover frequencies (TOFs) of up to 105 h-1 were observed. Copyright
- Leyva-Perez, Antonio,Oliver-Meseguer, Judit,Rubio-Marques, Paula,Corma, Avelino
-
supporting information
p. 11554 - 11559
(2013/11/06)
-
- Fluorous oxime palladacycle: A precatalyst for carbon-carbon coupling reactions in aqueous and organic medium
-
To facilitate precatalyst recovery and reuse, we have developed a fluorous, oxime-based palladacycle 1 and demonstrated that it is a very efficient and versatile precatalyst for a wide range of carbon-carbon bond formation reactions (Suzuki-Miyaura, Sonogashira, Stille, Heck, Glaser-type, and Kumada) in either aqueous or organic medium under microwave irradiation. Palladacycle 1 could be recovered through F-SPE in various coupling reactions with recovery ranging from 84 to 95% for the first cycle. Inductively coupled plasma optical emission spectrometry (ICP-OES) analyses of the Pd content in the crude product from each class of transformation indicated extremely low levels of leaching and the palladacycle could be reused four to five times without significant loss of activity.
- Susanto, Woen,Chu, Chi-Yuan,Ang, Wei Jie,Chou, Tzyy-Chao,Lo, Lee-Chiang,Lam, Yulin
-
experimental part
p. 2729 - 2742
(2012/05/21)
-
- Small molecule suppression of carbapenem resistance in ndm-1 producing klebsiella pneumoniae
-
The already considerable global public health threat of multidrug-resistant Gram-negative bacteria has become even more of a concern following the emergence of New Delhi metallo-β-lactamase (NDM-1) producing strains of Klebsiella pneumoniae and other Gram-negative bacteria. As an alternative approach to the traditional development of new bactericidal entities, we have identified a 2-aminoimidazole-derived small molecule that acts as an antibiotic adjuvant and is able to suppress resistance of a NDM-1 producing strain of K. pneumoniae to imipenem and meropenem, in addition to suppressing resistance of other β-lactam nonsusceptible K. pneumoniae strains. The small molecule is able to lower carbapenem minimum inhibitory concentrations by up to 16-fold, while exhibiting little bactericidal activity itself.
- Worthington, Roberta J.,Bunders, Cynthia A.,Reed, Catherine S.,Melander, Christian
-
supporting information; experimental part
p. 357 - 361
(2012/07/01)
-
- Coordination and catalytic properties of a semihomologous Dppf congener, 1-(diphenylphosphino)-1′-[(diphenylphosphino)methyl]ferrocene
-
Alcohol Ph2PfcCH2OH (2, fc = ferrocene-1,1′- diyl) reacts smoothly with Ph2PH and Me3SiCl/NaI in acetonitrile to give 1-(diphenylphosphino)-1′-[(diphenylphosphino)methyl] ferrocene (1), a new ferrocene diphosphine that fills the obvious gap left between the well-studied 1,1′-bis(diphenylphosphino)ferrocene (dppf) and its bis-spaced analogue, 1,1′-bis[(diphenylphosphino)methyl]ferrocene. The P-oxidized alcohols Ph2P(E)fcCH2OH (E = O, 3; S, 4) behave similarly, yielding the corresponding semichalcogenides Ph 2P(E)fcCH2PPh2 (E = O, 5; S, 6). Exhaustive oxidations of 1 with hydrogen peroxide or elemental sulfur produce Ph 2P(E)fcCH2P(E)Ph2 (E = O, 7; S, 8), while similar oxidations of 5 and 6 afford the unsymmetric bis-chalcogenides Ph 2P(O)fcCH2P(S)Ph2 (9) and Ph 2P(S)fcCH2P(O)Ph2 (10), respectively. Compounds 1 and 3-10 were characterized by spectral methods, and the crystal structures of 3 and 8-10 were determined by single-crystal X-ray diffraction analysis. Compound 1 reacts with group 10 metal dichloride precursors to give the respective chelate complexes [MCl2(1-κ2P,P′)] (11, M = Ni; 12, M = Pd; and 13, M = Pt). The Ni complex is paramagnetic and tetrahedral; the Pd and Pt complexes are expectedly square-planar and diamagnetic. Crystal structures of 11-13 reveal less acute ligand bite angles (P-M-P′) than those observed in the analogous dppf complexes, the difference being considerably larger for the Ni complex than in the less flexible square-planar complexes. Similarly to dppf and fc(CH 2PPh2)2, ligand 1 reacts with [(L NC)PdCl]2 (LNC = [2-(dimethylamino)methyl] phenyl) to give a diphosphine-bridged complex, [(μ-1){(LNC)PdCl} 2] (14), whereas the reaction with the mononuclear precursor [(L NC)Pd(MeCN)2]ClO4 yields a mixture of isomeric bis-chelates [(LNC)Pd(1-κ2P,P′)]ClO 4 (15a,b). Catalytic tests in Pd-catalyzed Suzuki-Miyaura cross-coupling and in Pd-catalyzed cyanation of aryl halides with K 4[Fe(CN)6]?3H2O suggest that introduction of one methylene spacer group into the structure of dppf influences catalytic performance only marginally.
