462-06-6Relevant articles and documents
Fluoroaromatics from arylamines, a convenient one-pot conversion using nitrosonium tetrafluoroborate
Milner
, p. 73 - 82 (1992)
A simple, novel and extremely versatile procedure has been identified for the conversion of arylamines into the corresponding arylfluorides. The amine is treated with nitrosonium tetrafluoroborate in dichloromethane and the resulting diazonium tetrafluoroborate is heated, without isolation or drying, to give the fluoroaromatic, generally in good yield. The method is applicable even to arylamines bearing carboxyl and hydroxyl substituents which give poor yields of arylfluorides under Balz-Schiemann conditions.
Cleavage of Aryl-Tin Bonds with Elemental Fluorine: Rapid Synthesis of Fluorobenzene
Adam, Michael J.,Pate, Brian D.,Ruth, Thomas J.,Berry, Joffre M.,Hall, Laurance D.
, p. 733 (1981)
Fluorobenzene has been synthesized rapidly by treatment of aryltin derivatives with F2 in CFCl3 or CCl4 at -78 to 0 deg C.
Activation of Aryl Halides by Nickel(I) Pincer Complexes: Reaction Pathways of Stoichiometric and Catalytic Dehalogenations
Rettenmeier, Christoph A.,Wenz, Jan,Wadepohl, Hubert,Gade, Lutz H.
, p. 8214 - 8224 (2016)
Homolytic C-X bond cleavage of organohalides by the T-shaped nickel(I) complexes [LigNiI] 1 bearing the iso-PyrrMeBox ligand had been found previously to be the crucial activation step in the asymmetric hydrodehalogenation of geminal dihalides. Here, this mechanistic investigation is extended to aryl halides, which allowed a systematic study of the activation process by a combination of experimental data and density functional theory modeling. While the activation of both aryl chlorides and geminal dichlorides appears to proceed via an analogous transition state, the generation of a highly stabile nickel(II)aryl species in the reaction of the aryl chlorides for the former represents a major difference in the reactive behavior. This difference was found to have a crucial impact on the activity of these nickel pincer systems as catalysts in the dehalogenation of aryl chlorides compared to geminal dichlorides and highlights the importance of the regulatory pathways controlling the nickel(I) concentration throughout the catalysis. These results along with the identification and characterization of novel nickel(II)aryl species are presented.
Preparation of Fluoroarenes in One-Pot Diazotization and Fluoro-Dediazoniation of Aminoarenes Using HF or HF-Base. The Functions of Bases in the HF Solution
Fukuhara, Tsuyoshi,Sasaki, Satoshi,Yoneda, Norihiko,Suzuki, Akira
, p. 2058 - 2062 (1990)
In a one-pot diazotization of anilines followed by fluoro-dediazoniation in situ using HF or HF with bases (HF-Base) as a solvent, the diazotization stage has been found to play the most important part to yield fluoroarenes effectively.Diazotization of anilines was greatly influenced by the composition of the HF solution, and greatly enhanced by employing appropriate amounts of bases, such as pyridine.On the other hand, fluoro-dediazoniation of diazonium salts, once formed, took place very readily in HF or HF-Base to produce fluoroarenes in high yield, although such bases served to slow down the rate of decomposition of diazonium salts to some extent.
Energy Disposal in Gas-phase Nucleophilic Displacement Reactions
VanOrden, Steven L.,Pope, R. Marshall,Buckner, Steven W.
, p. 1003 - 1007 (1991)
The partitioning of reaction exothermicity into relative translational energy of the products of gas-phase SN2 (F- + CH3Cl) and nucleophilic aromatic substitution F- + C6H5Cl) reactions has been investigated using kinetic energy release Fourier transform ion cyclotron resonance spectroscopy.The chloride product ion is observed to be highly translationally excited for the Sn2 reaction, indicating a cold internal energy distribution for the products.For the chlorobenzene reaction the products are not generated with large translational energies.The results are compa red with a statistical model.Ion-intensity profiles for the CH3Cl reaction deviate significantly from the statistical model whereas the chlorobenzene results are consistent with this model.The kinetic energy release for the CH3Cl reaction is compared with energy-diposal results for the photodissociation and dissociative electron-attachment processes of halomethanes.In all three cases a node in the molecular orbital between the carbon atom and the departing halogen results in a repulsive energy release.Ion-retention curves for the nucleophilic aromatic substitution reaction are consistent with the existence of a long-lived ion-dipole complex on the exit channel for this reaction.
