- Directed Zincation or Magnesiation of the 2-Pyridone and 2,7-Naphthyridone Scaffold Using TMP Bases
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A regioselective zincation of the 2-pyridone and 2,7-naphthyridone scaffolds has been developed. Zincations of the methoxyethoxymethyl (MEM)-protected compounds using TMP2Zn·2MgCl2·2LiCl (TMP = 2,2,6,6-tetramethylpiperidyl) followed
- Ziegler, Dorothée S.,Greiner, Robert,Lumpe, Henning,Kqiku, Laura,Karaghiosoff, Konstantin,Knochel, Paul
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- Enantiomerically Enriched α-Borylzinc Reagents by Nickel-Catalyzed Carbozincation of Vinylboronic Esters
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In this paper is described a synthesis of enantiomerically enriched, configurationally stable organozinc reagents by catalytic enantioselective carbozincation of a vinylboronic ester. This process furnishes enantiomerically enriched α-borylzinc intermediates that are shown to undergo stereospecific reactions, producing enantioenriched secondary boronic ester products. The properties of the intermediate α-borylzinc reagent are probed and the synthetic utility of the products is demonstrated by application to the synthesis of (-)-aphanorphine and (-)-enterolactone.
- Chen, Jingjia,Hu, Weipeng,Jin, Jing,Lovinger, Gabriel J.,Morken, James P.,Zhang, Chenlong
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supporting information
p. 14189 - 14195
(2021/09/11)
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- The Formation of P-C Bonds Utilizing Organozinc Reagents for the Synthesis of Aryl- A nd Heteroaryl-Dichlorophosphines
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Aryl- A nd heteroaryl-dichlorophosphines are mildly and selectively made in a one-pot synthesis in moderate to good yields starting from the respective aryl bromides or five-membered heterocycles, following lithiation with nBuLi, transmetalation with ZnCl
- Kirst, Christin,Tietze, Jonathan,Ebeling, Marian,Horndasch, Lukas,Karaghiosoff, Konstantin
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p. 17337 - 17343
(2021/11/18)
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- Ni-Catalyzed C(sp3)–O Arylation of α-Hydroxy Esters
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A Negishi cross-coupling of α-hydroxy ester derivatives and arylzinc reagents has been developed. This reaction tolerates both primary and secondary C(sp3)–O alcohol precursors and achieves efficient cross-coupling under Ni catalysis without the need for added external metal reductant, photocatalyst, or additives. The arylation of readily accessible C(sp3)–O electrophiles in this operationally simple, rapid, and mild reaction provides a complementary way of accessing desirable α-aryl ester products.
- Monteith, John J.,Rousseaux, Sophie A. L.
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supporting information
p. 9485 - 9489
(2021/12/09)
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- Asymmetric Synthesis of Alkylzincs by Rhodium-Catalyzed Enantioselective Arylative Cyclization of 1,6-Enynes with Arylzincs
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A chiral diene-rhodium complex was found to catalyze the reaction of 1,6-enynes with ArZnCl to give high yields of 2-(alkylidene)cyclopentylmethylzincs with high enantioselectivity (95–99 % ee). The enantioenriched alkylzincs were readily converted in a one-pot approach into a wide variety of functionalized products by taking advantage of their unique reactivity. The catalytic cylcle involves arylrhodation of alkyne, intramolecular alkenylrhodation of alkene, and transmetalation of the alkyl-rhodium intermediate into alkylzinc.
