- Nickel-catalyzed C-O bond reduction of aryl and benzyl 2-pyridyl ethers
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The reduction of aryl and benzyl 2-pyridyl ethers with sodium isopropoxide was carried out via nickel-catalyzed C-OPy bond cleavage, giving reductive products in reasonable to excellent yields. This method allowed the 2-pyridyloxy group to be directly rem
- Li, Jing,Wang, Zhong-Xia
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- Nickel-Catalyzed Reaction of Aryl 2-Pyridyl Ethers with Silylzinc Chlorides: Silylation of Aryl 2-Pyridyl Ethers via Cleavage of the Carbon?Oxygen Bond
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Ni-catalyzed C?O(Py) bond activation and silylation of aryl 2-pyridyl ethers with silylzinc chlorides were carried out. This protocol allowed the 2-pyridyloxy group to be substituted by a silyl group with short reaction times, mild reaction conditions, and good compatibility of functional groups. (Figure presented.).
- Kong, Ying-Ying,Wang, Zhong-Xia
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p. 5440 - 5448
(2019/11/16)
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- Nickel-Catalyzed Amination of Aryl 2-Pyridyl Ethers via Cleavage of the Carbon-Oxygen Bond
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Reaction of aryl 2-pyridyl ethers with amines was carried out via Ni-catalyzed C-OPy bond cleavage, giving aniline derivatives in reasonable to excellent yields. Both electron-rich and electron-poor aryl 2-pyridyl ethers and a wide range of amines can be used in the transformation. The method provides a conversion way for the 2-pyridyloxy directing group in the C-H bond functionalization reactions.
- Li, Jing,Wang, Zhong-Xia
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p. 3723 - 3726
(2017/07/26)
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- Synthesis of 2 - fluoro phenol compounds
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The present invention provides a method for synthetizing a 2-fluoro phenol compound shown in a formula IV. The phenol compound shown in the formula I is prepared into a 2-pyridine oxygroup arene compound shown in a formula II through an Ullmann reaction, the 2-pyridine oxygroup arene compound shown in the formula II is mixed with a palladium catalyst, a fluorinating reagent, an additive and an organic solvent, the mixture is stirred under the temperature of 30-160 DEG C to perform a fluorination reaction to obtain an ortho-position fluoridated 2-pyridine oxygroup arene compound shown in a formula III, and the ortho-position fluoridated 2-pyridine oxygroup arene compound shown in the formula III is prepared into the 2-fluoro phenol compound shown in the formula IV through the action of alkali. The method provided by the present invention has the advantages of mild reaction conditions, simplicity in operations, good substrate adaptability, high fluorination selectivity and the like. The 2-fluoro phenol compound is shown in the figure below.
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Paragraph 0091; 0093
(2017/04/21)
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- Rhodium-catalyzed borylation of aryl 2-pyridyl ethers through cleavage of the carbon-oxygen bond: Borylative removal of the directing group
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The rhodium-catalyzed reaction of aryl 2-pyridyl ethers with a diboron reagent results in the formation of arylboronic acid derivatives via activation of the C(aryl)-O bonds. The straightforward synthesis of 1,2-disubstituted arenes was enabled through catalytic ortho C-H bond functionalization directed by the 2-pyridyloxy group followed by substitution of this group with a boryl group. Several control experiments revealed that the presence of a sp2 nitrogen atom at the 2-position of the substrate and the use of a boron-based reagent were crucial for the activation of the relatively inert C(aryl)-O bond of aryl 2-pyridyl ethers.
- Kinuta, Hirotaka,Tobisu, Mamoru,Chatani, Naoto
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supporting information
p. 1593 - 1600
(2015/03/05)
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- C-H functionalization of phenols using combined ruthenium and photoredox catalysis: In situ generation of the oxidant
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A combination of ruthenium and photoredox catalysis allowed the ortho olefination of phenols. Using visible light, the direct C-H functionalization of o-(2-pyridyl) phenols occurred, and diverse phenol ethers were obtained in good yields. The regeneration of the ruthenium catalyst was accomplished by a photoredox-catalyzed oxidative process.
- Fabry, David C.,Ronge, Meria A.,Zoller, Jochen,Rueping, Magnus
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supporting information
p. 2801 - 2805
(2015/03/04)
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- Palladium(II)-catalyzed ortho arylation of 2-phenoxypyridines with potassium aryltrifluoroborates via C-H functionalization
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An efficient synthesis of ortho-arylated 2-phenoxypyridines catalyzed by palladium acetate is described. Treatment of 2-phenoxypyridines with two and a half equivalents of potassium aryltrifluoroborate and 10 mol % of Pd(OAc) 2 in the presence of two equivalents of Ag2CO3, one equivalent of p-benzoquinone (BQ), and four equivalents of DMSO with (or without) H2O at 130-140 °C for 48 h in dried CH 2Cl2 gave the ortho-arylated 2-phenoxypyridines in modest to excellent yields. p-Benzoquinone is found to be an important ligand and co-oxidant for the transmetalation reductive elimination step in the catalytic reaction. The investigation of kinetic isotope effect (kH/k D) is determined to be 5.25, which indicates that C-H bond cleavage occurs in the rate-determining step. One of the arylated compounds, 2-(4′-nitrobiphenyl-2-yloxy)pyridine, was treated with methyl trifluoromethanesulfonate and subsequently sodium methoxide to give the 2-(4-nitrophenyl)phenol in 79% yield, demonstrating that pyridine is a removable directing group.
- Chu, Jean-Ho,Lin, Pi-Shan,Wu, Ming-Jung
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scheme or table
p. 4058 - 4065
(2011/01/03)
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