Synthesis Of Dendritic Amines And Guanidinium Ionic Liquids And Their Application In Henry Reaction

The Henry reaction is one of the useful C-C bond forming reaction in orgnic synthesis. The resulting product is aβ-nitroalcohols which is a valuable intermediate in synthetic organic chemistry. In decades, the study of catalysts of Henry reaction is very popular. Many catalysts have been developed in Henry reaction, such as inorganic bases, orgnic bases, polymers, enzyme, ionic liquids and so on. In this dissertation, we designed and synthesized two kinds of recycleable catalysts. One is dendritic amine catalysts, another is guanidinium ionic liquids. We also studied their catalyzing performance in Henry reaction. We emphasized on studying their catalysis performance of recycling.1. Using the G0～G2 polyphenyl ether as the carrier, we synthesized three denrditic piperidine catalysts which were characterized by 1H NMR,13C NMR and Ms. We examed the performance of the resulting catalysts in Henry reaction for aromatic aldehyde in different solvents. The G0～G1 catalysts show best performance when we carried the reaction in nitromethane. It is pity that the performance of catalysts dropped down when the generation number of dendritic catalysts increased. To our surprise, if the reaction is catalyzed in aqueous, the activity of catalysts can be retained when the generation number of the catalysts increased. And we found the G2 dendritic catalyst can be reused for 5 times after simplely separated without obviously loss of activity.2. Four kinds of guanidinium halide ionic liquids were syhthesized from 1,1,3,3-tetramethylguanidine and alkyl halide. And ten kinds of guanidinium ionic liquids with different anions were obtained by methathesis reaction of the guanidinium halide ionic liquids. All of the above mentioned compounds were characterized by 1H NMR,13C NMR and Ms. The catalytic performance of these guanidinium ILs with various cations and anions were investigated. The results showed that [BTMG][OAc] provided the best yield of 93% in Henry reaction of aromatic aldehyde. At last, the catalysts could be easily separated and reused 6 times without significant loss of activity.