Ueber symmetrische Biphenylderivate

Ullmann, Fritz

doi:10.1002/jlac.19043320104

Cited by 159 publications

(74 citation statements)

References 13 publications

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“…Silica gel column chromatography was performed using Merck silica gel 60 ASTM (70-230 mesh). 2-Iodothioanisole (5a) [12] and 3-iodothioanisole (5b) [13] were synthesized in 91% and 76% yields, respectively, starting from 2-(methylthio)aniline and 3-(methylthio)aniline using the procedure of Ullmann [14]. All other reagents, purchased from the Aldrich Chemical Company (Milwaukee, WI), were used without further purification.…”

Section: Methodsmentioning

confidence: 99%

Synthesis of new 1‐(2‐, 3‐, or 4‐methanesulfonylphenyl)‐2‐[5‐(N‐hydroxypyridin‐2(1H)‐one)]acetylene regioisomers: A search for novel cyclooxygenase and lipoxygenase inhibitors

Chowdhury

Chen

Abdellatif

et al. 2009

Journal of Heterocyclic Chem

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A group of acetylene regioisomers were designed such that a cyclooxygenase-2 (COX-2) SO 2 Me pharmacophore was located at the ortho-, meta-, or para-position of the acetylene C-1 phenyl ring, and an iron-chelating 5-lipoxygenase (5-LOX) N-hydroxypyridin-2(1H)-one moiety was attached via its C-5 position to the C-2 position on an acetylene template (scaffold). These target linear acetylene regioisomers were synthesized via a palladium-catalyzed Sonogashira cross-coupling reaction. Structure-activity data acquired using in vitro cell-based inhibition assays indicated that this novel class of 1-(2-, 3-, or 4-methanesulfonylphenyl)-2-[5-(N-hydroxypyridin-2(1H)-one)]acetylene regioisomers did not inhibit the COX-2 or (5-LOX) enzymes, and that they are devoid of in vivo anti-inflammatory activities.

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Section: Methodsmentioning

confidence: 99%

Synthesis of new 1‐(2‐, 3‐, or 4‐methanesulfonylphenyl)‐2‐[5‐(N‐hydroxypyridin‐2(1H)‐one)]acetylene regioisomers: A search for novel cyclooxygenase and lipoxygenase inhibitors

Chowdhury

Chen

Abdellatif

et al. 2009

Journal of Heterocyclic Chem

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“…Thanks to recent advances in surface science, we are witness of a tremendous progress in the understanding and development of on-surface chemical reactions and in the fabrication of nanostructured systems. [7][8][9] A widely used reaction in this context is derived from Ullmann coupling, 10,11 where the reactive partners are created by dehalogenation of aryl-halide precursors, 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 4 which subsequently undergo aryl-aryl coupling. 12 Recent examples of this are the formation of graphene nanoribbons and porous graphene on metal substrates.…”

mentioning

confidence: 99%

Dehalogenation and Coupling of a Polycyclic Hydrocarbon on an Atomically Thin Insulator

et al. 2014

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Catalytic activity is of pivotal relevance in enabling efficient and selective synthesis processes.Recently, covalent coupling reactions catalyzed by solid metal surfaces opened the rapidly evolving field of on-surface chemical synthesis. Tailored molecular precursors in conjunction with the catalytic activity of the metal substrate allow the synthesis of novel, technologically highly relevant materials such as atomically precise graphene nanoribbons. However, the reaction path on the metal substrate remains unclear in most cases and the intriguing question is how a specific atomic configuration between reactant and catalyst controls the reaction processes. In this study, we cover the metal substrate with a monolayer of hexagonal boron nitride (h-BN), reducing the reactivity of the metal, and gain unique access to atomistic details during the activation of a polyphenylene precursor by sequential dehalogenation and the subsequent coupling to extended oligomers. We use scanning tunneling microscopy (STM) and density functional theory (DFT) to reveal a reaction site anisotropy, induced by the registry mismatch between the precursor and the nano-structured h-BN monolayer. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 3 An atomically thin layer of insulating h-BN is a structurally analogous counterpart for graphene -a single layer of sp 2 -hybridised carbon atoms 1 -matching the graphene lattice almost perfectly with a small mismatch of approx. 2%. Currently, the fabrication of two-dimensional materials follows two main approaches: i) the bottom-up synthesis by substrate supported chemical vapor deposition (CVD) with suitable precursors and ii) the top-down approach by exfoliation. The assembly of graphene/h-BN heterostructures, leading to novel devices or devices with enhanced performance, usually relies on elaborate, sequential transfer processes of the produced layers. 2 The main obstacles are possible misalignment, introduction of defects and contaminations resulting from transferring layers that are just one atom thick. Only recently, the direct CVD growth of graphene on h-BN was demonstrated, offering superior properties. [3][4][5] However, the growth conditions are harsh (long exposure time, high temperatures, several cycles, etc.). Metal substrates are favored, because of their high catalytic activity, 6 but they have the disadvantage that they strongly alter the properties of the grown layers, which therefore cannot be directly used for electronic device fabrication.A common motif in on-surface chemical reactions is the activation of a precursor, the intermittent complex formed between precursor and substrate, and finally the coupling reaction. 7A long-standing question is the impact of the specific atomic configuration between substrate and reactant on the catalytic efficiency and how does the specific atomic arrangement chan...

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“…after crystallization from water, 353-356". Ullmann & Meyer (1904) give 356-357O.I No depression of melting point was observed on mixing with a sample of diphenyl-3 : 3'-dicarboxylic acid prepared by oxidizing 3 : 3'-dimethyldiphenyl obtained from o-tolidine (Kornblum, 1941) in a similar manner.…”

Section: Methodsmentioning

confidence: 95%

The orienting influence of the methyl group in toluene in the gomberg reaction

Wilson¹

1953

J. Appl. Chem.

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When diazotized 6‐nitro‐m‐toluidine (Me = 1) reacts with toluene, substitution occurs in the ortho‐and meta‐positions in the toluene, to give 3:2′‐dimethyl‐4‐nitrodiphenyl and 3: 3′‐dimethyl‐4‐nitrodiphenyl. The proportion of meta‐substitution is greater than that observed in electrophilic substitutionreactions with toluene, confirming conclusions drawn from the quantum‐mechanical analysis of Wheland (1942).

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Ueber symmetrische Biphenylderivate

Cited by 159 publications

References 13 publications

Synthesis of new 1‐(2‐, 3‐, or 4‐methanesulfonylphenyl)‐2‐[5‐(N‐hydroxypyridin‐2(1H)‐one)]acetylene regioisomers: A search for novel cyclooxygenase and lipoxygenase inhibitors

Synthesis of new 1‐(2‐, 3‐, or 4‐methanesulfonylphenyl)‐2‐[5‐(N‐hydroxypyridin‐2(1H)‐one)]acetylene regioisomers: A search for novel cyclooxygenase and lipoxygenase inhibitors

Dehalogenation and Coupling of a Polycyclic Hydrocarbon on an Atomically Thin Insulator

The orienting influence of the methyl group in toluene in the gomberg reaction

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