- Late-Stage Aromatic C-H Oxygenation
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Synthetic methods for oxidative aromatic C-O bond formation are sparse, despite their demand in metabolite synthesis for drug discovery and development. We report a novel methodology for late-stage C-O bond formation of arenes. The reaction proceeds with excellent functional group tolerance even for highly functionalized substrates. The resulting aryl mesylates provide access to potential human metabolites of pharmaceuticals, and may be used directly to install a C-F bond to block metabolic hotspots. A charge-transfer interaction between the reagent bis(methanesulfonyl) peroxide and the substrate arenes may be relevant for the chemoselective functionalization of arenes over other functional groups.
- B?rgel, Jonas,Tanwar, Lalita,Berger, Florian,Ritter, Tobias
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supporting information
p. 16026 - 16031
(2018/12/13)
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- Cyanation of unactivated aryl chlorides and aryl mesylates catalyzed by palladium and hemilabile MOP-type ligands
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Palladium-catalyzed cyanation of aryl halides and pseudo halides with potassium hexacyanoferrate is described employing the hemilabile, bulky, and electron-rich MOP-type ligands. When the mixture of t-BuOH and H2O was used as the solvent and K2CO3 as the base, the MOP-type ligands showed high efficiency for the palladium-catalyzed cyanation. The effect of ligand structure was studied in detail, and 2-di-tert-butylphosphino-2′-isopropoxy-1,1′-binaphthyl was the more effective for the cyanation. The catalyst system allows the cyanation of unactivated aryl chlorides, and even aryl mesylates to occur in good yields. Furthermore, the reactivity of different arylated reagents in the catalytic system was found to be: ArBr > ArCl >> ArOMs > ArOSO2Im > ArOSO2NMe2.
- Tu, Yahui,Zhang, Yi,Xu, Sheng,Zhang, Zhaoguo,Xie, Xiaomin
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supporting information
p. 2938 - 2942
(2015/01/16)
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- Nickel catalyzed cross-coupling of aryl C-O based electrophiles with aryl neopentylglycolboronates
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The efficiency of mesylates, sulfamates, esters, carbonates, carbamates, and methyl ethers as C-O-based electrophiles attached to the 1- or 2-position of naphthalene and to activated and nonactivated phenyl substrates was compared for the first time in Ni-catalyzed cross-coupling with phenyl neopentylglycolboronates containing electron-rich and electron-deficient substituents in their para-position. These experiments were performed in the presence of four different Ni(II)- and Ni(0)-based catalysts. Ni(II)-based catalysts mediate the cross-coupling of most 2-naphthyl C-O electrophiles with both arylboronic acids and with neopentylglycolboronates when K 3PO4 is used as base. The same catalysts are not efficient when CsF is used as base. However, Ni(0)-based catalysts exhibit selective efficiency, and when reactive, their efficiency is higher than that of Ni(II)-based catalysts in the presence of both K3PO4 and CsF. These results provide both reaction conditions for the cross-coupling, and for the elaboration of orthogonal cross-coupling methodologies of various C-O based electrophiles with aryl neopentylglycolboronates. With the exception of mesylates and sulfamates the efficiency of all other 2-naphthyl C-O electrophiles was lower in cross-coupling with aryl neopentylglycolboronates than with arylboronic acids
- Leowanawat, Pawaret,Zhang, Na,Percec, Virgil
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experimental part
p. 1018 - 1025
(2012/03/22)
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- Neopentylglycolborylation of aryl mesylates and tosylates catalyzed by Ni-based mixed-ligand systems activated with Zn
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(Chemical Presented) The mixed-ligand system NiCl2(dppp)/dppf is shown to be an effective catalyst for the neopentylglycolborylation of ortho-, meta-, and para-substituted electron-rich and electrondeficient aryl mesylates and tosylates. The ad
- Wilson, Daniela A.,Wilson, Christopher J.,Moldoveanu, Costel,Resmerita, Ana-Maria,Corcoran, Patrick,Hoang, Lisa M.,Rosen, Brad M.,Percec, Virgil
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supporting information; experimental part
p. 1800 - 1801
(2010/04/24)
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- 2 -SUBSTITUTED- 3 -PHENYLPROPIONIC ACID DERIVATIVES AND THEIR USE IN THE TREATMENT OF INFLAMMATORY BOWEL DISEASE
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The present invention relates to 2-(substituted sulphur, sulphone or sulphoxide)-3-(substituted phenyl) propionic acid derivatives, 2-(substituted oxygen)-3-(substituted phenyl) propionic acid derivatives, benzoic acid derivatives, and derivatives of 2-methyl-2-(phenoxy or phenylthio)propanoic acid and 2-(methylor ethyl)-2-(phenoxy or phenylthio)butanoic acid, to processes for preparing such compounds, to their use in the treatment of inflammatory conditions, and to pharmaceutical compositions containing them.