- Stepnicka, Petr,Cisarova, Ivana,Schulz, Jiri
-
experimental part
p. 4393 - 4403
(2011/10/18)
-
- Direct synthesis of water-tolerant alkyl indium reagents and their application in palladium-catalyzed couplings with aryl halides
-
A direct result: Alkyl indium reagents are synthesized by the insertion of indium into alkyl halide mediated by CuCl. The synthetic utility of these reagents is demonstrated by their palladium-catalyzed coupling with aryl halides (see scheme). The reagents are compatible with various functional groups, and this makes the protocol generally useful in organic synthesis. DMA=N,N-dimethylacetamide, TBS=tert-butyldimethylsilyl.
- Shen, Zhi-Liang,Goh, Kelvin Kau Kiat,Yang, Yong-Sheng,Lai, Yin-Chang,Wong, Colin Hong An,Cheong, Hao-Lun,Loh, Teck-Peng
-
supporting information; experimental part
p. 511 - 514
(2011/03/17)
-
- Palladium-catalyzed cross-coupling reactions of organogold(I) reagents with organic electrophiles
-
The palladium-catalyzed cross-coupling reaction of organogold(I) reagents (alkyl, alkenyl, aryl, and alkynyl) with organic electrophiles, such as aryl and alkenyl halides, aryl triflates, benzyl bromide, and benzoyl chloride is reported. The reaction takes place, under palladium catalysis, at room temperature with short reaction times to give the corresponding cross-coupling products in high yields.
- Pena-Lopez, Miguel,Ayan-Varela, Miguel,Sarandeses, Luis A.,Perez Sestelo, Jose
-
supporting information; experimental part
p. 9905 - 9909
(2010/10/19)
-
- Cross-coupling reactions through the intramolecular activation of Alkyl(triorgano)silanes
-
(Figure Presented) Cross-Si-ing the Jordan: Cross-coupling reactions of 2-(2-hydroxyprop-2-yl)phenylsubstituted alkylsilanes with a variety of aryl halides proceed in the presence of palladium and copper catalysts. The use of K3PO4 base allows for highly chemoselective alkyl coupling with both primary and secondary alkyl groups (Alk).
- Nakao, Yoshiaki,Takeda, Masahide,Matsumoto, Takuya,Hiyama, Tamejiro
-
supporting information; scheme or table
p. 4447 - 4450
(2010/08/19)
-
- Air-stable secondary phosphine oxide or chloride (Pre)ligands for cross-couplings of unactivated alkyl chlorides
-
In situ generated and crystallographically well-defined, isolated palladium complexes derived from seven novel air-stable secondary phosphine oxides or chlorides enabled challenging Kumada-Corriu cross-couplings of unactivated alkyl chlorides bearing β-hy
- Ackermann, Lutz,Kapdi, Anant R.,Schulzke, Carola
-
supporting information; experimental part
p. 2298 - 2301
(2010/08/05)
-
- Remarkably effective phosphanes simply with a PPh2 moiety: Application to Pd-Catalysed cross-coupling reactions for tetra-ortho-substituted biaryl syntheses
-
Chemical equation presented Expanding the horizons of ArPPh2: New applications of triarylphosphane ligands are presented. The Pd-L1 and Pd-L2 complexes offer exceptionally high activity in Suzuki-Miyaura cross-couplings of aryl chlorides. The extremely congested synthesis of tetraortho-substituted biaryl compounds is achieved for the first time by simply using triarylphosphane ligands.
