766-11-0Relevant articles and documents
Tetramethylammonium Fluoride Alcohol Adducts for SNAr Fluorination
Bland, Douglas C.,Lee, So Jeong,Morales-Colón, Mariá T.,Sanford, Melanie S.,Scott, Peter J. H.,See, Yi Yang
supporting information, p. 4493 - 4498 (2021/06/28)
Nucleophilic aromatic fluorination (SNAr) is among the most common methods for the formation of C(sp2)-F bonds. Despite many recent advances, a long-standing limitation of these transformations is the requirement for rigorously dry, aprotic conditions to maintain the nucleophilicity of fluoride and suppress the generation of side products. This report addresses this challenge by leveraging tetramethylammonium fluoride alcohol adducts (Me4NF·ROH) as fluoride sources for SNAr fluorination. Through systematic tuning of the alcohol substituent (R), tetramethylammonium fluoride tert-amyl alcohol (Me4NF·t-AmylOH) was identified as an inexpensive, practical, and bench-stable reagent for SNAr fluorination under mild and convenient conditions (80 °C in DMSO, without the requirement for drying of reagents or solvent). A substrate scope of more than 50 (hetero) aryl halides and nitroarene electrophiles is demonstrated.
PROCESS FOR FLUORINATING COMPOUNDS
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Page/Page column 29; 33; 35, (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.
Acyl azolium fluorides for room temperature nucleophilic aromatic fluorination of chloro- and nitroarenes
Ryan, Sarah J.,Schimler, Sydonie D.,Bland, Douglas C.,Sanford, Melanie S.
supporting information, p. 1866 - 1869 (2015/04/27)
The reaction of acid fluorides with N-heterocyclic carbenes (NHCs) produces anhydrous acyl azolium fluorides. With appropriate selection of acid fluoride and NHC, these salts can be used for the room temperature SNAr fluorination of a variety of aryl chlorides and nitroarenes.
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.
Tetrabutylammonium salt induced denitration of nitropyridines: Synthesis of fluoro-, hydroxy-, and methoxypyridines
Kuduk, Scott D.,DiPardo, Robert M.,Bock, Mark G.
, p. 577 - 579 (2007/10/03)
(Chemical Equation Presented) An efficient method for the synthesis of fluoropyridines via the fluorodenitration reaction is reported. The reaction is mediated by tetrabutylammonium fluoride (TBAF) under mild conditions without undue regard to the presence of water. The fluorodenitration is general for 2- or 4-nitro-substituted pyridines, while 3-nitropyridines require attendant electron-withdrawing groups for the reaction to proceed efficiently. Nitropyridines also undergo hydroxy- and methoxydenitration under mild conditions in the presence of the corresponding tetrabutylammonium species.
Therapeutic phenoxyalkylheterocycles
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, (2008/06/13)
Compounds of the formula STR1 wherein Q is chosen from the group consisting of pyridyl, pyrazyl, pyrimidyl, quinolyl, indolyl and 7-azaindolyl or any of these substituted with one or two substituents; Y is an alkylene bridge of 3-9 carbon atoms; R1 and R2 are each independently chosen from hydrogen, halo, alkyl, alkenyl, amino, alkylthio, hydroxy, hydroxyalkyl, alkoxyalkyl, alkylthioalkyl, alkylsulfinylalkyl, alkylsulfonylalkyl, alkoxy, nitro, carboxy, alkoxycarbonyl, dialkylaminoalkyl, alkylaminoalkyl, aminoalkyl, difluoromethyl, trifluoromethyl or cyano; R3 is alkoxycarbonyl, alkyltetrazolyl, substituted or unsubstituted phenyl or heterocyclyl, the N-oxide thereof, or a pharmaceutically acceptable acid addition salt thereof is an effective antipicornaviral agent.
Method for preparing 2,5-dihalo- and 2,5,6-trihalopyridines
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, (2008/06/13)
A method for preparing 2,5-dihalo- and 2,5,6-trihalopyridines corresponding to the formula SPC1 Wherein each X independently represents chloro, fluoro or bromo and R represents hydrogen, chloro, fluoro or bromo which comprises reacting a halohydrazinopyridine of one of the formulas SPC2 With an excess of an aqueous alkali metal hydroxide in the presence of a reaction medium from the group consisting of loweralkanols of 1 to 4 carbon atoms and loweralkylglycols of 2 to 4 carbon atoms.