Taming the Lewis Superacidity of Non-Planar Boranes: C?H Bond Activation and Non-Classical Binding Modes at Boron
Berionni, Guillaume,Champagne, Beno?t,Chardon, Aurélien,Fusaro, Luca,Mahaut, Damien,Osi, Arnaud,Tumanov, Nikolay,Wouters, Johan
supporting information, (2022/01/20)
The rational design of a geometrically constrained boron Lewis superacid featuring exceptional structure and reactivity is disclosed. It enabled the formation of non-classical electron deficient B?H?B type of bonding, which was supported by spectroscopic and structural parameters as well as computational studies. Taming the pyramidal Lewis acid electrophilicity through weak coordinating anion dissociation enabled a series of highly challenging chemical transformations, such as Csp2?H and Csp3?H activation under a frustrated Lewis pair regime and the cleavage of Csp3?Si bonds. The demonstration of such rich chemical behaviour and flexibility on a single molecular compound makes it a unique mediator of chemical transformations generally restricted to transition metals.
Photochemical Sandmeyer-type Halogenation of Arenediazonium Salts
Belitz, Florian,Goo?en, Lukas J.,Manu Martínez, ángel,Schmid, Rochus,Sivendran, Nardana,Sowa Prendes, Daniel
, (2022/01/19)
Trihalide salts were found to efficiently promote photochemical dediazotizing halogenations of diazonium salts. In contrast to classical Sandmeyer reactions, no metal catalysts are required to achieve high yields and outstanding selectivities for halogena
Process for Preparing Fluorobenzene by Direct Fluorination
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Paragraph 0176-0184, (2021/02/26)
The invention relates to a use of a fluorination gas, wherein the elemental fluorine (F2) is present in a high concentration, for example, in a concentration of elemental fluorine (F2), especially of equal to much higher than 15% or even 20% by volume (i.e., at least 15% or even 20% by volume), and to a process for the manufacture of a fluorinated benzene by direct fluorination employing a fluorination gas, wherein the elemental fluorine (F2) is present in a high concentration. The process of the invention is directed to the manufacture of a fluorinated benzene by direct fluorination. Especially the invention is of interest in the preparation of fluorinated benzene, final products and as well intermediates, for usage in agro-, pharma-, electronics-, catalyst, solvent and other functional chemical applications. The fluorination process of the invention may be performed batch-wise or in a continuous manner. If the process of the invention is performed batch-wise, a column (tower) reactor may be used. If the process of the invention is continuous a microreactor may be used. The invention is characterized in that the starting compound is benzene, and the fluorinated compound produced is a fluorinated benzene, preferably monofluorobenzene.
Metal-Free Photoredox-Catalyzed Hydrodefluorination of Fluoroarenes Utilizing Amide Solvent as Reductant
Toriumi, Naoyuki,Yamashita, Kazuya,Iwasawa, Nobuharu
supporting information, p. 12635 - 12641 (2021/08/03)
A metal-free photoredox-catalyzed hydrodefluorination of fluoroarenes was achieved by using N,N,N’,N’-tetramethyl-para-phenylenediamine (1) as a strong photoreduction catalyst. This reaction was applicable not only to electron-rich monofluoroarenes but also to polyfluoroarenes to afford non-fluorinated arenes. The experimental mechanistic studies indicated that the amide solvent NMP plays an important role for regeneration of the photocatalyst, enabling additive-free photoreduction catalysis.
Decarboxylative Hydroxylation of Benzoic Acids
Ritter, Tobias,Su, Wanqi,Xu, Peng
supporting information, p. 24012 - 24017 (2021/10/06)
Herein, we report the first decarboxylative hydroxylation to synthesize phenols from benzoic acids at 35 °C via photoinduced ligand-to-metal charge transfer (LMCT)-enabled radical decarboxylative carbometalation. The aromatic decarboxylative hydroxylation is synthetically promising due to its mild conditions, broad substrate scope, and late-stage applications.
