Temperature Ionic Liquids In Palladium Catalyzed Allylic Substitution,

The conventional chemical reaction and related industry are two of the main sources of pollution at present. Most of waste is originated from volatile organic compounds (VOCs) used in chemical reactions. Room temperature ionic liquids (RTILs) have been accepted as green alternatives to conventional organic solvents, 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 good ability to dissolve many kinds of organic and inorganic compounds and the ease of recovery. Furthermore, the polar or ionic character can change the reaction pathway and make the catalyst more active and stable. The application of ionic liquids made sense in minimizing and eliminating pollution.The application of RTILs in Palladium-catalyzed allylation reaction was evaluated in this dissertation. We have investigated several factors, such as the kind of RTILs, the kind and amount of catalyst, the ratio of substrates, reaction time and temperature, which may have effects on the reaction. Moreover, allylation reaction of several different active methylene compounds and the reusability of ionic liquid/catalyst have been investigated. Allylation of active methylene compounds with allylic alcohol catalyzed by Pd catalyst could take place in [bmim]Cl, [bmim][BF4] and [bmim][PF₆]. Though with up to moderate yields of target products, Pd(OAc)₂ could catalyze allylation reaction at room temperature, ionic liquid/catalyst could be easily recycled and reused at least five times without obvious loss of activity in both acid and alkaline condition, which was benign to environment. Besides, its simple work-up procedure could embody the advantage of ionic liquids.