Replacement of the carboxylic acid function with fluorine

1986 ◽  
Vol 64 (1) ◽  
pp. 138-141 ◽  
Author(s):  
Timothy B. Patrick ◽  
Kamalesh K. Johri ◽  
David H. White ◽  
William S. Bertrand ◽  
Rodziah Mokhtar ◽  
...  
Keyword(s):  
Free Radicals ◽  
Reaction Mechanism ◽  
Room Temperature ◽  
Methylene Chloride ◽  
Chloroform Solution ◽  
Xenon Difluoride ◽  
Nucleophilic Displacement ◽  
New Process ◽  
Alkanoic Acids ◽  
Acid Function

Replacement of a carboxyl function by fluorine, fluorodecarboxylation, is a new process that can be accomplished by the reaction of alkanoic acids with xenon difluoride. Primary, tertiary, and benzylic acids perform best in the reaction, which is conducted at room temperature in methylene chloride or chloroform solution. A reaction mechanism is proposed in which the acid is initially converted to a fluoroxenon ester, RCO2XeF. The esters of the primary and secondary acids react by nucleophilic displacement by fluoride, as evidenced by incorporation of 18F− and no reactions common to free radicals or carbocations. The esters of the tertiary and benzylic acids react by converting to free radicals that can be further oxidized to carbocations. Thus incorporation of 18F− and racemization are observed with α-methoxy-α-trifluoromethylphenylacetic acid. Hydroxyl and amino functions inhibit the reaction. Aromatic and vinylic acids do not react.

scholarly journals TfOH-Promoted Reaction of 2,4-Diaryl-1,1,1-Trifluorobut-3-yn-2-oles with Arenes: Synthesis of 1,3-Diaryl-1-CF3-Indenes and Versatility of the Reaction Mechanisms

Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3079 ◽  
Author(s):  
Aleksey V. Zerov ◽  
Anna N. Kazakova ◽  
Irina A. Boyarskaya ◽  
Taras L. Panikorovskii ◽  
Vitalii V. Suslonov ◽  
...  
Keyword(s):  
Reaction Mechanism ◽  
Reaction Mechanisms ◽  
Room Temperature ◽  
Ring Closure ◽  
Nucleophilic Attack ◽  
New Process ◽  
Intramolecular Ring ◽  
Propargyl Alcohols

The TfOH-mediated reactions of 2,4-diaryl-1,1,1-trifluorobut-3-yn-2-oles (CF3-substituted diaryl propargyl alcohols) with arenes in CH2Cl2 afford 1,3-diaryl-1-CF3-indenes in yields up to 84%. This new process for synthesis of such CF3-indenes is complete at room temperature within one hour. The synthetic potential, scope, and limitations of this reaction were illustrated by more than 70 examples. The proposed reaction mechanism invokes the formation of highly reactive CF3-propargyl cation intermediates that can be trapped at the two mesomeric positions by the intermolecular nucleophilic attack of an arene partner with a subsequent intramolecular ring closure.

Room Temperature Solvent-Free Synthesis of Monodisperse Magnetite Nanocrystals

2006 ◽  
Vol 6 (3) ◽  
pp. 852-856 ◽  
Author(s):  
X. R. Ye ◽  
C. Daraio ◽  
C. Wang ◽  
J. B. Talbot ◽  
S. Jin
Keyword(s):  
Oleic Acid ◽  
Solid State ◽  
Large Scale ◽  
Room Temperature ◽  
Solvent Free ◽  
Two Dimensional ◽  
New Process ◽  
High Boiling Point ◽  
Magnetite Nanocrystals ◽  
Solvent Free Synthesis

We have successfully demonstrated a facile, solvent-free synthesis of highly crystalline and monodisperse Fe3O4 nanocrystallites at ambient temperature avoiding any heating. Solid state reaction of inorganic Fe(II) and Fe(III) salts with NaOH was found to produce highly crystalline Fe3O4 nanoparticles. The reaction, if carried out in the presence of surfactant such as oleic acid–oleylamine adduct, generated monodisperse Fe3O4 nanocrystals extractable directly from the reaction mixture. The extracted nanoparticles were capable of forming self-assembled, two-dimensional and uniform periodic array. The new process utilizes inexpensive and nontoxic starting materials, and does not require a use of high boiling point and toxic solvents, thus is amenable to an environmentally desirable, large-scale synthesis of nanocrystals.

