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

Some reactions catalyzed by cationic lanthanide complexes[Ln（CH₃CN）₉]³⁺[（Al Cl₄）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⁺[（Al Cl₄）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 efficientlycatalyzedbycationiclanthanidecomplex[Yb（CH₃CN）₉]³⁺[（Al Cl₄）₃]^3–·（CH₃CN）.Aseriesof2-aryl-4-aryl（alkyl）thio-4H-chromene were obtained in moderate to high yields within5 minutes.3.The transformation of 2-hydroxychalcones to cyclopenta[c]chromenes can be efficientlycatalyzedbycationiclanthanidecomplex[Yb（CH₃CN）₉]³⁺[（Al Cl₄）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.