Ueber Synthesen in der Biphenylreihe

Ullmann, Fritz; Bielecki, Jean

doi:10.1002/cber.190103402141

Cited by 797 publications

(494 citation statements)

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“…Ullmann Classic Reaction is since 1901 [40], the main route to fabrication of unsubstituted biaryls. The Ullmann reaction was originally developed as a C−C coupling between aromatic halides induced by a transition metal.…”

Section: Discussionmentioning

confidence: 99%

“…The main method for the synthesis of biaryls is the Classic Ullmann Homocoupling Reaction [33] based on the transition metal-catalyzed cross-coupling reaction starting from two discrete aromatic halide entities and stoichiometric amounts of organometallic reagents, originally copper [30,[34][35][36][37][38][39]. In principle, this reaction requires harsh reaction conditions, such as large excess of phenols, high temperatures (>200 °C) and at least stoichiometric amounts of copper, which result in the production of undesirable chemical waste [40]. Besides, most of the Cu based catalysts need an extra base and/or require long reaction times [41,42].…”

Section: Introductionmentioning

confidence: 99%

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Graphene-oxide-supported CuAl and CoAl layered double hydroxides as enhanced catalysts for carbon-carbon coupling via Ullmann reaction

Ahmed

Menzel

Wang

et al. 2017

Journal of Solid State Chemistry

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Two efficient catalyst based on CuAl and CoAl layered double hydroxides (LDHs) supported on graphene oxide (GO) for the carbon-carbon coupling (Classic Ullmann Homocoupling Reaction) are reported. The pure and hybrid materials were synthesised by direct precipitation of the LDH nanoparticles onto GO, followed by a chemical, structural and physical characterization by electron microscopy, X-ray diffraction (XRD), thermogravimetric analysis (TGA), surface area measurements, X-ray photoelectron spectroscopy (XPS) and temperature programmed reduction (TPR). The GO-supported and unsupported CuAl-LDH and CoAl-LDH hybrids were tested over the Classic Ullman Homocoupling Reaction of iodobenzene. In the current study CuAl-and CoAl-LDHs have shown excellent yields (91% and 98%, respectively) at very short reaction times (25 min). GO provides a light-weight, charge complementary and two-dimensional material that interacts effectively with the 2D LDHs, in turn enhancing the stability of LDH. As a result, the recyclability of the heterogeneous catalyst systems is greatly enhanced. After 5 re-use cycles, the catalytic activity of the LDH/GO hybrid is up to 2 times higher than for the unsupported LDH.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Graphene-oxide-supported CuAl and CoAl layered double hydroxides as enhanced catalysts for carbon-carbon coupling via Ullmann reaction

Ahmed

Menzel

Wang

et al. 2017

Journal of Solid State Chemistry

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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.…”

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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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“…Cai and co-workers developed a tandem reaction for the synthesis of 1H- [1,2,3]triazolo [4,5- cycloaddition (CuAAc) and intramolecular Ullmann C-C coupling (Scheme 14) [53]. In this reaction, the intramolecular trapping of the C-Cu intermediate produced in CuAAC led to further formation of an aryl C-C bond through Ullmann C-C coupling.…”

Section: Synthesis Of Non-natural Productsmentioning

confidence: 99%

“…In 1901, Ullmann reported a useful technique for the formation of a new C-C bond between two aryls by the condensation of two molecules of aromatic halide in the presence of finely divided copper which is known as Ullmann reaction (Scheme 1) [1]. This is the first transition metal mediated coupling reaction for the formation of arylaryl bond.…”

Section: Introductionmentioning

confidence: 99%

Recent advancement of Ullmann-type coupling reactions in the formation of C–C bond

Mondal¹

2016

ChemTexts

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The present text discussed about the recent developments and applications of the Ullmann reaction in respect of the C-C bond formation. The major drawback of the Ullmann reaction, i.e., harsh reaction condition has recently been overcome with the development of various synthetic methodologies. Green synthetic methodologies such as metal-, ligand-, and additive free conditions, recyclable heterogenous catalysts, microwave-and ultrasoundassisted synthesis, etc. have got special importance in this field. This text lucidly describes all these recently developed synthetic methodologies which make the century old Ullmann reaction much efficient, effective, economical and attractive in the field of synthetic organic chemistry. Onsurface Ullmann coupling for the C-C bond formation, i.e., invoking C-C coupling reactions on a reactive surface has been discussed. All such developments of the Ullmann C-C coupling facilitate its application in the synthesis of bioactive heterocycles, drug-like molecules and natural products which has also been discussed in this text.

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Ueber Synthesen in der Biphenylreihe

Cited by 797 publications

References 3 publications

Graphene-oxide-supported CuAl and CoAl layered double hydroxides as enhanced catalysts for carbon-carbon coupling via Ullmann reaction

Graphene-oxide-supported CuAl and CoAl layered double hydroxides as enhanced catalysts for carbon-carbon coupling via Ullmann reaction

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

Recent advancement of Ullmann-type coupling reactions in the formation of C–C bond

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