scholarly journals Synthesis of spiro[dihydropyridine-oxindoles] via three-component reaction of arylamine, isatin and cyclopentane-1,3-dione

2013 ◽  
Vol 9 ◽  
pp. 8-14 ◽  
Author(s):  
Yan Sun ◽  
Jing Sun ◽  
Chao-Guo Yan
Keyword(s):  
Acetic Acid ◽  
Reaction Mechanism ◽  
Room Temperature ◽  
The Other ◽  
Other Hand ◽  
Three Component Reaction ◽  
High Yields

A fast and convenient protocol for the synthesis of novel spiro[dihydropyridine-oxindole] derivatives in satisfactory yields was developed by the three-component reactions of arylamine, isatin and cyclopentane-1,3-dione in acetic acid at room temperature. On the other hand the condensation of isatin with two equivalents of cyclopentane-1,3-dione gave 3,3-bis(2-hydroxy-5-oxo-cyclopent-1-enyl)oxindole in high yields. The reaction mechanism and substrate scope of this novel reaction is briefly discussed.

Molecular Rearrangements. Part IV. Aryl (Alkyl) Amines (1), Thermal Rearrangement of N-Benzyl-N-Methylaniline

1974 ◽  
Vol 52 (2) ◽  
pp. 293-298 ◽  
Author(s):  
M. Zarif A. Badr ◽  
M. M. Aly
Keyword(s):  
Free Radicals ◽  
Reaction Mechanism ◽  
Tertiary Amine ◽  
Thermal Rearrangement ◽  
Molecular Rearrangements ◽  
Intermediate Products ◽  
Alkyl Amines ◽  
Rearrangement Process ◽  
Homolytic Fission

Heating N-benzyl-N-methylaniline under reflux or heating at ∼315° in sealed tubes, in the absence of any promotor for 100 h, resulted in its rearrangement, producing methylamine, diphenylmethane, and dibenzyl together with o-toluidine and 4-methylacridine. Heating N-methylaniline in a sealed tube under the same conditions, in absence of any promotor, resulted in its rearrangement, producing methylamine and o-toluidine together with unidentified neutral products.When pyrolysis of the tertiary amine was carried out with quinoline as a solvent, the normal products of rearrangement were obtained together with 2-and 4-benzylquinolines and 2,2′-biquinolyl.The reaction mechanism is discussed on the basis of the products separated, from which it is concluded that the tertiary amine undergoes homolytic fission to benzyl and N-methylphenylamino free radicals, followed by a series of homolytic fissions of initially separated intermediate products, during the rearrangement process. Throughout the whole mechanism, the C—N bonds are the only ones to suffer homolytic fission.

scholarly journals The HNO− radical anion: A proposed intermediate in diazeniumdiolate synthesis using nitric oxide and alkoxides

2018 ◽  
Vol 25 (1) ◽  
pp. 82-85 ◽  
Author(s):  
Zhe-Chen Wang ◽  
Ya-Ke Li ◽  
Sheng-Gui He ◽  
Veronica M Bierbaum
Keyword(s):  
Nitric Oxide ◽  
Reaction Mechanism ◽  
Gas Phase ◽  
Radical Anion ◽  
Room Temperature ◽  
Hydrogen Transfer ◽  
Gas Phase Reactions ◽  
Ionic Product

The strategy of synthesizing diazeniumdiolates (X–N(O)=NO−) through the coexistence of nitric oxide and alkoxides (RO−) was introduced by Wilhelm Traube 120 years ago. Today, despite the wide use of diazeniumdiolate derivatives to release nitric oxide in the treatment of cancer, the first step of the reaction mechanism for diazeniumdiolate synthesis remains a mystery and is thought to be complex. We have studied the gas-phase reactions of nitric oxide with alkoxides at room temperature. An electron-coupled hydrogen transfer is observed, and the radical anion HNO− is the only ionic product in these reactions. HNO− can further react with nitric oxide to form N2O and HO−.

Room temperature oxidation of active sites in coal under multi-factor conditions and corresponding reaction mechanism

Fuel ◽  
2019 ◽  
Vol 256 ◽  
pp. 115901 ◽  
Author(s):  
Jinhu Li ◽  
Zenghua Li ◽  
Yongliang Yang ◽  
Junhao Niu ◽  
Qingxia Meng
Keyword(s):  
Reaction Mechanism ◽  
Active Sites ◽  
Room Temperature ◽  
Temperature Oxidation
Sign in / Sign up

Export Citation Format

Share Document