F:Flammable;
563-80-4Relevant articles and documents
Reactivation of Boron Phosphate Catalysts for the Synthesis of Isoprene from 2-Methylbutanal Dehydration
Hutchings, Graham J.,Hudson, Ian D.,Timms, Donald G.
, p. 2717 - 2718 (1994)
Boron phosphate catalysts, when used for the title reaction, are deactivated both by coke deposition and by loss of surface phosphorus; air reactivation at 800 deg C is shown to totally restore the catalyst structure and performance.
Trifluoroacetylation of ketone O-vinyloximes
Vasil'tsov,Shmidt,Mikhaleva,Zaitsev,Tarasova,Afonin,Toryashinova,Il'icheva,Trofimov
, p. 334 - 338 (2001)
Ketone oxime O-vinyl ethers having alkyl or phenyl radicals react with trifluoroacetic anhydride in ether in the presence of pyridine, yielding 43-54% of the corresponding ketone oxime O-(trans-4,4,4-trifluoro-3-oxo-1-butenyl) ethers with high stereoselec
Oxidation of an αβ-(epoxyalkyl) trimethylsilane with pyridine oxides in the presence of silylating agents. A facile enantioselective synthesis of glyceraldehyde derivatives
Raubo, Piotr,Wicha, Jerzy
, p. 3387 - 3390 (1994)
Trimethylsilyl glycidol derivatives 1 were oxidized with pyridine N-oxides in the presence of silylating agents to give the corresponding glyceraldehyde derivatives 3. Reaction of (α,β-epoxyalkyl)silanes with N-oxides was studied.
Acid-catalyzed isomerization of pivalaldehyde to methyl isopropyl ketone via a reactive protosolvated carboxonium ion intermediate
Olah,Mathew,Marinez,Esteves,Etzkorn,Rasul,Surya Prakash
, p. 11556 - 11561 (2001)
Quantitative rearrangement of pivalaldehyde to methyl isopropyl ketone is observed in acids such as trifluoromethanesulfonic acid, anhydrous HF, and trifluoroethyl alcohol - BF3 but not in trifluoroacetic acid. Studies in a mixture of trifluoroacetic acid and trifluoromethanesulfonic acid show that acids with Ho ≤ - 11 are able to carry out complete isomerization. These results and density functional theory calculations at the B3LYP/6-31 G* level suggest that protonated pivalaldehyde undergoes further protosolvation at higher acidities to a reactive superelectrophilic species resulting in rearrangement. A mechanism for the pivalaldehyde rearrangement to methyl isopropyl ketone in strong protic acids involving a reactive protosolvated superelectrophilic intermediate is suggested. Aspects of the related mechanism of the reaction with isobutane with CO in HF/BF3 medium leading to methyl isopropyl ketone are also discussed.
Oxidation of Saturated Hydrocarbons by Hydrogen Peroxide in Pyridine Solution Catalysed by Copper and Iron Perchlorates
Geletii, Yurii V.,Lavrushko, Valentina V.,Lubimova, Galina V.
, p. 936 - 937 (1988)
Oxidation of secondary C-H bonds of saturated hydrocarbons (C6H12, 2-methylbutane) by H2O2 in the presence of copper or iron perchlorates in pyridine solution yields the ketone and alcohol with alkyl radicals not being intermediates.
Chromium-Catalyzed Production of Diols From Olefins
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Paragraph 0111, (2021/03/19)
Processes for converting an olefin reactant into a diol compound are disclosed, and these processes include the steps of contacting the olefin reactant and a supported chromium catalyst comprising chromium in a hexavalent oxidation state to reduce at least a portion of the supported chromium catalyst to form a reduced chromium catalyst, and hydrolyzing the reduced chromium catalyst to form a reaction product comprising the diol compound. While being contacted, the olefin reactant and the supported chromium catalyst can be irradiated with a light beam at a wavelength in the UV-visible spectrum. Optionally, these processes can further comprise a step of calcining at least a portion of the reduced chromium catalyst to regenerate the supported chromium catalyst.