- So, Chau Ming,Chow, Wing Kin,Choy, Pui Ying,Lau, Chak Po,Kwong, Fuk Yee
-
supporting information; experimental part
p. 7996 - 8001
(2010/09/05)
-
- Aerobic ligand-free Suzuki coupling catalyzed by in situ-generated palladium nanoparticles in water
-
A simple and efficient procedure for Suzuki coupling of aryl bromides/iodides with aryl- and alkylboronic acids catalyzed by in situ-generated palladium(0) nanoparticles in water without any ligand in open air to produce a variety of functionalized biaryls and alkyl-aryls has been developed. The boronic acids act here as the reducing agent for the formation of Pd nanoparticles. The reactions are remarkably fast (5 min) and high yielding. The catalyst is recyclable up to three runs without loss of efficiency.
- Saha, Debasree,Chattopadhyay, Kalicharan,Ranu, Brindaban C.
-
scheme or table
p. 1003 - 1006
(2009/05/11)
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- Kaiser oxime resin-derived palladacycle: A recoverable polymeric precatalyst in Suzuki-Miyaura reactions in aqueous media
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Representative cross-coupling reactions of aryl bromides with different types of aryl-, alkyl, trivinylboroxine-pyridine complex, and alkenylboronic acids are performed using a polymer-bonded palladacycle derived from Kaiser oxime resin as precatalyst and
- Alacid, Emilio,Nájera, Carmen
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body text
p. 1658 - 1665
(2009/10/11)
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- Pd(PPh3)4-PEG 400 catalyzed protocol for the atom-efficient stille cross-coupling reaction of organotin with aryl bromides
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(Chemical Equation Presented) Aryl bromides (4 equiv) were coupled efficiently with organotin (1 equiv) in an atom-efficient way using the tetra(triphenylphosphine)palladium/polyethylene glycol 400 (Pd(PPh 3)4/PEG 400) catalytic syst
- Zhou, Wen-Jun,Wang, Ke-Hu,Wang, Jin-Xian
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supporting information; experimental part
p. 5599 - 5602
(2009/12/03)
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- A nonsymmetric pincer-catalyzed Suzuki-Miyaura arylation of benzyl halides and other nonactivated unusual coupling partners
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(Chemical Equation Presented) The catalytic activity of a PCN-type palladium pincer complex is evaluated in the construction of C(sp 2)-C(sp2) and C(sp2)-C(sp3) bonds by Suzuki-Miyaura cross-couplings employing nontypical substrates such as benzyl halides, α-haloenones, or alkylboronic acids as coupling partners. Most of the reported reactions are achieved in aqueous media, with all of the advantages implied.
- Ines, Blanca,Moreno, Isabel,SanMartin, Raul,Dominguez, Esther
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supporting information; experimental part
p. 8448 - 8451
(2009/04/11)
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- A new family of tunable indolylphosphine ligands by one-pot assembly and their applications in Suzuki-Miyaura coupling of aryl chlorides
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(Chemical Equation Presented) This study describes a new class of indolylphosphine ligands, which can be easily accessed by a simple one-pot assembly from commercially available indoles, acid chlorides, and chlorophosphines. A combination of these three starting materials provides a high diversification of the ligand structure. The application of this ligand array in palladium-catalyzed Suzuki-Miyaura coupling reaction of aryl chlorides with arylboronic acids is described. A catalyst loading down to 0.01 mol % of Pd can be achieved.
