57956-40-8Relevant articles and documents
Strong Lewis acids of air-stable metallocene bis(perfluorooctanesulfonate)s as high-efficiency catalysts for carbonyl-group transformation reactions
Qiu, Renhua,Xu, Xinhua,Peng, Lifeng,Zhao, Yalei,Li, Ningbo,Yin, Shuangfeng
, p. 6172 - 6182 (2012)
Strong Lewis acids of air-stable metallocene bis(perfluorooctanesulfonate)s [M(Cp)2][OSO2C8F17] 2·nH2O·THF (M=Zr (2 a·3 H 2O·THF), M=Ti (2 b·2 H2O·THF)) were synthesized by the reaction of [M(Cp)2]Cl2 (M=Zr (1 a), M=Ti (1 b)) with nBuLi and C8F17SO3H (2 equiv) or with C8F17SO3Ag (2 equiv). The hydrate numbers (n) of these complexes were variable, changing from 0 to 4 depending on conditions. In contrast to well-known metallocene triflates, these complexes suffered no change in open air for a year. thermogravimetry-differential scanning calorimetry (TG-DSC) analysis showed that 2 a and 2 b were thermally stable at 300 and 180 °C, respectively. These complexes exhibited unusually high solubility in polar organic solvents. Conductivity measurement showed that the complexes (2 a and 2 b) were ionic dissociation in CH3CN solution. X-ray analysis result confirmed 2 a·3 H2O·THF was a cationic organometallic Lewis acid. UV/Vis spectra showed a significant red shift due to the strong complex formation between 10-methylacridone and 2 a. Fluorescence spectra showed that the Lewis acidity of 2 a fell between those of Sc3+ (λem=474 nm) and Fe3+ (λem=478 nm). ESR spectra showed the Lewis acidity of 2 a (0.91 eV) was at the same level as that of Sc3+ (1.00 eV) and Y 3+ (0.85 eV), while the Lewis acidity of 2 b (1.06 eV) was larger than that of Sc3+ (1.00 eV) and Y3+ (0.85 eV). They showed high catalytic ability in carbonyl-compound transformation reactions, such as the Mannich reaction, the Mukaiyama aldol reaction, allylation of aldehydes, the Friedel-Crafts acylation of alkyl aromatic ethers, and cyclotrimerization of ketones. Moreover, the complexes possessed good reusability. On account of their excellent catalytic efficiency, stability, and reusability, the complexes will find broad catalytic applications in organic synthesis. Copyright
9-azanoradamantane N—oxyl compound and method for producing same, and organic oxidation catalyst and method for oxidizing alcohols using 9-azanoradamantane N—oxyl compound
-
Page/Page column 31-32, (2015/09/23)
An organocatalyst for oxidizing alcohols in which a primary alcohol is selectively oxidized in a polyol substrate having a plurality of alcohols under environmentally-friendly conditions. The organic oxidation catalyst has an oxygen atom bonded to a nitrogen atom of an azanoradamantane skeleton and at least one alkyl group at positions 1 and 5. The oxidation catalyst has higher activity than TEMPO, which is an existing oxidation catalyst, in the selective oxidation reaction of primary alcohols, and better selectivity than AZADO and 1-Me-AZADO. This DMN-AZADO can be applied to the selective oxidation reaction of primary alcohols that contributes to shortening the synthesizing process for pharmaceuticals, pharmaceutical raw materials, agricultural chemicals, cosmetics, organic materials, and other such high value-added organic compounds.
Mukaiyama aldol reaction of trimethylsilyl enolate with aldehyde catalyzed by CuI
Kalita, Hima Rani,Borah, Arun Jyoti,Phukan, Prodeep
, p. 289 - 292 (2013/05/22)
Cuprous iodide has been found to be a very effective catalyst for Mukaiyama aldol reaction of trimethylsilyl ketene acetal with aldehydes. The new catalytic system promotes efficiently the Mukaiyama aldol reaction in DMF to produce corresponding β-hydroxy carbonyl compounds in high yield.
