372-48-5Relevant articles and documents
Nucleophilic Fluorination of Heteroaryl Chlorides and Aryl Triflates Enabled by Cooperative Catalysis
Hong, Cynthia M.,Whittaker, Aaron M.,Schultz, Danielle M.
, p. 3999 - 4006 (2021/03/09)
Aryl and heteroaryl fluorides are growing to be dominant motifs in pharmaceuticals and agrochemicals, yet they are rare in both nature and commodity chemicals. As a consequence, there is an increasingly urgent need to develop mild, cost-effective, and scalable methods for fluorination. The most straightforward route to synthesize aryl fluorides is through the halide exchange "halex"reaction, but conditions, cost, and atom economy preclude most available methods from large-scale manufacturing processes. We report a new approach that leverages the cooperative action of 18-crown-6 ether and tetramethylammonium chloride to catalytically access the reactivity of tetramethylammonium fluoride and achieve halex fluorinations under mild conditions with operational ease. The described methodology readily converts both heteroaryl chlorides and aryl triflates to their corresponding (hetero)aryl fluorides in high yields and purities.
Method for pipeline continuous fluorination with fluorine salt as fluorine source
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Paragraph 0056-0061; 0094-0096, (2021/10/27)
The method comprises the following steps: dissolving a fluorine salt in an aqueous polar aprotic solvent as reaction liquid A, dissolving an aryl (heterocyclic) chloride in a polar aprotic solvent as reaction liquid B, and reacting a polar aprotic solvent in the reaction liquid A with a polar aprotic solvent of the reaction liquid B. The reaction medium consisting of the preheated reaction liquid A and the preheated reaction liquid B enters the reaction coil for a fluorination reaction, and the resulting product from the reaction coil is subjected to post-treatment to obtain the product. The method has the characteristics of no need of adding a phase transfer catalyst, continuous production, low production cost and the like.
PROCESS FOR FLUORINATING COMPOUNDS
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Page/Page column 24, (2017/02/28)
Disclosed are mild temperature (e.g., from 0 to 80°C) SNAr fluorinations of a variety of halide and sulfonate substituted aryl and heteroaryl substrates using NMe4F.
Synthesis, Characterization, and Reactivity of Thermally Stable Anhydrous Quaternary Ammonium Fluorides
Elias, Shlomi,Karton-Lifshin, Naama,Yehezkel, Lea,Ashkenazi, Nissan,Columbus, Ishay,Zafrani, Yossi
supporting information, p. 3039 - 3042 (2017/06/23)
The synthesis and properties of a new class of anhydrous quaternary ammonium fluorides, based on the rigid skeleton azabicyclo[2.2.2]octane, is described. Compounds 2a-d were easily prepared by passing the corresponding ammonium iodides over fluoride-based resin followed by drying their hydrated form at 100 or 140 °C under reduced pressure. The stability (experimental and theoretical study), solubility, reactivity, and characterization by solution and solid-state MAS NMR are discussed.
Selective fluorination of pyridine and its derivatives in the presence of high-oxidation-state transition metals
Gryaznova,Khrizanforova,Kholin,Khrizanforov,Budnikova, Yu. H.
, p. 1798 - 1804 (2017/03/22)
The oxidative fluorination of pyridine and 4-ethylpyridine under chemical and electro-chemical conditions in the presence of transition metal (high-oxidation-state nickel, cobalt, and silver) salts was studied. The chemical fluorination affords 2-fluoropyridine in all cases, while the electrochemical fluorination results in 2-fluoroor 3-fluoropyridine depending on the catalyst used.
Dehalogenation degradation method for halogenated pyridine compound
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Paragraph 0019; 0020, (2016/12/16)
The invention provides a dehalogenation degradation method for a halogenated pyridine compound. The halogenated pyridine compound is adopted as a raw material, alcohol is adopted as a hydrogen source, water is adopted as a solvent, reacting is carried out for 3-10 h under normal pressure at the temperature of 20 DEG C to 120 DEG C under the action of a supported catalyst, and the halogenated pyridine compound is subjected to dehalogenation degradation in situ through water phase hydrogen production. A pyridine ring of the halogenated pyridine compound at least contains an F or Cl or Br or I substituent group. The supported catalyst is composed of an active component and a carrier, the active component is composed of a mixture of transition metal and other metal, the transition metal is one of Rh, Pd, Pt and Ni, and other metal is one of Se, Ca, Ba, La and Ce. The carrier is one of activated carbon, kieselguhr, zeolite, gamma-Al2O3, AlF3 and MgO. H2 is not directly used as a reduction agent, activated hydrogen is prepared through in-situ catalysis to directly participate in reacting, the advantages of being high in reaction activity, high in selectivity, high in safety, environmentally friendly and the like are achieved, and good application prospects are achieved.
Anhydrous Tetramethylammonium Fluoride for Room-Temperature SNAr Fluorination
Schimler, Sydonie D.,Ryan, Sarah J.,Bland, Douglas C.,Anderson, John E.,Sanford, Melanie S.
, p. 12137 - 12145 (2016/01/09)
This paper describes the room-temperature SNAr fluorination of aryl halides and nitroarenes using anhydrous tetramethylammonium fluoride (NMe4F). This reagent effectively converts aryl-X (X = Cl, Br, I, NO2, OTf) to aryl-F under mild conditions (often room temperature). Substrates for this reaction include electron-deficient heteroaromatics (22 examples) and arenes (5 examples). The relative rates of the reactions vary with X as well as with the structure of the substrate. However, in general, substrates bearing X = NO2 or Br react fastest. In all cases examined, the yields of these reactions are comparable to or better than those obtained with CsF at elevated temperatures (i.e., more traditional halex fluorination conditions). The reactions also afford comparable yields on scales ranging from 100 mg to 10 g. A cost analysis is presented, which shows that fluorination with NMe4F is generally more cost-effective than fluorination with CsF.
Selective C-H fluorination of pyridines and diazines inspired by a classic amination reaction
Fier, Patrick S.,Hartwig, John F.
, p. 956 - 960 (2013/12/04)
Fluorinated heterocycles are prevalent in pharmaceuticals, agrochemicals, and materials. However, reactions that incorporate fluorine into heteroarenes are limited in scope and can be hazardous. We present a broadly applicable and safe method for the site-selective fluorination of a single carbon-hydrogen bond in pyridines and diazines using commercially available silver(II) fluoride. The reactions occur at ambient temperature within 1 hour with exclusive selectivity for fluorination adjacent to nitrogen. The mild conditions allow access to fluorinated derivatives of medicinally important compounds, as well as a range of 2-substituted pyridines prepared by subsequent nucleophilic displacement of fluoride. Mechanistic studies demonstrate that the pathway of a classic pyridine amination can be adapted for selective fluorination of a broad range of nitrogen heterocycles.
FLUORINATION OF ORGANIC COMPOUNDS
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Page/Page column 25, (2012/11/06)
Methods for fluorinating organic compounds are described herein.
Deoxyfluorination of phenols
Tang, Pingping,Wang, Weike,Ritter, Tobias
supporting information; experimental part, p. 11482 - 11484 (2011/10/02)
An operationally simple ipso fluorination of phenols with a new deoxyfluorination reagent is presented.
