- Enzyme-like Supramolecular Iridium Catalysis Enabling C?H Bond Borylation of Pyridines with meta-Selectivity
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The use of secondary interactions between substrates and catalysts is a promising strategy to discover selective transition metal catalysts for atom-economy C?H bond functionalization. The most powerful catalysts are found via trial-and-error screening due to the low association constants between the substrate and the catalyst in which small stereo-electronic modifications within them can lead to very different reactivities. To circumvent these limitations and to increase the level of reactivity prediction in these important reactions, we report herein a supramolecular catalyst harnessing Zn???N interactions that binds to pyridine-like substrates as tight as it can be found in some enzymes. The distance and spatial geometry between the active site and the substrate binding site is ideal to target unprecedented meta-selective iridium-catalyzed C?H bond borylations with enzymatic Michaelis–Menten kinetics, besides unique substrate selectivity and dormant reactivity patterns.
- Al-Shehimy, Shaymaa,Gramage-Doria, Rafael,Roisnel, Thierry,Trouvé, Jonathan,Zardi, Paolo
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supporting information
p. 18006 - 18013
(2021/05/07)
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- Understanding the Activation of Air-Stable Ir(COD)(Phen)Cl Precatalyst for C-H Borylation of Aromatics and Heteroaromatics
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A newly developed robust catalyst [Ir(COD)(Phen)Cl] (A) was used for the C-H borylation of three dozen aromatics and heteroaromatics with excellent yield and selectivity. Activation of the catalyst was identified by the use of catalytic amounts of water, alcohols, etc., when B2pin2 was used in noncoordinating solvents, while for THF catalytic use of HBpin was required. The results were on par with the in situ based expensive system [Ir(OMe)(COD)]2/dtbbpy or Me4Phen.
- Slack, Eric D.,Colacot, Thomas J.
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supporting information
p. 1561 - 1565
(2021/02/20)
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- Design, synthesis and biological evaluation of 1H-indazole derivatives as novel ASK1 inhibitors
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Apoptosis signal-regulating kinase 1 (ASK1, MAP3K5), a member of the mitogen-activated protein kinase (MAPK) signaling pathway, is involved in cell survival, differentiation, stress response, and apoptosis. ASK1 kinase inhibition has emerged as a promisin
- Hou, Shaohua,Yang, Xiping,Yang, Yuejing,Tong, Yu,Chen, Quanwei,Wan, Boheng,Wei, Ran,Lu, Tao,Chen, Yadong,Hu, Qinghua
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- meta-Nitration of Arenes Bearing ortho/para Directing Group(s) Using C?H Borylation
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Herein, we report the meta-nitration of arenes bearing ortho/para directing group(s) using the iridium-catalyzed C?H borylation reaction followed by a newly developed copper(II)-catalyzed transformation of the crude aryl pinacol boronate esters into the corresponding nitroarenes in a one-pot fashion. This protocol allows the synthesis of meta-nitrated arenes that are tedious to prepare or require multistep synthesis using the existing methods. The reaction tolerates a wide array of ortho/para-directing groups, such as ?F, ?Cl, ?Br, ?CH3, ?Et, ?iPr ?OCH3, and ?OCF3. It also provides regioselective access to the nitro derivatives of π-electron-deficient heterocycles, such as pyridine and quinoline derivatives. The application of this method is demonstrated in the late-stage modification of complex molecules and also in the gram-scale preparation of an intermediate en route to the FDA-approved drug Nilotinib. Finally, we have shown that the nitro product obtained by this strategy can also be directly converted to the aniline or hindered amine through Baran's amination protocol.
- Li, Xuejing,Deng, Xingwang,Coyne, Anthony G.,Srinivasan, Rajavel
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supporting information
p. 8018 - 8023
(2019/05/29)
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- Sterically controlled C-H/C-H homocoupling of arenes: Via C-H borylation
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A mild one-pot protocol for the synthesis of symmetrical biaryls by sequential Ir-catalyzed C-H borylation and Cu-catalyzed homocoupling of arenes is described. The regiochemistry of the biaryl formed is sterically controlled as dictated by the C-H borylation step. The methodology is also successfully extended to heteroarenes. Some of the products obtained by this approach are impossible to obtain via the Ullmann or the Suzuki coupling protocols. Finally, we have shown a one-pot sequence describing C-H borylation/Cu-catalyzed homocoupling/Pd-catalyzed Suzuki coupling to obtain π-extended arene frameworks.