- Chau, Ming So,Chung, Chiu Yeung,Chak, Po Lau,Fuk, Yee Kwong
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p. 7803 - 7806
(2008/12/22)
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- Easily accessible and highly tunable Lndolyl phosphine ligands for suzuki-miyaura coupling of aryl chlorides
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This study describes a new class of easily accessible indolyl phosphine ligands, prepared via an efficient protocol involving Fischer indolization from readily available Phenylhydrazine and substituted acetophenones. This versatile ligand scaffold provides beneficial features, including high potential of steric and electronic tunability. The air-stable indolyl phosphines in combination with a palladium metal precursor provide highly effective catalysts for Suzuki-Miyaura coupling of unactivated aryl chlorides, and the catalyst loading down to 0.02 mol % can be achieved.
- So, Chau Ming,Lau, Chak Po,Kwong, Fuk Yee
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p. 2795 - 2798
(2008/02/05)
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- ESI-MS detection of proposed reaction intermediates in the air-promoted and ligand-modulated oxidative heck reaction
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Electrospray ionization mass spectrometry (ESI-MS) and subsequent MS/MS analyses were used to directly detect palladium-containing cationic reaction intermediates in a ligand controlled palladium(II)-catalyzed oxidative Heck arylation. All potential intermediates were observed as dmphen-ligated palladium(II) species, suggesting that the dmphen bidentate ligand is attached to the metal center during the entire catalytic cycle. The study supports previous mechanistic propositions and provides new information regarding the composition of aryl-containing Pd(II) complexes in an ongoing oxidative Heck reaction. In addition, sodium acetate was found to be a useful base alternative to previously used tertiary amines.
- Enquist, Per-Anders,Nilsson, Peter,Sjoeberg, Per,Larhed, Mats
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p. 8779 - 8786
(2007/10/03)
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- Tetraphosphine/palladium catalysed Suzuki cross-coupling reactions of aryl halides with alkylboronic acids
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Through the use of [PdCl(C3H5)]2/cis,cis, cis-1,2,3,4-tetrakis(diphenylphosphinomethyl)cyclopentane as a catalyst, a range of aryl bromides and chlorides undergoes Suzuki cross-coupling with alkylboronic acids in good yields. Several alkyl substituents such as ethyl, n-butyl, n-octyl, isobutyl or 2,2-dimethylpropyl on the alkylboronic acids have been successfully used. The functional group tolerance on the aryl halide is remarkable; substituents such as fluoro, methyl, methoxy, acetyl, formyl, benzoyl, nitro or nitrile are tolerated. Furthermore, this catalyst can be used at low loading, even for reactions of sterically hindered aryl bromides.
- Kondolff, Isabelle,Doucet, Henri,Santelli, Maurice
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p. 3813 - 3818
(2007/10/03)
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- An active ferrocenyl triarylphosphine for palladium-catalyzed Suzuki-Miyaura cross-coupling of aryl halides
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Pd-catalyzed Suzuki-Miyaura reaction of aryl chlorides was accomplished through the use of an active ferrocene-based triarylphosphine ligand. This air- and moisture-stable ligand was found to be effective for the cross-coupling of aryl halides at room temperature to 115 °C.
- Kwong, Fuk Yee,Chan, Kin Shing,Yeung, Chi Hung,Chan, Albert S. C.
