Syntheses, properties, and structures of anhydrous tetramethylammonium fluoride and its 1:1 adduct with trans-3-amino-2-butenenitrile

Christe, Karl O.; Wilson, William W.; Wilson, Richard D.; Bau, Robert; Feng, Jin An

doi:10.1021/ja00177a025

Cited by 301 publications

(294 citation statements)

References 4 publications

Supporting

Mentioning

271

Contrasting

Unclassified

Order By: Relevance

“…Tetraalkylammonium fluorides are soluble in polar aprotic solvents although their hygroscopicity is such that on dissolution the fluoride will almost certainly be accompanied by varying amounts of water or some other protic material. If only traces of protic material are present, then the basicity of the solution is such that the fluoride may be capable of abstracting a proton from a weakly acid solvent such as DMSO 13 or acetonitrile 14 . Recently, Clark 15 showed that the high basicity of TMAF causes H-D exchange in 1,3-dinitrobenzene, as well as deprotonation of N,Ndimethylacetamide (DMAc).…”

Section: Resultsmentioning

confidence: 99%

Reductive debromination of 1-methyl-2,4,5-tribromoimidazole mediated by dry tetramethylammonium fluoride in aprotic solvents

Bastos

Barbosa

Pinto

et al. 2001

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

Neste trabalho investigou-se a reação entre fluoreto de tetrametilamônio seco (TMAF) e 1-metil-2,4,5-tribromoimidazol em diferentes solventes apróticos polares. Nas reações feitas em DMSO, N,N-dimetilacetamida e N-metilpirrolidona, os principais produtos foram provenientes da desbrominação redutiva e não da fluoração, como esperado, mostrando que o TMAF é fortemente básico nestas condições. A reação feita em DMSO deuterado mostrou que o solvente é a principal fonte de próton. A dimetilformamida foi o solvente menos efetivo como doador de prótons, mas forneceu um rendimento significativo do produto fluorado 4,5-dibromo-2-flúor-1-metilimidazol.The reaction of dry tetramethylammonium fluoride (TMAF) with 1-methyl-2,4,5-tribromoimidazole in different polar aprotic solvents was investigated. Products of reductive debromination were obtained rather than fluorine substitution, indicating that TMAF is strongly basic in such conditions. A reaction carried out in d 6 -DMSO showed that the solvent is the proton source. Dimethylformamide was less effective that DMSO, N,N-dimethylacetamide or Nmethylpirrolidone as a proton donor and we were able to effect significant fluorination in this solvent.

show abstract

Section: Resultsmentioning

confidence: 99%

Reductive debromination of 1-methyl-2,4,5-tribromoimidazole mediated by dry tetramethylammonium fluoride in aprotic solvents

Bastos

Barbosa

Pinto

et al. 2001

J. Braz. Chem. Soc.

View full text Add to dashboard Cite

show abstract

“…The resulting cheoical shift of -7760 ppm is 110 ppm more shielded than the most shielded value observed [7] for N(CH 3 )F in solution, The paramagnetic shielding team of free gaseous F is zero due to its spherical charge density. Taking the absolute shielding, i.e., the shielding relative to the bare fluorine nucleus, of CF11 3 , as 188.7 ppm [22), the fluoride anion has a diamagnetic shielding, od, of 448.7 ppm.…”

Section: Shielding Of the Free Gaseous Fluoride Anionmentioning

confidence: 70%

“…The 19 F NMR shift of the fluoride anion exhibits a large solvent dependence sptnniig 'a' range from -73 ppm in (CH3)2SO to -148 ppm in CH 3 OH solution (7,8]. The' shielding of.a nucleus can be separated into two main contributions, the diamagnetic -shielding and the paramagnetic shielding.…”

Section: Introductionmentioning

confidence: 99%

Are 19F NMR Shifts a Measure for the Nakedness of Fluoride Ions?

Gerken¹,

Boatz²,

Kornath³

et al. 2002

View full text Add to dashboard Cite

“…For a monoatomic cation, such as Cs"^, they become -RT and Vi RT for UporiCF) and UpoiiCAF), respectively, but their sum remains unchanged. The reaction enthalpies for (1) are then given for both polyatomic and monatomic cations by equation (2).…”

Section: General Description Of the Methodsmentioning

confidence: 99%

“…The reaction enthalpies for reaction (1) were estimated for the above seven fluoride ion donors and four Lewis acids using equation (2). Substitution of the FIA values in (2) by the Christe/Dixon pF, Lewis acidity, values, which are defined by (4)…”

Section: Estimation Of Reaction Enthalpies and Free Energies From Thementioning

confidence: 99%

Quantitative Measure for the Nakedness of Fluoride Ion Sources

Jenkins¹

2003

Self Cite

View full text Add to dashboard Cite

Public reporting burden for this collection of information is estimated to average 1 hour per response, including the time for reviewing instmctions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing this collection of information. Send comments regarding this burden estimate or any other aspect of this collection of Information, including suggestions for redudng this burden to Department of Defense, Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215 Jefferson Davis Highway, Suite 1204, Arlington, VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law, no person shall be subject to any penalty for failing to comply with a collection of infomiation if it does not disolav a currentiv valid 0MB control number. PLEASE DO NOT RETURN YOUR FORM TO THE ABOVE ADDRESS. (TMASbFe)) = 69 kJ moF'], a four times larger cation (phosphazenium salt) and an infinitely large cation are required to decrease AUPOT to 17 and zero kJ mol'', respectively. These results clearly demonstrate that very little is gained by increasing the cation size past a certain level and that secondary factors, such as chemical and physical properties, become oveniding considerations. REPORT DATE (DD-MM-YTT/)

show abstract

Syntheses, properties, and structures of anhydrous tetramethylammonium fluoride and its 1:1 adduct with trans-3-amino-2-butenenitrile

Cited by 301 publications

References 4 publications

Reductive debromination of 1-methyl-2,4,5-tribromoimidazole mediated by dry tetramethylammonium fluoride in aprotic solvents

Reductive debromination of 1-methyl-2,4,5-tribromoimidazole mediated by dry tetramethylammonium fluoride in aprotic solvents

Are 19F NMR Shifts a Measure for the Nakedness of Fluoride Ions?

Quantitative Measure for the Nakedness of Fluoride Ion Sources

Contact Info

Product

Resources

About