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Page/Page column 55-56; 65
(2008/12/08)
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- A general palladium-catalyzed Suzuki-Miyaura coupling of aryl mesylates
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(Chemical Equation Presented) Catalyze this! The first palladium-catalyzed Suzuki-Miyaura coupling of unactivated aryl mesylates is reported, with not only arylboronic acids, but also other organoboron nucleophiles (see picture; Z=B(OH)2, BF3K, BPin). The reaction conditions are compatible with various common functional groups (R1=alkyl, OMe, CHO, CO, CN, CO2R′, heteroaryl).
- So, Chau Ming,Lau, Chak Po,Kwong, Fuk Yee
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supporting information; experimental part
p. 8059 - 8063
(2009/04/13)
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- Mechanistic study of a Pd/C-catalyzed reduction of aryl sulfonates using the Mg-MeOH-NH4OAc system
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A method for the deoxygenation of phenolic hydroxy groups via aryl triflates or mesylates has been established by using a combination of Pd/ C-Mg-MeOH. The addition of NH4OAc to the system markedly accelerated the reaction rate and expanded the scope of the reaction. Mechanistic studies suggested that a single-electron transfer process from the Pd0 center to the benzene ring is involved in the reduction of aryl sulfonates and that NH4OAc works as a solubilization re agent of the Mg salt and as an accelerator of the electron transfer, thus enhancing the reaction process. Our method was also applicable to the regioselective deuteration of benzene derivatives with CH3OD as the solvent and deuterium source: the original hydroxy group could be efficiently replaced with a deuterium atom.
- Mori, Akinori,Mizusaki, Tomoteru,Ikawa, Takashi,Maegawa, Tomohiro,Monguchi, Yasunari,Sajiki, Hironao
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p. 1432 - 1441
(2008/02/04)
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- Palladium on carbon-diethylamine-mediated hydrodeoxygenation of phenol derivatives under mild conditions
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We have found that phenolic hydroxyl groups were readily deoxygenated via aryl sulfonate under the Pd/C-catalyzed hydrogenation conditions in the presence of diethylamine and the method could also be applicable to the hydrodeoxygenation of morphine to afford 3-deoxy-7,8-dihydromorphine. Diethylamine is not only a scavenger of the corresponding methanesulfonic acid derivative, which is produced during the reaction progress, but also a strong promoter of the Pd/C-catalyzed reduction of aryl sulfonates. This catalyst system could provide a general method for the deoxygenation of various phenol derivatives because of its mild reaction conditions, ease of handling, and no need of particular apparatus.
- Mori, Akinori,Mizusaki, Tomoteru,Ikawa, Takashi,Maegawa, Tomohiro,Monguchi, Yasunari,Sajiki, Hironao
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p. 1270 - 1280
(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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- Aryl Mesylates in Metal-Catalyzed Homocoupling and Cross-Coupling Reactions. 1. Functional Symmetrical Biaryls from Phenols via Nickel-Catalyzed Homocoupling of Their Mesylates
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Aryl sulfonates including mesylate derived from phenols are converted in high yields to biaryls by homocoupling in the presence of catalytic amounts of zero-valent nickel catalysts generated in situ.This reaction provides the most convenient method for the synthesis of many functional symmetrical biaryls and was applied to the preparation of 2,2'-, 3,3'-, and 4,4'-disubstituted biphenyls and other biaryls.The influence of the electronic and steric effects of substituents attached in the ortho, meta, and para positions of aryl sulfonates and the nature of the sulfonate leaving group on the yield of homocoupled product as well as their influence on the extent of various side reactions were investigated.In addition, the influence of the effects of the polarity and dryness of solvent, halide ion source and concentration, and ratio of catalyst and ligand to aryl sulfonate are discussed.
- Percec, Virgil,Bae, Jin-Young,Zhao, Mingyang,Hill, Dale H.
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p. 176 - 185
(2007/10/02)
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