Study On The Cationic Lanthanide Complex-Catalyzed Reactions Involving 2-hydroxychalcone

Some reactions catalyzed by cationic lanthanide complexes[Ln(CH3CN)9]3+[(AlCl4)3]3-·(CH3CN)using 2-hydroxychalcone as a substrate were studied in this thesis,which is composed of three parts as follows:1.Cationic lanthanide complexes[Ln(CH3CN)9]3+[(AlCl4)3]3-·(CH3CN)served as efficient catalysts for the reaction of 2-hydroxychalcones with 1,4-dithiane-2,5-diol.A series of 2-(2-hydroxyaryl)-3-aroylthiophene compounds were obtained in moderate to high yields.The possible mechanism was discussed,which may involve a radical reaction.2.The reaction of 2-hydroxychalcones with thiophenols or thiols can be efficiently catalyzed by cationic lanthanide complex[Yb(CH3CN)9]3+[(AlCl4)3]3-·(CH3CN).A series of 2-aryl-4-aryl(alkyl)thio-4H-chromene were obtained in moderate to high yields within 5 minutes.3.The transformation of 2-hydroxychalcones to cyclopenta[c]chromenes can be efficiently catalyzed by cationic lanthanide complex[Yb(CH3CN)9]3+[(AlCl4)3]3-·(CH3CN).A free radical mechanism is proposed through a series of control experiments and EPR analysis,and the factors affecting the generation of radicals were discussed.