- Covalently Interlocked Cyclohexa-m-phenylenes and Their Assembly: En Route to Supramolecular 3D Carbon Nanostructures
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In our search to cluster as many phenylene units as possible in a given space, we have proceeded to the three-dimensional world of benzene-based molecules by employing covalently interlocked cyclohexa-m-phenylenes, as present in the unique paddlewheel-sha
- Dumslaff, Bastian,Reuss, Anna N.,Wagner, Manfred,Feng, Xinliang,Narita, Akimitsu,Fytas, George,Müllen, Klaus
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- Dual Ligand-Enabled Nondirected C-H Cyanation of Arenes
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Aromatic nitriles are key structural units in organic chemistry and, therefore, highly attractive targets for C-H activation. Herein, the development of an arene-limited, nondirected C-H cyanation based on the use of two cooperatively acting commercially available ligands is reported. The reaction enables the cyanation of arenes by C-H activation in the absence of directing groups and is therefore complementary to established approaches.
- Chen, Hao,Mondal, Arup,Wedi, Philipp,Van Gemmeren, Manuel
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p. 1979 - 1984
(2019/02/19)
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- Palladium-Catalyzed Late-Stage Direct Arene Cyanation
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Methods for direct benzonitrile synthesis are sparse, despite the versatility of cyano groups in organic synthesis and the importance of benzonitriles for the dye, agrochemical, and pharmaceutical industries. We report the first general late-stage aryl C–H cyanation with broad substrate scope and functional-group tolerance. The reaction is enabled by a dual-ligand combination of quinoxaline and an amino acid-derived ligand. The method is applicable to direct cyanation of several marketed small-molecule drugs, common pharmacophores, and organic dyes. Benzonitriles are some of the most versatile building blocks for organic synthesis, in particular in the pharmaceutical industry, but general methods to make them by direct C–H functionalization are unknown. In this issue of Chem, Ritter and coworkers describe a late-stage aryl C–H cyanation with broad substrate scope and functional-group tolerance, enabled by a palladium-dual-ligand catalyst system. The reaction may serve for the late-stage modification of drug candidates. Aryl nitriles constitute an important class of organic compounds that are widely found in natural products, pharmaceuticals, agricultural chemicals, dyes, and materials. Moreover, nitriles are versatile building blocks to access numerous other important molecular structure groups. However, no general method for direct aromatic C–H cyanation is known. All approaches to date require either an appropriate directing group or reactive electron-rich substrates, such as indoles, which limit their synthetic applications. Here we describe an undirected, palladium-catalyzed late-stage aryl C–H cyanation reaction for the synthesis of complex aryl nitriles that would otherwise be more challenging to produce. The wide substrate scope and good functional-group tolerance of this reaction provide direct and quick access to structural diversity for pharmaceutical and agrochemical development.
- Zhao, Da,Xu, Peng,Ritter, Tobias
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supporting information
p. 97 - 107
(2019/01/21)
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- Ligand-Promoted Non-Directed C?H Cyanation of Arenes
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This article reports the first example of a 2-pyridone accelerated non-directed C?H cyanation with an arene as the limiting reagent. This protocol is compatible with a broad scope of arenes, including advanced intermediates, drug molecules, and natural products. A kinetic isotope experiment (kH/kD=4.40) indicates that the C?H bond cleavage is the rate-limiting step. Also, the reaction is readily scalable, further showcasing the synthetic utility of this method.
- Liu, Luo-Yan,Yeung, Kap-Sun,Yu, Jin-Quan
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supporting information
p. 2199 - 2202
(2019/01/24)
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- A study of diketopiperazines as electron-donor initiators in transition metal-free haloarene-arene coupling
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Several diketopiperazines have been shown to promote carbon-carbon coupling between benzene and aryl halides in the presence of potassium tert-butoxide and without the assistance of a transition metal catalyst. The structure of the diketopiperazine has an influence on its reductive potential and can help to promote the coupling of the more challenging aryl bromides with benzene.
- Cumine, Florimond,Zhou, Shengze,Tuttle, Tell,Murphy, John A.
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p. 3324 - 3336
(2017/04/21)
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- Highly potent macrocyclic BACE-1 inhibitors incorporating a hydroxyethylamine core: Design, synthesis and X-ray crystal structures of enzyme inhibitor complexes
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A series of P1-P3 linked macrocyclic BACE-1 inhibitors containing a hydroxyethylamine (HEA) isostere scaffold has been synthesized. All inhibitors comprise a toluene or N-phenylmethanesulfonamide P2 moiety. Excellent BACE-1 potencies, both in enzymatic an
- Sandgren, Veronica,Agback, Tatiana,Johansson, Per-Ola,Lindberg, Jimmy,Kvarnstr?m, Ingemar,Samuelsson, Bertil,Belda, Oscar,Dahlgren, Anders
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p. 4377 - 4389
(2012/08/28)
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- (3-HYDROXY-4-AMINO-BUTAN-2-YL) -3- (2-THIAZOL-2-YL-PYRROLIDINE-1-CARBONYL) BENZAMIDE DERIVATIVES AND RELATED COMPOUNDS AS BETA-SECRETASE INHIBITORS FOR TREATING
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The present invention provides novel beta-secretase inhibitors and methods for their use, including methods of treating of Alzheimer's disease. (Formula)
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Page/Page column 91
(2009/05/29)
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- Decarboxylative photosubstitution of dicyanobenzenes with aliphatic carboxylate ions
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The photoreaction of dicyanobenzenes with aliphatic carboxylate ions afforded alkylcyanobenzenes and alkyldicyanobenzenes via decarboxylative substitution. The redox-photosensitized reaction system was effective in improving the product yield. The efficie
- Itou, Tatsuya,Yoshimi, Yasuharu,Morita, Toshio,Tokunaga, Yuji,Hatanaka, Minoru
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experimental part
p. 263 - 269
(2009/04/07)
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- Macrocyclic Compounds Useful as Bace Inhibitors
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The invention relates to novel macrocyclic compounds of the formula (I), in which all of the variables are as defined in the specification, the number of ring atoms included in the macrocyclic ring being 14, 15, 16 or 17, in free base form or in acid addition salt form, to their preparation, to their use as medicaments and to medicaments comprising them.
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Page/Page column 50
(2008/12/05)
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- MACROCYCLIC COMPOUNDS AND COMPOSITIONS USEFUL AS BACE INHIBITORS
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The invention relates to novel macrocyclic compounds of the formula in which R1, R3, V1, V2, X1, X2, Y, Z, Ar, AA and n are as defined in the specification, the number of ring atoms include
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Page/Page column 30
(2008/06/13)
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- Cyanation of Aromatic Compounds in a Gaseous Plasma
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Aromatic compounds are directly cyanated by passing cyanogen and the respective compounds through a radio-frequency generated and inductively coupled glow discharge zone.Benzene and a wide variety of substituted benzenes (C6H5X: X = CH3, t-Bu, CF3, OH, F, Cl, Br, CHO) are cyanated providing a good yield of ortho-, meta-, para-, and ipso-substituted products.The relative amount of ipso product increases as the carbon-X bond dissociation energy decreases.The ratio of ortho to meta to para cyanated products demonstrates a slight preference for substitution on electron-rich positions.A plot of the meta/para yield ratio against ?m - ?p gives a ρ value of -0.5.It is proposed that electron impact on cyanogen produces CN., which in turn attacks the aromatic, causing substitution.
- So, Y. H.,Miller, Larry L.
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p. 4204 - 4209
(2007/10/02)
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