- Chen, Jiahua,Hayashi, Tamio
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supporting information
p. 18510 - 18514
(2020/08/21)
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- Rhodium-Catalyzed Arylzincation of Alkynes: Ligand Control of 1,4-Migration Selectivity
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The addition of arylzinc reagents ArZnCl 1 to alkynes 2 was found to be catalyzed by rhodium complexes in the presence of a catalytic amount of zinc chloride. The selectivity in giving 2-arylalkenylzinc species 3 or ortho-alkenylarylzinc species 4, the la
- Ming, Jialin,Hayashi, Tamio
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p. 6188 - 6192
(2018/10/02)
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- Nickel-catalyzed cross-coupling of β-carbonyl alkenyl pivalates with arylzinc chlorides
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The nickel-catalyzed cross-coupling reaction of β-carbonyl alkenyl pivalates with arylzinc reagents generates 3-aryl-substituted α,β-unsaturated carbonyl compounds via C-O bond cleavage. The reaction features mild reaction conditions, a wide scope of substrates, and good functional group tolerance.
- Pan, Wen-Jing,Wang, Zhong-Xia
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p. 1029 - 1036
(2018/02/19)
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- Synthesis of some ketones via nano-nickel oxide catalyzed acylation of arylzinc reagents; strategy involving the use of mixed (methyl)(aryl)zincs
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Nano-NiO catalyzed acylation of mixed (methyl)(aryl)zincs with aromatic acyl halides in THF at room temperature provides a new facile route for aryl–aroyl coupling. Among NiCl2 .L2 and NiCl2 .L (L = monodentate and bidentate phosphine ligand) catalysts, the lower catalyst loading of NiCl2 (dppf) may seem attractive; however, nano-NiO, being the lowest cost catalyst, is more favorable for aroylation of (methyl)(aryl)zincs. This procedure also provides a supplement to Cu and Pd catalyzed acylation of diorganozincs.
- Pekel, ?zgen ?MüR,Erdik, Ender,Kalkan, Melike
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p. 759 - 767
(2018/06/07)
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- Transition-Metal-Free Cross-Coupling of Aryl and Heteroaryl Thiols with Arylzinc Reagents
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Cross-coupling of (hetero)arylthiols with arylzinc reagents via C-S cleavage was performed under transition-metal-free conditions. The reaction displays a wide scope of substrates and high functional-group tolerance. Electron-rich and -deficient (hetero)arylthiols and arylzinc reagents can be employed in this transformation. Mg2+ and Li+ ions were demonstrated to facilitate the reaction.
- Yang, Bo,Wang, Zhong-Xia
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supporting information
p. 6220 - 6223
(2017/11/24)
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- Divergent Synthetic Access to E- and Z-Stereodefined All-Carbon-Substituted Olefin Scaffolds: Application to Parallel Synthesis of (E)- and (Z)-Tamoxifens
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A highly substrate-general synthesis of all-carbon-substituted E- and Z-stereodefined olefins is performed. The method comprises two sets of parallel and stereocomplementary preparations of (E)- and (Z)-α,β-unsaturated esters involving two robust and distinctive reactions: 1) stereocomplementary enol tosylations using readily available TsCl/diamine/(LiCl) base reagents, and 2) stereoretentive Negishi cross-coupling using the catalysts [Pd(dppe)Cl2] (for E) and [Pd(dppb)Cl2] (for Z). The present parallel approach is categorized as both type I (convergent approach: 16 examples, 56–87 % yield) and type II (divergent approach: 18 examples, 70–95 % yield). The obtained (E)- and (Z)-α,β-unsaturated ester scaffolds are successfully transformed into various E- and Z-stereodefined known and novel olefins (8×2 derivatization arrays). As a demonstration, application to the parallel synthesis of both (E)- and (Z)-tamoxifens, a representative motif of all-carbon-substituted olefins, is accomplished in a total of eight steps with an overall yield of 58 % (average 93 %) and 57 % (average 93 %), respectively.
