2057-87-6Relevant academic research and scientific papers
Oxidative Dehomologation of Aldehydes with Oxygen as a Terminal Oxidant
Shipilovskikh, Sergei A.,Rubtsov, Aleksandr E.,Malkov, Andrei V.
supporting information, p. 6760 - 6762 (2017/12/26)
A mild, efficient protocol for oxidative cleavage of C-C bonds in aldehydes has been developed that employs alkali metal hydrides as reagents and oxygen from air as a terminal oxidant. The method is applicable to a broad substrate range.
Efficient Visible Light-Driven Splitting of Alcohols into Hydrogen and Corresponding Carbonyl Compounds over a Ni-Modified CdS Photocatalyst
Chai, Zhigang,Zeng, Ting-Ting,Li, Qi,Lu, Liang-Qiu,Xiao, Wen-Jing,Xu, Dongsheng
supporting information, p. 10128 - 10131 (2016/08/31)
Splitting of alcohols into hydrogen and corresponding carbonyl compounds has potential applications in hydrogen production and chemical industry. Herein, we report that a heterogeneous photocatalyst (Ni-modified CdS nanoparticles) could efficiently split alcohols into hydrogen and corresponding aldehydes or ketones in a stoichiometric manner under visible light irradiation. Optimized apparent quantum yields of 38%, 46%, and 48% were obtained at 447 nm for dehydrogenation of methanol, ethanol, and 2-propanol, respectively. In the case of dehydrogenation of 2-propanol, a turnover number of greater than 44-000 was achieved. To our knowledge, these are unprecedented values for photocatalytic splitting of liquid alcohols under visible light to date. Besides, the current catalyst system functions well with other aliphatic and aromatic alcohols, affording the corresponding carbonyl compounds with good to excellent conversion and outstanding selectivity. Moreover, mechanistic investigations suggest that an interface between Ni nanocrystal and CdS plays a key role in the reaction mechanism of the photocatalytic splitting of alcohol.
Efficient solvent-free synthesis of thiazolidin-4-ones from phenylhydrazine and 2,4-dinitrophenylhydrazine
Neuenfeldt, Patrícia D.,Drawanz, Bruna B.,Siqueira, Geonir M.,Gomes, Claudia R.B.,Wardell, Solange M.S.V.,Flores, Alex F.C.,Cunico, Wilson
supporting information; experimental part, p. 3106 - 3108 (2010/07/18)
An efficient solvent-free synthesis of thiazolidinones from reaction of mercaptoacetic acid, aldehydes (benzaldehyde and valeraldehyde) or ketones (cyclopentanone and cyclohexanone), and hydrazines (phenylhydrazine and 2,4-dinitrophenylhydrazine) is reported. The compounds were generally characterized by spectroscopic techniques and specifically for 2-cyclohexanyl-3-(N-phenyl)-1,3-thiazolidin-4-one by X-ray crystallography.
A kinetic study of RuIII catalyzed oxidation of galactose and cyclopentanol by potassium bromate in alkaline medium
Srivastava, Sheila,Srivastava, Parul,Chaudhary, Lakshmi,Kumar, Ashish,Singh, Shalini
body text, p. 58 - 62 (2010/05/19)
The kinetics of RuIII catalyzed oxidation of D(+)-galactose (galac) and cyclopentanol (cyclopen) by KBrO3 in alkaline medium using mercuric acetate as a scavenger for Br- ion (galac) as well as co-catalyst (cyclopen), have been studied in the temperature range 30-45°C. The reactions exhibit first-order kinetics with respect to oxidant and catalyst while zero-order kinetics with respect to substrate was observed in case of both galactose and cyclopentanol. For cyclopentanol, a positive effect on the rate of reaction were observed on successive addition of [Hg(OAc)2] and [Cl-] whereas [OH-] exhibited an inverse fractional order. In case of galactose, [OH-] and [Hg(OAc)2] have no effect on the reaction velocity. A positive fractional order in acetic acid concentration (AcOH) and negligible effect of ionic strength of the medium were observed. The reactive species of RuIII in alkaline medium is [RuCl2(H2O)3(OH)] (galac) and [RuCl 3(H2O)2OH]-1 (cyclopen) under the experimental pH range. A suitable mechanism in conformity with the kinetic observation has been proposed. The various activation parameters such as energy of activation (ΔE*), Arrhenius factor (A), entropy of activation (ΔS*) were calculated from the rate measurements at 30, 35, 40 and 45°C. A rate law has been derived on the basis of data obtained.
The application of intramolecular radical cyclizations of acylsilanes in the regiospecific formation of cyclic silyl enol ethers
Huang,Chang,Wang,Tsai
, p. 8983 - 8991 (2007/10/03)
Acylsilanes with terminal α-stannyl bromide or xanthate functionalities are prepared, α-Stannyl radicals generated from these acylsilanes undergo intramolecular cyclizations to give cyclic silyl enol ethers regiospecifically. The radical processes involve radical cyclization, Brook rearrangement, and β-fragmentation in sequence. A tributylstannyl group serves as the radical leaving group. The newly formed σ-bond and π-bond are located between the same two carbon atoms. This approach is limited to the formation of five-membered rings. In another route, ω-bromo-α-phenylsulfonylacylsilanes are synthesized. The radical cyclizations of these α-sulfonylacylsilanes also give cyclic silyl enol ethers. The phenylsulfonyl moiety is the radical leaving group in this system. Furthermore, the newly formed σ-bond and π-bond are located at adjacent positions sharing a single carbon atom. The latter approach is effective for both five- and six-membered ring formation.
A Versatile Synthesis of Four-, Five-, and Six-membered Cyclic Ketones Using Methyl Methylthiomethyl Sulfoxide
Ogura, K.,Yamashita, M.,Suzuki, M.,Furukawa, S.,Tsuchinashi, G.
, p. 1637 - 1642 (2007/10/02)
Cyclization of 1,n-dihaloalkanes with methyl methylthiomethyl sulfoxide in the presence of a base (n-BuLi or KH) gave three-, four-, five-, and six-membered 1-methylsulfinyl-1-methylthiocycloalkanes.These cyclization products were easily converted to the corresponding ketones by acid hydrolysis except 1-methylsulfinyl-1-methylthiocyclopropane which afforded a complicated mixture.The combination of the cyclization with the acidhydrolysis thus provides a new method for synthesizing four-, five-, and six-membered cycloalkanones.Several representative preparations, such as those of substituted cyclobutanones, 3-cyclopentanone, and tetrahydro-4-pyrone are described.
