Preparation And Characterization Of Functional Ionic Liquids And Their Widening Application In Organic Synthesis

Ionic liquids (ILs) as environmentally—friendly green reaction media and new catalytic materials, due to their favorable properties such as negligible vapor pressure, non-inflammability, high thermal stability and adjustable physico-chemical properties, have found numerous applications including organic and inorganic synthesis, separation processes, electrochemistry etc. so researching on the new chemical functionality and application area of ILs is very attractive.From this perspective, kinds of functional basic ILs were synthesized and used as catalysts in one-pot three condensations for2-amino-4H-chromenes. Furthermore we synthesized a series of novel disulfonic acid functionalized ILs. Their structures were characterized by using FT-IR and1H-NMR. The details are given as follows:1. Experimental and theoretical investigation of one-pot synthesis of2-amino-4H-chromenes catalyzed by basic-functionalized ILsa simple and environmentally-friendly procedure has been developed for the synthesis of2-amino-4H-chromene derivatives with high yields by using basic-functionalized ILs as catalysts. The [Bmim]OH showed the highest catalytic activities and reusabilities with good to excellent yields of the desired products. This method offers several advantages such as mild conditions, reusability of catalyst, simple experimental procedure. By performing DFT calculations for the reaction mechanism of salicylaldehydes, malononitrile, nitroalkane in the presence of IL [Bmim]OH, the most possible reaction pathway was proposed for the first time. The results indicated that the cation and anion of [Bmim]OH have coordinative effects on this reaction, which lies in that [Bmim]+stabilizes the reactants via intermolecular hydrogen bonds, while OH□deprives proton of two CH acids to strengthen their nucleophilic ability.2. Preparation and characterization of novel bi-sulfonic acid functionalized ILsTo reduce the cost of bi-sulfonic acid functionalized ILs, fifteen ILs have been synthesized by using4,4'-bipyridine, piperazine, pyridine with industrial materials1,4-butane sultone and1,3-propane sulfonate as source in this paper. These novel bi-sulfonic acid functionalized ILs were characterized by FT-IR,1H-NMR to make certain their molecular formulas. Besides, their melting points were determined. The results revealed that the melting points of ILs were related to their structures.