that 2 a and 2 b were thermally stable at 300 and 180 °C, respectively. These complexes exhibited unusually high solubility in polar organicsolvents. 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
强路易斯酸空气中稳定的金属茂双(全氟辛烷磺酸盐)S [M(CP)2 ] [OSO 2 C ^ 8 ˚F 17 ] 2 ⋅ Ñ ħ 2 O⋅THF(M = Zr的(2 ⋅3ħ 2 O⋅THF ),M =的Ti(图2b ⋅2ħ 2 O⋅THF))由[M(CP)的反应合成2 ]氯2(M = Zr的(1),M =的Ti(图1b)),与n BuLi和C 8 F 17 SO 3 H(2当量)或与C 8 F 17 SO 3Ag(2当量)。这些配合物的水合物数(n)是可变的,取决于条件从0变为4。与众所周知的茂金属三氟甲磺酸盐相反,这些络合物在露天环境中一年没有变化。热重-差示扫描量热(TG-DSC)分析表明,2和图2b分别为300和180℃,是热稳定的。这些配合物在极性有机溶剂中显示出异常高的溶解度。电导率测量表明,络合物(2a和2b)在CH 3 CN溶液中呈离子离解。X射线分析结果确认为2 a⋅3H
Strong Lewis acid air-stable cationic titanocene perfluoroalkyl(aryl)sulfonate complexes as highly efficient and recyclable catalysts for C–C bond forming reactions
aldimines took place smoothly in aqueous organic solvent to afford β-aminocarbonyl compounds in high yields. The HBF4-catalyzed Mannich-type reaction also proceeded smoothly in water without organic solvent in the presence of a surfactant. A three-component synthesis starting from aldehyde, amine, and silyl enolate was successfully realized by means of a Bronsted acid in aqueous media.
Brønsted acidic ionic liquids of aza-crown ether complex cations: preparation and applications in organic reactions
作者:Chen Cheng、Huanwang Jing
DOI:10.1039/c4ra03061c
日期:——
of an aza-crownether chelated potassium cation and various anions, were designed, synthesized and characterised by FTIR, NMR and mass spectrometry, thermogravimetric differential thermal analysis (TG-DTA) and elemental analysis. These new Brønsted acidic ionic liquids of aza-crownether complex cations (aCBAILs) were applied as catalysts to the Biginelli reaction, Mannich reaction and synthesis of
MgO nanoparticles were prepared by an improved sol–gel technique which appeared to have narrow size distributions. The synthesized magnesium oxide nanoparticles were used as an efficient catalyst in aza-Michael reaction for addition of amines to a series of α,β-unsaturated carbonyl compounds and nitro olefins under solvent-free conditions at room temperature to afford high yields of the β-amino carbonyl and β-nitro amines. The catalyst can be recovered and reused at least five successive runs without loss of activity.