- Ashida, Yuichiro,Honda, Atsushi,Sato, Yuka,Nakatsuji, Hidefumi,Tanabe, Yoo
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- Dehydration-type Ti-Claisen Condensation (Carbonhomologation) of α-Heteroatom-substituted Acetates with Alkyl Formates: Utilization as (Z)-Stereodefined Cross-coupling Partners and Application to Concise Synthesis of Strobilurin A
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TiCl4?Et3N or ?Bu3N reagent conducted a highly (Z)-stereoselective carbon homologation (dehydration type Ti-Claisen condensation) of alkyl α-heteroatom (halo and sulfonyloxy)-substituted acetates (XCH2CO2R) with alkyl formates (HCO2R) to afford various alkyl β-alkoxy-α-halo or sulfonyloxy-substituted acrylates (24 examples; 51%–91% yield). Stereoretentive Suzuki-Miyaura, Negishi, and Sonogashira cross-couplings using the obtained methyl β-methoxy-α-halo or sulfonyloxy-substituted acrylates proceeded smoothly to produce a variety of β-alkoxy-α-substituted acrylates in moderate to high yield (35 examples; 29%–99% yield). As a successful application, a 3-step straightforward synthesis of strobilurin A was performed utilizing the present reaction sequence (dehydration type Ti-Claisen condensation and Suzuki-Miyaura cross-coupling), wherein the geometry of the three consecutive olefins (2E,3Z,5E) was completely maintained. (Figure presented.).
- Nakatsuji, Hidefumi,Kamada, Risa,Kitaguchi, Hideya,Tanabe, Yoo
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p. 3865 - 3879
(2017/11/15)
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- Self-Assembled Multilayer-Stabilized Nickel Nanoparticle Catalyst for Ligand-Free Cross-Coupling Reactions: in situ Metal Nanoparticle and Nanospace Simultaneous Organization
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We have developed a conceptually and methodologically novel self-assembled multilayer nickel nanoparticle (NP) catalyst – sulfur-modified gold-supported Ni NPs (SANi) – for organic synthesis. The SANi catalyst was easily prepared through a three-step procedure involving simultaneous in situ metal NP and nanospace organization. This unique method does not require any conventional preformed template for immobilizing and stabilizing NPs. SANi catalyzes carbon-carbon bond-forming cross-coupling, Kumada coupling, and Negishi coupling reactions under ligand-free conditions and can be used repeatedly for these reactions. Physical analysis of SANi showed that the active species in these reactions are self-assembled multilayer zerovalent Ni NPs with a size of ~3 nm. (Figure presented.).
- Hoshiya, Naoyuki,Fujiki, Katsumasa,Taniguchi, Takahisa,Honma, Tetsuo,Tamenori, Yusuke,Xiao, Mincen,Saito, Nozomi,Yokoyama, Mami,Ishii, Akira,Fujioka, Hiromichi,Shuto, Satoshi,Sato, Yoshihiro,Arisawa, Mitsuhiro
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p. 2449 - 2459
(2016/08/16)
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- Rh-Catalyzed Conjugate Addition of Arylzinc Chlorides to Thiochromones: A Highly Enantioselective Pathway for Accessing Chiral Thioflavanones
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A highly efficient asymmetric synthesis of chiral thioflavanones is developed via conjugate addition of arylzinc reagents to thiochromones using Rh(COD)Cl2/(R)-3,4,5-MeO-MeOBIPHEP catalyst. This method overcomes catalyst poisoning and substrate inertness and affords a series of chiral thioflavanones (2-arylthiochroman-4-ones) in good yields (up to 91% yield) with excellent ee values (up to 97% ee). The established asymmetric synthesis paves the way for further pharmaceutical studies.
