Studies On Mannich Reaction And Palladium-Catalyzed Allylation In Ionic Liquids

Green chemistry, which aims to eliminate the pollution from the cradle, is becoming the hotspot and the foreland in chemical research. The conventional chemical reaction and its related industry are two of those main sources of pollution. Most of waste is originated from volatile organic compounds (VOC). Therefore, it is especially important to find green solvents as alternatives to conventional organic solvents. Fortunately, the recent emerged room temperature ionic liquids (ILs) are promising to solve this problem, due to their unique physical and chemical properties such as non-toxicity, negligible volatility, non-flammability, excellent thermal stability, wide liquid range (-100℃²00℃), the ease of recovery and good ability to dissolve many kinds of organic and inorganic compounds. Furthermore, the polar or ionic character can change the reaction pathway and make the catalyst more active and stable. This made sense in minimizing and eliminating pollution.The application of ILs in two kinds of organic reactions was evaluated in our dissertation.1. Mannich reaction in acidic ionic liquid [bmim]BF4 acting as the catalyst and solventMannich reaction for formaldehyde, aromatic ketone and aliphatic amine hydrochloride was investigated in [bmim]BF4. Reactions can performance smoothly without any proton acids or Lewis acids. After optimization of the reaction, modest yields were obtained and the ionic liquid [bmim]BF₄ could be easily recycled and reused at least five times without obvious loss of its activity. Mannich reaction between aromatic ketone, aromatic aldehyde and aromatic amine also proved to be feasible in [bmim]BF4.2. Allylation of active methylene compounds with cinnamyl alcohol catalyzed by Pd(PPh₃)₄Allylation of active methylene compounds with cinnamyl alcohol catalyzed by Pd (PPh₃)₄ can take place smoothly in both [bmim]BF₄ and [bmim]PF₆, giving good yields of target products. We have investigated several factors, such as kinds of carboxylic acid and RTILs, reaction time, temperature and the amount of loading catalyst, which may have effects on the reaction. Finally, satisfactory yields were obtained through optimizing reaction conditions. Ionic liquids containing palladium catalyst have been recycled up to 5 times without loss of its activity, making this protocol more economical.