Study On The Synthesis Of N-N Bond Coupling And Nitrogenous Heterocyclic Compounds Induced By Lanthanide Compounds

The dissertation covers the studies on the reactivity of Lanthanide amides [(Me₃Si)₂N]₃Ln(μ-Cl)Li(THF)₃ in the N-N bond coupling reaction and on the catalytic activity of the lanthanide chlorides in the synthesis of heteocyclic compounds. There are mainly three parts in the dissertation.Firstly, azo and hydrazine derivatives could be obtained in good yields by reaction of primary and secondary aromatic amine with lanthanide amides [(Me₃Si)₂N]₃Ln(μ-Cl)Li(THF)₃ with exposure to air. The electronic and steric effects were examined. The novel N-N coupling reaction for the generation of symmetrical azo and hydrazine derivatives has the advantages of short time, good to excellent yields, and wide generality for the substrates.Secondly, efficient methods for the synthesis of 1, 2-disubstitued benzimidazoles and 2-substitued benzothiazoles catalyzed by lanthanide chlorides under ultrasonic irradiation and solvent-free conditions are described. The electronic and steric effects on the reaction yields were also examined. Broad generality, high yields, economical catalysts, simple operation, solvent-free condition, ambient temperature are the advantages of this methodology.Thirdly, under solvent-free and ultrasonic irradiation conditions,reaction of o-phenylenediamine with ketone catalyzed by the lanthanide chlorides afforded the products of 1H-1,5-benzodiazepine derivatives with the feasures of high yields, simple reaction conditions and green synthetic methodology. In conclusion, a novel and good method of synthesis of azo and hydrazine derivatives through the N-N bond coupling reaction initiated by lanthanide amides [(Me₃Si)₂N]₃Ln(μ-Cl)Li(THF)₃ was obtained. In addition lanthanide chlorides showed high catalytic activities in the synthesis of heterocylic compounds such as benzimidazoles, benzothiazoles and benzodiazepine derivatives.