The Effect of Hydrogen Bonding on Allylic Alkylation and Isomerization Reactions in Ionic Liquids
作者:James Ross、Jianliang Xiao
DOI:10.1002/chem.200304895
日期:2003.10.17
Neutral allylic alkylation reactions, in which a base is generated in situ and which hence require no external bases, can significantly be retarded when carried out in the ionic liquid 1-butyl-3-methylimidazolium tetrafluoroborate ([bmim][BF(4)]). Evidence suggests that the base or base precursor enters into hydrogen bonding with the imidazolium cation and is thus made less readily available for deprotonation
当在离子液体1-丁基-3-甲基咪唑四氟硼酸酯([bmim] [BF(4)]中进行时,中性烯丙基烷基化反应可显着延迟,在该反应中,碱是就地生成的,因此不需要外部碱。 )。有证据表明,碱或碱前体与咪唑鎓阳离子发生氢键键合,因此较难用于前亲核试剂的去质子化。然而,在能够脱质子的更强碱的存在下,反应进行得很好。尽管离子液体中的氢键结合现象可能对诸如烯丙基烷基化的反应有害,但可以用来抑制不希望的烯丙基异构化。