- Meng, Ling,Jin, Ming Yu,Wang, Jun
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supporting information
p. 4986 - 4989
(2016/10/14)
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- BORON-CONTAINING COMPOUND
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PROBLEM TO BE SOLVED: To provide a boron-containing compound suitable as an organic electronic device material such as an organic EL element material and an n-type semiconductor. SOLUTION: The present invention provides a boron-containing compound having a specific structure. SELECTED DRAWING: None COPYRIGHT: (C)2016,JPOandINPIT
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Paragraph 0088; 0092
(2018/10/31)
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- Pincer-Nickel-Catalyzed Cross-Coupling of Aryl Sulfamates with Arylzinc Chlorides
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The nickel N,N,N-pincer complex 2 was demonstrated to effectively catalyze the cross-coupling of aryl sulfamates with arylzinc chlorides under mild conditions. The reaction is suitable for a wide range of substrates, and tolerates various functional groups. A nickel N,N,N-pincer complex effectively catalyzes the cross-coupling of aryl sulfamates with arylzinc chlorides under mild conditions. The reaction is suitable for a wide range of substrates, and tolerates various functional groups.
- Tao, Jian-Long,Wang, Zhong-Xia
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p. 6534 - 6540
(2015/10/19)
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- Ligand-Free Copper-Catalyzed Negishi Coupling of Alkyl-, Aryl-, and Alkynylzinc Reagents with Heteroaryl Iodides
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Reported herein is an unprecedented ligand-free copper-catalyzed cross-coupling of alkyl-, aryl-, and alkynylzinc reagents with heteroaryl iodides. The reaction proceeds at room temperature for the coupling of primary, secondary, and tertiary alkylzinc reagents with heteroaryl iodides without rearrangement. An elevated temperature (100 C) is required for aryl-heteroaryl and alkynyl-heteroaryl couplings.
- Thapa, Surendra,Kafle, Arjun,Gurung, Santosh K.,Montoya, Adam,Riedel, Patrick,Giri, Ramesh
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supporting information
p. 8236 - 8240
(2015/07/07)
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- Pincer-Nickel-Catalyzed Allyl-Aryl Coupling between Allyl Methyl Ethers and Arylzinc Chlorides
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The P,N,N-pincer nickel complex [Ni(Cl){N(2-Ph2PC6H4)(2′-Me2NC6H4)}]-catalyzed allyl-aryl coupling was studied. The reaction of allyl methyl ethers, including (1-methoxyallyl)arenes and (3-methoxyprop-1-en-1-yl)arenes, with arylzinc chlorides afforded linear (E)-alkenes in high yields, whereas the reaction of (E)-1-methoxytridec-2-ene with p-Me2NC6H4ZnCl generated a mixture of linear and branched alkenes.
- Tao, Jian-Long,Yang, Bo,Wang, Zhong-Xia
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p. 12627 - 12634
(2016/01/09)
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- Which one is faster? A kinetic investigation of Pd and Ni catalyzed Negishi-type oxidative coupling reactions
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The difference between Pd and Ni has been investigated based on the Negishi-type oxidative coupling reactions in which reductive elimination was proved to be the rate determining step. Although DFT calculations illustrate that the Pd catalyzed reaction should be faster than the Ni catalyzed reaction under these conditions, kinetic experiments indicate that the reaction rate of Pd and Ni is dependent on the concentration of the catalyst precursor. The Pd catalyzed reaction is faster than the Ni catalyzed reaction only when the precursor concentration is as low as 1 × 10-7 M.
- Xin, Jie,Zhang, Guanghui,Deng, Yi,Zhang, Heng,Lei, Aiwen
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supporting information
p. 19777 - 19781
(2015/12/17)
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- Stereoconvergent negishi arylations of racemic secondary alkyl electrophiles: Differentiating between a CF3 and an alkyl group
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In this report, we establish that a readily available nickel/bis(oxazoline) catalyst accomplishes a wide array of enantioconvergent cross-couplings of arylzinc reagents with CF3-substituted racemic secondary alkyl halides, a process that necessitates that the chiral catalyst be able to effectively distinguish between a CF3 and an alkyl group in order to provide good ee. We further demonstrate that this method can be applied without modification to the catalytic asymmetric synthesis of other families of fluorinated organic compounds.
- Liang, Yufan,Fu, Gregory C.
