A new method for the synthesis of 1-methylimidazolium trifluoroacetate ([Hmi]Tfa), a protic ionic liquid (PIL), under ultrasonic irradiation has been developed. In addition, the product [Hmi]Tfa was successfully emplo...A new method for the synthesis of 1-methylimidazolium trifluoroacetate ([Hmi]Tfa), a protic ionic liquid (PIL), under ultrasonic irradiation has been developed. In addition, the product [Hmi]Tfa was successfully employed as solvent and catalyst in Biginelli reaction to prepare 3,4-dihydropyrimidinones (DHPMs) in high yield under mild reaction conditions.展开更多
The authors have studied the Diels-Alder reactions between furan derivatives and maleimide derivatives in an ionic liquid and have found that higher reactivity can be obtained in a protic ionic liquid [Mim]Tf2N than i...The authors have studied the Diels-Alder reactions between furan derivatives and maleimide derivatives in an ionic liquid and have found that higher reactivity can be obtained in a protic ionic liquid [Mim]Tf2N than in the conventional organic solvent. Furthermore, in the Diels-Alder reactions of 2- and 2,5-alkylfurans with N-alkylma- leimide, the reactivity increases by extending the alkyl chain length of N-alkylmaleimide. In addition, it was demon- strated that endo-selectivity increases when 2,5-disubstituted furans are used. These results will be explained by comparing the stability of the Diels-Alder adduct with that of the products obtained from the reactions of 2-substituted furans and 2,5-disubstituted furans.展开更多
基金the National Natural Science Foundation of China(21176033,21006007,21203193,21273029)Research Foundation for the Doctoral Program of Higher Education of China(20120042110024)~~
文摘A new method for the synthesis of 1-methylimidazolium trifluoroacetate ([Hmi]Tfa), a protic ionic liquid (PIL), under ultrasonic irradiation has been developed. In addition, the product [Hmi]Tfa was successfully employed as solvent and catalyst in Biginelli reaction to prepare 3,4-dihydropyrimidinones (DHPMs) in high yield under mild reaction conditions.
文摘The authors have studied the Diels-Alder reactions between furan derivatives and maleimide derivatives in an ionic liquid and have found that higher reactivity can be obtained in a protic ionic liquid [Mim]Tf2N than in the conventional organic solvent. Furthermore, in the Diels-Alder reactions of 2- and 2,5-alkylfurans with N-alkylma- leimide, the reactivity increases by extending the alkyl chain length of N-alkylmaleimide. In addition, it was demon- strated that endo-selectivity increases when 2,5-disubstituted furans are used. These results will be explained by comparing the stability of the Diels-Alder adduct with that of the products obtained from the reactions of 2-substituted furans and 2,5-disubstituted furans.
