Friedel–Crafts reactions in ionic liquids: the counter-ion effect on the dealkylation and acylation of methyl dehydroabietate
作者:Carlos Baleizão、Natércia Pires、Bárbara Gigante、Maria João Marcelo Curto
DOI:10.1016/j.tetlet.2004.03.185
日期:2004.5
Ionic liquids with different counter-ion and alkyl substitutes were tested as solvents in the dealkylation and acylation of methyl dehydroabietate, a useful and inexpensive building block for the synthesis of higher diterpenes derivatives. Ionic liquids with halogen counter-ions are very active in both reactions with high rate constant and conversion, avoiding the use of the conventional solvents (benzene
具有不同抗衡离子和烷基取代基的离子液体在脱氢松香酸甲酯的脱烷基和酰化反应中作为溶剂进行了测试,这是合成高级二萜衍生物的有用且廉价的基础。带有卤素抗衡离子的离子液体在两个反应中都具有很高的速率常数和转化率,因此非常活泼,避免了在这些反应中使用常规溶剂(苯和二硫化碳)。在脱烷基反应中,抗衡离子从卤素到四氟硼酸酯的变化对立构选择性具有显着影响,显示了抗衡离子在反应过程中的重要性。