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supporting information
p. 9523 - 9526
(2015/08/18)
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- Reactivity of mixed organozinc and mixed organocopper reagents: 11. Nickel-catalyzed atom-economic aryl-allyl coupling of mixed (n-alkyl)(aryl)zincs
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Group selectivity in the allylation of mixed (n-butyl)(phenyl)zinc reagent can be controlled by changing reaction parameters. CuCN-catalyzed allylation in tetrahydrofuran (THF)-hexamethylphosphoric triamide is n-butyl selective and also γ-selective in the presence of MgCl2, whereas CuI-catalyzed allylation in THF in the presence of n-Bu3P takes place with a n-butyl transfer:phenyl transfer ratio of 23:77 and an α:γ transfer ratio of phenyl of 76:24. NiCl2(Ph3P) 2-catalyzed allylation in the presence of LiCl is phenyl selective with an α:γ ratio of 65:35. The reaction of methyl- or n-butyl(aryl)zinc reagents with an allylic electrophile in THF at room temperature in the presence of NiCl2(Ph3P)2 catalyst and LiCl as an additive provides an atom-economic alternative to aryl-allyl coupling using diarylzincs. Copyright
- Kalkan, Melike
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p. 725 - 732
(2014/11/08)
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- Mono- and dinuclear pincer nickel catalyzed activation and transformation of C-Cl, C-N, and C-O bonds
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Condensation of 2-NH2C6H4P(Et)Ph (2) with pyrrole-2-carboxaldehyde generated 2-(C4H4N-2′-CH - N)C6H4P(Et)Ph (3). Treatment of 3 with NaH and followed by (DME)NiX2 (X = Cl, Br) afforded mononuclear pincer nickel complexes [Ni{2-(C4H3N-2′-CH - N)C6H4P(Et)Ph}X] (4a, X = Cl; 4b, X = Br). Reaction of [2-NH2C6H4P(Ph)]2(CH2)n (5a, n = 3; 5b, n = 4) with pyrrole-2-carboxaldehyde or 5-tert-butyl-1H-pyrrole-2-carbaldehyde formed [2-(C4H4N-2′-CH - N)C6H4P(Ph)]2(CH2)n (6a, n = 3; 6b, n = 4) and [2-(5′-tBuC4H3N-2′-CH - N)C6H4P(Ph)]2(CH2)4 (6c). Respective treatment of 6a-c with NaH followed by (DME)NiX2 (X = Cl, Br) gave the dinuclear nickel complexes [Ni{2-(5′-RC4H2N-2′-CH - N)C6H4P(Ph)}X]2(CH2)n (7a, R = H, X = Cl, n = 3; 7b, R = H, X = Cl, n = 4; 7c, R = H, X = Br, n = 4; 7d, R = tBu, X = Cl, n = 4). Catalysis of the complexes for the activation and transformation of C-Cl, C-N, and C-O bonds was evaluated. Complex 7c exhibited excellent catalytic activity in the cross-coupling of aryl chlorides or aryltrimethylammonium iodides with arylzinc reagents as well as of aryl sulfamates with aryl Grignard reagents. The dinuclear nickel complexes 7b-d showed higher catalytic activity than the mononuclear complexes in each type of reaction.
- Yang, Xia,Wang, Zhong-Xia
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p. 5863 - 5873
(2015/01/09)
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- Quantitative kinetic investigation on transmetalation of ArZnX in a Pd-catalysed oxidative coupling
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Transmetalation is the rate-limiting step. [R-Pd-Ar] was suggested to be the resting species from the kinetic studies. Quantitative measurement of the transmetalation of ArZnCl with [R-Pd-Ar] from a live Pd-catalysed oxidative coupling reaction was conducted and the corresponding activation enthalpy was determined as 12.3 kcal mol-1. The Royal Society of Chemistry 2013.
- Li, Jing,Jin, Liqun,Liu, Chao,Lei, Aiwen
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p. 9615 - 9617
(2013/10/08)
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