367-23-7Relevant articles and documents
Synthesis of fluorophenyl carbonyl cobalt(I) complexes and decarbonylation of 2,4,5-trifluorobenzaldehyde catalyzed by CoMe(PMe3)4
Yuan, Shuo,Sun, Hongjian,Zhang, Shumiao,Li, Xiaoyan
, p. 100 - 105 (2016)
Three fluorophenyl carbonyl cobalt(I) complexes PhF(PMe3)3Co(CO) (1-3) were synthesized by the reaction of fluoro-benzaldehydes with CoMe(PMe3)4 via C-H bond activation and decarbonylation reaction. The dicarbonyl cobalt(I) complex (2,4-F2C6H3)Co(CO)2(PMe3)2 (4) was obtained by reacting of complex 1 with CO. Complex 1 reacted with pentafluorobromobenzene afforded cobalt(II) bromide (2,4-F2C6H3)Co(Br)(PMe3)3 (5) with the formation of perfluorinated diphenyl. The reaction of complex 3 and phenylacetylene delivered the hydrido diethinyl cobalt(III) complex (PhCC)2Co(H)(PMe3)3 (6) with 1,2,4-trifluorobenzene as a byproduct. The molecular structures of 1, 4 and 5 were determined by X-ray diffraction. Furthermore, we found that CoMe(PMe3)4 could be used as a catalyst for the catalytic decarbonylation of 2,4,5-trifluorobenzaldehyde with triethylsilane as a hydrogen source.
Novel preparation method of 2, 4, 5-trifluorophenylacetic acid
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, (2021/06/23)
The invention discloses a novel preparation method of 2, 4, 5-trifluorophenylacetic acid, which belongs to the technical field of preparation of medical intermediates, and comprises the following preparation steps: carrying out nitration reaction on sulfuric acid and m-dichlorobenzene to obtain an intermediate II; adding the intermediate II, a phase transfer catalyst and potassium fluoride into an aprotic solvent to obtain an intermediate III; performing hydrogenation reaction on the intermediate III to obtain an intermediate IV; carrying out diazotization reaction on the intermediate IV, nitrosyl sulfuric acid and sodium fluoborate to obtain an intermediate V; performing cracking reaction on the intermediate V to obtain an intermediate VI; carrying out reduction reaction on the intermediate VI, and then carrying out bromination reaction on the intermediate VI and liquid bromine to obtain an intermediate VII; subjecting the intermediate VII to a substitution reaction with diethyl malonate, and obtaining 2, 4, 5-trifluorophenylacetic acid after hydrolysis and purification. A novel synthesis route is provided, the problem that technological operation is tedious is solved, the requirements for reaction and operation conditions are low, anhydrous and oxygen-free reaction conditions are not needed, the method is suitable for industrial production, and the yield and purity are greatly improved.
Hydrodefluorination of functionalized fluoroaromatics with triethylphosphine: A theoretical and experimental study
Facundo, Aldo A.,Arévalo, Alma,Fundora-Galano, Gabriela,Flores-álamo, Marcos,Orgaz, Emilio,García, Juventino J.
, p. 6897 - 6908 (2019/05/17)
Recently we reported the metal free hydrodefluorination of selected fluoroaromatics using triethylphosphine as the sole defluorinating agent. That prompted us to evaluate the mechanistic proposal and in the light of these results, along with new experimental evidence, we have now modified the initial proposal. The new mechanism avoids the highly energetic β-elimination step of roughly 71 kcal mol-1 for hexafluorobenzene and pentafluoropyridine at 393.15 K, invoking the participation of water. The use of D2O confirmed the role of water as the hydrogen source, yielding the corresponding deutero-defluorinated products; DFT calculations agree with this new proposed mechanism. We also report herein the use of this one-pot hydrodefluorination method applied to a broader number of fluoroaromatic derivatives; some of them allowed the collection of key mechanistic evidence.