Synthesis And Application Of Basic Ionic Liquids In Catalytic Reactions

Basic ionic liquids (BILs) refer to a new class of ionic liquids which contain basic center endowed bythe functionalization of anion or cation of ionic liquids. They have shown many advantages in the organiccatalytic reactions to replace traditional non-environment benign base catalyst systems because their specialproperties such as non-volatiles, less environmental pollution, and structure and property designability. Inrecent years, the related BILs catalysis has become one of the most important research directions in thefield of green chemistry. In this work, we focused our attention on the design and synthesis of thefunctional basic ionic liquids and their applications in organic catalytic reactions. The details are as follows.1. A series of BILs composed of phenol anion and choline or imidazolium cation were synthesizedthrough the one–step method. Their chemical structures were characterized, some physical properties suchas melting point and thermal stability were determined, and the relationship between the structure and itsthermal stability was discussed. The promoting effect of these ionic liquids on Diels–Alder reactions wasexamined and the plausible influence mechanism of these ionic liquids in different types of solvents wasproposed.2. The catalytic performance of some basic ionic liquids on the synthesis of2-amino-4H-chromenederivatives was investigated. The reaction conditions were optimazed, and the results showed that thiscatalytic system has wide substrate torlerance and almost all of the studied reactions can give more than95%isolated yields for the target compounds. In addition, the catalyst could be recycled five times withoutsignificant decrease in activity.3. The application of some BILs in the synthesis of2-amino-4H-benzo[b]pyrans in water was studied.It was found that at ambient temperatreu the target compounds can give good to excellent yields in thepresence of the basic ionic liquids. This catalytical system has high conversion ratio, and the catalyst andthe products are easy to separate. Furthermore, the catalyst could be reused for five times without anysignificant decrease of its catalytic activity.4. The application of some biasic ionic liquids in the one-pot synthsis of Betti bases has beendeveloped under solvent-free condition. It was found that a wide range of Betti Bases with variable functional groups can be synthesized with excellent yield through the reactions among aldehyde,2-naphthol and the secondary amine.