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p. 2336 - 2337
(2007/10/03)
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- Suzuki-Miyaura and related cross-couplings in aqueous solvents catalyzed by di(2-pyridyl)methylamine-palladium dichloride complexes
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Di(2-pyridyl)methylamine-based palladium dichloride complexes 4 are versatile catalysts for different types of cross-coupling reactions in water or aqueous solvents under aerobic conditions. The Suzuki-Miyaura reaction of arylboronic acids can be performed with bromoarenes under water reflux using K2CO3 as base or at room temperature or 60°C in aqueous methanol using KOH as base. For aryl chlorides the corresponding cross-couplings with arylboronic acids can be carried out in refluxing water with K2CO3 as base and TBAB as additive to provide biaryls and heterobiaryls. Arylboronic acids react with benzylic chlorides and allylic substrates such as chlorides, acetates or carbonates also in refluxing water with K2CO3 as base or at room temperature in aqueous acetone and KOH as base, to give diarylmethanes and arylpropenes. Trimethylboroxine and alkylboronic acids are coupled with bromo- and chloroarenes under water at reflux with K2CO3 as base and TBAB as additive to furnish methyl- and butylarenes. These cross-couplings have also been performed in shorter times under microwave irradiation. Several important intermediates such as, 4′-methylbiphenyl-2-carbonitrile, 4-biphenylacetic acid, 3-(3-methylphenyl)benzoic acid, 4,5-diphenyl-2-methyl- 3(2H)pyridazinone and 2-(4′-fluorobenzyl)thiophene have been prepared under aqueous and aerobic conditions in good yields.
- Najera, Carmen,Gil-Molto, Juan,Karlstroem, Sofia
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p. 1798 - 1811
(2007/10/03)
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- Orthopalladated and -platinated bulky triarylphosphite complexes: Synthesis, reactivity and application as high-activity catalysts for Suzuki and Stille coupling reactions
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Bulky triarylphosphite ligands undergo facile orthometallation reactions with palladium and platinum precursors. The crystal structure of an example of the resultant palladacycles has been determined. The reactivity of some of the metallacycles with HCl, monodentate and bidentate phosphines and sodium diethyldithiocarbamate has been investigated, and the crystal structure of a diethyldithiocarbamate adduct of a palladacycle is presented. The palladacyclic complexes prove to be extremely active catalysts for the Suzuki coupling of aryl bromides with aryl boronic acids. They can also be used as catalysts for the coupling of alkylboronic acids. Meanwhile di- and trialkyl phosphine adducts of one of the pallada-cycles shows very high activity in the Suzuki coupling of aryl chlorides and can also be used to good effect for the Stille coupling of these substrates. The role of the phosphite ligand in the Suzuki coupling of aryl chlorides seems to be one of increasing catalyst longevity by stabilisation of the Pd0 resting state.
- Bedford, Robin B.,Hazelwood, Samantha L.,Limmert, Michael E.,Albisson, David A.,Draper, Sylvia M.,Scully, P. Noelle,Coles, Simon J.,Hursthouse, Michael B.
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p. 3216 - 3227
(2007/10/03)
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- Tetraorganoindates as Nucleophilic Coupling Partners in Pd-Catalyzed Cross-Coupling Reactions
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(Equation presented) In situ generated ate complex In situ-generated tetraorganoindate complexes from the reaction of 1 equiv of indium trichloride with 4 equiv of appropriate organometallics are efficient nucleophiles in Pd-catalyzed cross-coupling reactions. In this novel reaction tetraorganoindates containing methyl, 1°- and 2°-alkyl, vinyl, alkynyl, and aryl groups transfer the four organic groups to a variety of electrophiles with high atom efficiency.
- Lee, Phil Ho,Lee, Sung Wook,Seomoon, Dong
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p. 4963 - 4966
(2007/10/03)
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- Pd-catalyzed carbonylative cross-coupling reactions by triorganoindiums: Highly efficient transfer of organic groups attached to indium under atmospheric pressure
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(Matrix presented) A highly atom-efficient synthetic method of unsymmetrical ketones was developed by using trialkyl- and triarylindiums, which could be employed as effective cross-coupling partners in Pd-catalyzed carbonylative cross-coupling reactions with a variety of organic electrophiles. The present method produced unsymmetrical ketones and 1,4-diacylbenzenes in good yields with highly efficient transfer of almost all the organic groups attached to the indium under atmospheric pressure of CO gas in THF at 66°C.
