- Nickel-catalysed decarbonylative borylation of aroyl fluorides
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The first Ni(cod)2/PPh3 catalyst system has been established for decarbonylative borylation of aroyl fluorides with bis(pinacolato)diboron. A wide range of functional groups in the substrates were well tolerated. The ease of access of the starting aroyl fluorides indicates that these results might become an alternative to the existing decarbonylation events.
- Wang, Zhenhua,Wang, Xiu,Nishihara, Yasushi
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- Cross-Coupling through Ag(I)/Ag(III) Redox Manifold
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In ample variety of transformations, the presence of silver as an additive or co-catalyst is believed to be innocuous for the efficiency of the operating metal catalyst. Even though Ag additives are required often as coupling partners, oxidants or halide scavengers, its role as a catalytically competent species is widely neglected in cross-coupling reactions. Most likely, this is due to the erroneously assumed incapacity of Ag to undergo 2e? redox steps. Definite proof is herein provided for the required elementary steps to accomplish the oxidative trifluoromethylation of arenes through AgI/AgIII redox catalysis (i. e. CEL coupling), namely: i) easy AgI/AgIII 2e? oxidation mediated by air; ii) bpy/phen ligation to AgIII; iii) boron-to-AgIII aryl transfer; and iv) ulterior reductive elimination of benzotrifluorides from an [aryl-AgIII-CF3] fragment. More precisely, an ultimate entry and full characterization of organosilver(III) compounds [K]+[AgIII(CF3)4]? (K-1), [(bpy)AgIII(CF3)3] (2) and [(phen)AgIII(CF3)3] (3), is described. The utility of 3 in cross-coupling has been showcased unambiguously, and a large variety of arylboron compounds was trifluoromethylated via [AgIII(aryl)(CF3)3]? intermediates. This work breaks with old stereotypes and misconceptions regarding the inability of Ag to undergo cross-coupling by itself.
- Demonti, Luca,Mézailles, Nicolas,Nebra, Noel,Saffon-Merceron, Nathalie
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supporting information
p. 15396 - 15405
(2021/10/12)
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- Radical Metal-Free Borylation of Aryl Iodides
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A simple metal-free borylation of aryl iodides mediated by a fluoride sp 2 -sp 3 diboron adduct is described. The reaction conditions are compatible with various functional groups. Electronic effects of substituents do not affect the borylation while steric hindrance does. The reaction proceeds via a radical mechanism in which pyridine serves to stabilize the boryl radicals, generated in situ.
- Pinet, Sandra,Liautard, Virginie,Debiais, Mégane,Pucheault, Mathieu
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p. 4759 - 4768
(2017/10/03)
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- Rhodium-Catalyzed Decarbonylative Borylation of Aromatic Thioesters for Facile Diversification of Aromatic Carboxylic Acids
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Transformation of aromatic thioesters into arylboronic esters was achieved efficiently using a rhodium catalyst. The broad functional-group tolerance and mild conditions of the method have allowed for the two-step decarboxylative borylation of a wide range of aromatic carboxylic acids, including commercially available drugs.
- Ochiai, Hidenori,Uetake, Yuta,Niwa, Takashi,Hosoya, Takamitsu
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p. 2482 - 2486
(2017/02/23)
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- The method for producing the phenyl boronic acid ester
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PROBLEM TO BE SOLVED: To provide a method for producing phenylboronic acid esters in good yield from diborons and aryl halides by using a nickel catalyst and a base. SOLUTION: In the method for producing phenylboronic acid esters represented by general formula (3), wherein A is an ethylene group or the like which may be substituted by a methyl group, R1is a fluorine atom or the like, and m is an integer of 0-5; diborons and a chlorobenzene derivative are reacted with each other by using a trimethylphosphine coordinated nickel catalyst and alkoxides. COPYRIGHT: (C)2013,JPOandINPIT
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Paragraph 0097; 0098
(2018/09/26)
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- Syntheses of (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)arenes through Pd-catalyzed borylation of arylbromides with the successive use of 2,2′-bis(1,3,2-benzodioxaborole) and pinacol
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Syntheses of (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)arenes through the Pd-catalyzed borylation of arylbromides with the successive use of 2,2′-bis(1,3,2-benzodioxaborole) and pinacol were investigated. PdCl 2(dppf) and AcOK in EtOH or DMSO successfully provided (4,4,5,5-tetramethyl-1,3,2-dioxaborolan-2-yl)arenes. In particular, this method was more effective in the borylation of arylbromides bearing sulfonyl groups than the conventional Pd-catalyzed borylation using pinacolborane or bis(pinacolato)diboron.
- Takagi, Jun,Yamakawa, Tetsu
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p. 166 - 169
(2013/02/21)
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- NiCl2(PMe3)2-catalyzed borylation of aryl chlorides
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The cross-coupling of aryl chlorides and bis(pinacolato)diboron was achieved using NiCl2(PMe3)2 catalyst in the presence of metal 2,2,2-trifluoroethoxide. The catalyst smoothly provided the desired products regardless of a variety of functional groups and substituted positions.
- Yamamoto, Tetsuya,Morita, Tomoyuki,Takagi, Jun,Yamakawa, Tetsu
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supporting information; experimental part
p. 5766 - 5769
(2012/01/06)
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- Noncryogenic preparation of functionalized arylboronic esters through a magnesium-iodine exchange with in situ quench
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Various functionalized aryl boronic esters derived from hexylene glycol and pinacol were prepared in excellent yields according to a simple, safe procedure. The metal-halogen exchange reaction between iPrMgCl? LiCl and aryl iodides is performed
- Demory, Emilien,Blandin, Veronique,Einhorn, Jacques,Chavant, Pierre Y.
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experimental part
p. 710 - 716
(2012/10/23)
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- Mild iridium-catalyzed borylation of arenes. High turnover numbers, room temperature reactions, and isolation of a potential intermediate
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The borylation of arenes leads to the formation of synthetically versatile products from unactivated arene reagents. We report that Ir(I) precursors in conjunction with bipyridine ligands catalyze in high yields the borylation of arenes under mild conditions. These reactions encompase arenes bearing both electron-withdrawing and electron-donating substituents. The temperatures required for the transformation are much lower than those previously reported for direct arene borylation. The combination of [Ir(COE)2Cl]2 and (4,4-di-t-butyl)bipyridine even allows for reaction at room temperature. The same catalyst system at 100 °C provides remarkably high turnover numbers for a hydrocarbon functionalization process. Mechanistic studies show that the reactions involve uncommon, Ir(II) tris-boryl complexes. An example of this type of complex ligated by di-t-butylbipyridine was isolated and structurally characterized. It reacted rapidly at room temperature to produce aryl boronate esters in high yields. Copyright
- Ishiyama, Tatsuo,Takagi, Jun,Ishida, Kousaku,Miyaura, Norio,Anastasi, Natia R.,Hartwig, John F.
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p. 390 - 391
(2007/10/03)
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