A study of the sequential Michael addition-ring closure reaction of ethyl acetoacetate with chalcone: influence of quaternary ammonium cations as phase transfer catalysts

Journal of the Brazilian Chemical Society

Regina C. V. Lopes¹  Maria Da Conceição F. De Oliveira¹  Telma L. G. De Lemos¹  Marcos C. De Mattos¹ 

[1] ,Universidade Federal do Ceará Departamento de Química Orgânica e Inorgânica Fortaleza CE ,Brazil

关键词: Phase Transfer Catalysis;    annulation;    Michael reaction;   

DOI  :  10.1590/S0103-50532005000600023

来源: SciELO

【 摘 要 】

The Michael addition of ethyl acetoacetate 1 to chalcone 2 under Solid/Liquid Phase Transfer Catalysis (SL-PTC), solvent free, afforded Michael adduct 3 and an annulated compound 4 in good yield. The cyclic compound 4 was obtained in the majority via an annulation process of the Michael adduct 3. The proportion of 4 in the ratio of 3/4 was dependant on the structure of the quaternary ammonium cation. The results were interpreted on the basis of the organophilicity and accessibility of the catalysts as well as by invoking a 6-membered ring transition state for the formation of 4 due to the chelation level with Q+.

【 授权许可】

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