- Lee, Phil Ho,Lee, Sung Wook,Lee, Kooyeon
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p. 1103 - 1106
(2007/10/03)
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- Cross-coupling reactions with boronic acids in water catalysed by oxime-derived palladacycles
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Palladacycles derived from phenone-oximes 1 are efficient precatalysts for the Suzuki-Miyaura coupling of arylboronic acids with aromatic and heteroaromatic bromides and chlorides under water reflux under aerobic conditions. Alternatively, the coupling can also be carried out at room temperature in methanol-water. Aryl bromides gave biaryls with TON up to 105 and TOF up to 7 × 104 h-1. Activated and deactivated aryl chlorides need the presence of TBAB for the couplings, showing slightly lower efficiency (TON up to 9000 and TOF up to 3850 h-1). C(sp2)-C(sp3) bonds can also be formed by cross-coupling reactions of trimethylboroxine and butylboronic acid with aromatic bromides and chlorides under water reflux and of benzylic and allylic chlorides or acetates with arylboronic acids in acetone-water at room temperature.
- Botella, Luis,Nájera, Carmen
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- Palladium-catalyzed cross-methylation of haloarenes possessing active hydrogen atoms by intramolecularly stabilized dimethylindium and dimethylaluminum reagents
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While the intramolecularly stabilized aluminum complex [(CH3)2AlOCH2CH2 N(CH3)2]2 (2a) reacts readily with 4-bromophenol to give methane and [(4-BrC6H4O)su
- Jaber, Nimer,Gelman, Dmitri,Schumann, Herbert,Dechert, Sebastian,Blum, Jochanan
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p. 1628 - 1632
(2007/10/03)
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- Scope and limitation of the nickel-catalyzed coupling reaction between lithium borates and mesylates
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Coupling reaction of aryl borates and mesylates derived from phenols and enols was studied. Mesylates with an electron-with-drawing group or ring were highly reactive at room temperature in the presence of NiCl2(PPh3)2 to furnish the coupling products in good yields.
- Kobayashi, Yuichi,William, Anthony D.,Mizojiri, Ryo
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- Suzuki-Miyaura cross-coupling of lithium n-alkylborates
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The palladium-catalyzed cross-coupling of lithium n-alkylborates, generated in situ via addition of sec-butyl lithium to boronate esters, proceeds in moderate to good yields with a wide variety of electrophiles.
- Zou, Gang,Falck
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p. 5817 - 5819
(2007/10/03)
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- Ag(I)-promoted Suzuki-Miyaura cross-couplings of n-alkylboronic acids
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Ag(I) salts significantly enhance palladium-catalyzed Suzuki-Miyaura cross-couplings of n-alkylboronic acids with a wide variety of aryl and alkenyl halides/triflates.
- Zou, Gang,Reddy, Y. Krishna,Falck
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p. 7213 - 7215
(2007/10/03)
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- Atom-efficient metal-catalyzed cross-coupling reaction of indium organometallics with organic electrophiles
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The novel metal-catalyzed cross-coupling reaction of indium organometallics with organic electrophiles is described. Triorganoindium compounds (R3In) containing alkyl, vinyl, aryl, and alkynyl groups are efficiently prepared from the correspond
- Perez,Sestelo,Sarandeses
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p. 4155 - 4160
(2007/10/03)
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- One-step cross-coupling reaction of functionalized alkyl iodides with aryl halides by the use of an electrochemical method
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Organozinc compounds of functionalized alkyl iodide carrying an alkoxycarbonyl, cyano or alkenyl group were prepared in high yields under mild conditions (0°C-r.t., 10min in DMF) by the reaction of iodides with an electrogenerated reactive zinc (EGZn). Cross-coupling of the organozinc compounds with various aryl halides in the presence of 5 mol% Pd(P(o- Tol)3)2Cl2 in THF gave the corresponding cross-coupled products in moderate to high yields. These cross-coupling reactions can be also achieved in one step and in one pot by the use of an electrochemical method utilizing a Pt cathode and Zn anode.
- Kurono, Nobuhito,Sugita, Kazuya,Takasugi, Shingo,Tokuda, Masao
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p. 6097 - 6108
(2007/10/03)
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