topic in green chemistry. Herein, a series of basic ionicliquids (ILs) were investigated as catalysts for the synthesis of vicinal diols via the hydrolysis of cyclic carbonates in order to improve this kind of synthetic process. The effects of the IL structure, the molar ratio of cyclic carbonate to water, and various reaction parameters on the catalytic performance were investigated in detail. It was
在温和的反应条件下开发用于反应的高效,廉价和可循环使用的催化剂是绿色化学中非常有吸引力的主题。在本文中,研究了一系列碱性离子液体(ILs)作为通过环状碳酸酯水解合成邻位二醇的催化剂,以改善这种合成方法。详细研究了IL结构,环状碳酸酯与水的摩尔比以及各种反应参数对催化性能的影响。发现一种简单的无卤两性离子催化剂1,3-二甲基咪唑-2-羧酸盐具有很高的活性(时空产率为1086 h -1),并具有优异的选择性,可用于制备乙二醇。碳酸亚乙酯的水解。该催化剂可以重复使用六次而不会明显降低催化活性。同样,它适用于多种环状碳酸酯,以高产率和高选择性生产它们相应的邻位二醇。根据实验结果,核磁共振光谱和理论计算,提出了一种可能的催化循环方法。该反应方案为化学合成替代传统的碱性或碱性ILs开辟了新的可能性。
A Novel and Green Method for the Synthesis of Ionic Liquids Using the Corresponding Acidic Ionic Liquid Precursors and Dialkyl Carbonate
作者:Wenjun Xiao、Xiaoxing Wang、Qin Chen、Tinghua Wu、Ying Wu、Lizong Dai、Chunshan Song
DOI:10.1246/cl.2010.1112
日期:2010.10.5
A novel and green method for the synthesis of dialkylimidazolium ionic liquids (ILs) has been developed. It was through a one-step alkylation of dialkyl carbonate with the corresponding acidic ionic liquid precursors (AILPs) prepared from the neutralization of imidazole derivatives with acids.
METHOD FOR THE PRODUCTION OF DISUBSTITUTED IMIDAZOLIUM SALTS
申请人:Siemer Michael
公开号:US20100249432A1
公开(公告)日:2010-09-30
Process for preparing 1,3-disubstituted imidazolium salts of the formula I
where
R1 and R3 are each, independently of one another, an organic radical having from 1 to 20 carbon atoms,
R2, R4 and R5 are each, independently of one another, an H atom or an organic radical having from 1 to 20 carbon atoms,
X is the anion of a hydrogen acid having a pK
a
of at least 2 (measured at 25° C., 1 bar in water or dimethyl sulfoxide) and
n is 1, 2 or 3,
wherein
a) an α-dicarbonyl compound, an aldehyde, an amine and the hydrogen acid of the anion X
−
are reacted with one another and
b) the reaction is carried out in water, a solvent which is miscible with water or a mixture thereof.
A broad and simple method permitted halide ions in quaternary heteroaromatic and ammonium salts to be exchanged for a variety of anions using an anion exchange resin (A− form) in non-aqueous media. The anion loading of the AER (OH− form) was examined using two different anion sources, acids or ammonium salts, and changing the polarity of the solvents. The AER (A− form) method in organic solvents was
Ionicliquids were prepared via hydrothermal decarboxylation of zwitterionic imidazolium compounds derived from amino acids and carbohydrate related dicarbonyl compounds. Two of these ionicliquids were used successfully as solvents in the Heckreaction and for the dissolution of cellulose.