- Pei, Xiaocong,Zhou, Guan,Li, Xuejing,Xu, Yuchen,Panicker, Resmi C.,Srinivasan, Rajavel
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supporting information
p. 5703 - 5707
(2019/06/19)
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- Difluorene compound and organic electroluminescence device containing same
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The invention provides a difluorene compound and an organic electroluminescence device containing the same, and belongs to the technical field of organic optoelectronic materials. The compound is of the structure as shown in the formula (I), and the difluorene compound has a larger conjugate plane structure, so that the electron mobility is high; electron-deficient groups of pyridine, pyrimidine and triazine structures are introduced, which is more beneficial to electron accepting, thus the difluorene compound has good transmission performance; a bridged linkage structure is introduced, on onehand, the molecular weight of the compound can be increased to make a obtained material has high glass-transition temperature and prevent the crystallization effect, and on the other hand, the type of derivatives have certain distortion on the spatial three-dimensional structures to improve the film-forming property of the derivatives. The organic electroluminescence device prepared by using thecompound as a main body material of a luminescence layer has the advantages of being low in driving voltage and high in luminescence efficiency and is an organic luminescence material with excellent performance.
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Paragraph 0086-0088; 0091-0092
(2018/11/22)
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- PHOSPHOROUS HOST MATERIAL AND ORGANIC ELECTROLUMINESCENT DEVICE COMPRISING THE SAME
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The present invention relates to phosphorous host materials and an organic electroluminescent device comprising the same. By using the phosphorous host material of the present invention, an organic electroluminescent device having significantly improved o
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Paragraph 220-221
(2016/12/12)
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- A modular synthesis of teraryl-based α-helix mimetics, part 2: Synthesis of 5-pyridine boronic acid pinacol ester building blocks with amino acid side chains in 3-position
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One of the most common protein-protein interactions (PPI) is the interaction of the α-helix of one protein with the surface of the second one. Terphenylic scaffolds are bioinspired motifs in the inhibition of PPIs and have been identified as suitable α-helix mimetics. One of the challenging aspects of this strategy is the poor solubility of terphenyls under physiological conditions. In the literature pyrrolopyrimidine-, pyrimidine- or pyridazine-based mimetics have been reported to show improved solubility. We present a new convergent strategy for the synthesis of linear pyridine-type teraryls based on a phenylic core unit. A general approach for the synthesis of 3,5-disubstituted pyridine-based boronic acid pinacol esters with amino acid side chains in the 3-position (representing Phe, Leu, Ile, Lys, Asp, Asn) is presented and exploits the functional group tolerance of the Knochel-Grignard reagents. The building blocks have been used in a convergent in situ two-step synthesis of teraryl α-helix mimetics. Tune in: The chemical orthogonality of Knochel's Grignard chemistry enables the synthesis of 3-substituted 5-pyridine-boronic esters with amino acid side chains, which can be used for convenient assembly of teraryl-based α-helix peptide mimetics by Suzuki coupling (see scheme; dppf=1,1′-bis(diphenylphosphino)ferrocene, DME= dimethoxyethane, Tf=trifluoromethanesulfonyl). Copyright
- Peters, Martin,Trobe, Melanie,Breinbauer, Rolf
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supporting information
p. 2450 - 2456
(2013/03/28)
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- 5-HETEROARYL THIAZOLES AND THEIR USE AS P13K INHIBITORS
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The invention provides thiazole derivatives of formula (I), or pharmaceutically acceptable salts thereof in which Ring A, R1, R2 and R3 are as defined in the specification; a processes for their preparation; pharmaceutical compositions containing them; and their use in therapy, for example in the treatment of disease mediated by a PI3K enzyme and/or a mTOR kinase.
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Page/Page column 140
(2010/11/30)
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- Synthesis of novel halopyridinylboronic acids and esters. Part 2: 2,4, or 5-Halopyridin-3-yl-boronic acids and esters
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This paper describes a general method for the synthesis and the isolation of novel 2,4, or 5-halopyridin-3-yl-boronic acids and esters 4, 7, 10, 13, 15. These compounds are prepared taking into account a regioselective halogen-metal exchange using nBuLi or a regioselective ortho-lithiation using lithium diisopropylamide and subsequent quenching with triisopropylborate starting from appropriate mono or dihalopyridines. All substrates studied to date provided a single regioisomeric boronic acid or ester product. Additionally, these compounds have been found to undergo Pb-catalyzed coupling with a range of arylhalides and authorize a strategy to produce new pyridines libraries.
- Bouillon, Alexandre,Lancelot, Jean-Charles,Collot, Valerie,Bovy, Philippe R.,Rault, Sylvain
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p. 3323 - 3328
(2007/10/03)
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