Hydration of Alkynes to Ketones with an Efficient and Practical Polyoxomolybdate-based Cobalt Catalyst
Xie, Ya,Wang, Jingjing,Wang, Yunyun,Han, Sheng,Yu, Han
, p. 4985 - 4989 (2021/10/12)
Hydration of alkynes to ketones is one of the most atom economical and universal methods for the synthesis of carbonyl compounds. However, the basic reaction usually requires organic ligand catalysts or harsh reaction conditions to insert oxygen into the C≡C bond. Here, we report an inorganic ligand supported cobalt (III) catalyst, (NH4)3[CoMo6O18(OH)6], which is supported by a central cobalt (III) mononucleus and a ring-shaped pure inorganic ligand composed of six MoVIO6 octahedrons to avoid the disadvantages of expensive and unrecyclable organic ligand catalysts or noble metal catalysts. Under mild conditions, the cobalt (III) catalyst can be used for the hydration of alkynes to ketones. The catalyst is non-toxic, green, and environment friendly. The catalyst can be recycled at least six times with high activity. According to control experiments, a reasonable mechanism is provided.
Dual utility of a single diphosphine-ruthenium complex: A precursor for new complexes and, a pre-catalyst for transfer-hydrogenation and Oppenauer oxidation
Mukherjee, Aparajita,Bhattacharya, Samaresh
, p. 15617 - 15631 (2021/05/19)
The diphosphine-ruthenium complex, [Ru(dppbz)(CO)2Cl2] (dppbz = 1,2-bis(diphenylphosphino)benzene), where the two carbonyls are mutually cis and the two chlorides are trans, has been found to serve as an efficient precursor for the synthesis of new complexes. In [Ru(dppbz)(CO)2Cl2] one of the two carbonyls undergoes facile displacement by neutral monodentate ligands (L) to afford complexes of the type [Ru(dppbz)(CO)(L)Cl2] (L = acetonitrile, 4-picoline and dimethyl sulfoxide). Both the carbonyls in [Ru(dppbz)(CO)2Cl2] are displaced on reaction with another equivalent of dppbz to afford [Ru(dppbz)2Cl2]. The two carbonyls and the two chlorides in [Ru(dppbz)(CO)2Cl2] could be displaced together by chelating mono-anionic bidentate ligands, viz. anions derived from 8-hydroxyquinoline (Hq) and 2-picolinic acid (Hpic) via loss of a proton, to afford the mixed-tris complexes [Ru(dppbz)(q)2] and [Ru(dppbz)(pic)2], respectively. The molecular structures of four selected complexes, viz. [Ru(dppbz)(CO)(dmso)Cl2], [Ru(dppbz)2Cl2], [Ru(dppbz)(q)2] and [Ru(dppbz)(pic)2], have been determined by X-ray crystallography. In dichloromethane solution, all the complexes show intense absorptions in the visible and ultraviolet regions. Cyclic voltammetry on the complexes shows redox responses within 0.71 to -1.24 V vs. SCE. [Ru(dppbz)(CO)2Cl2] has been found to serve as an excellent pre-catalyst for catalytic transfer-hydrogenation and Oppenauer oxidation.
Br?nsted Acid Catalyzed Tandem Defunctionalization of Biorenewable Ferulic acid and Derivates into Bio-Catechol
Bal, Mathias,Bomon, Jeroen,Liao, Yuhe,Maes, Bert U. W.,Sels, Bert F.,Sergeyev, Sergey,Van Den Broeck, Elias,Van Speybroeck, Veronique
supporting information, p. 3063 - 3068 (2020/02/05)
An efficient conversion of biorenewable ferulic acid into bio-catechol has been developed. The transformation comprises two consecutive defunctionalizations of the substrate, that is, C?O (demethylation) and C?C (de-2-carboxyvinylation) bond cleavage, occurring in one step. The process only requires heating of ferulic acid with HCl (or H2SO4) as catalyst in pressurized hot water (250 °C, 50 bar N2). The versatility is shown on a variety of other (biorenewable) substrates yielding up to 84 % di- (catechol, resorcinol, hydroquinone) and trihydroxybenzenes (pyrogallol, hydroxyquinol), in most cases just requiring simple extraction as work-up.
Solvent-free, microwave assisted oxidation of alcohols with 4-hydroxypyridinium chlorochromate functionalized silica gel
AHMADI, Sayed Ali,GHALEHBANDI, Shermineh Sadat,GHAZANFARI, Dadkhoda,SHEIKHHOSSEINI, Enayatollah
, p. 283 - 289 (2020/10/06)
4-Hydroxypyridinium chlorochromate functionalized silica gel was found to be an efficient and reusable oxidant for the very fast oxidation of primary and secondary alcohols to the corresponding carbonyl compounds under solventfree conditions and microwave irradiation in excellent yields.
