Halofluorination of Alkenes Using Dilute Hydrofluoric Acid
作者:Manabu Kuroboshi、Tamejiro Hiyama
DOI:10.1246/bcsj.68.1799
日期:1995.7
Iodofluorination of alkenes was achieved with N-iodosuccinimide, potassium hydrogendifluoride, and 1 M hydrofluoric acid using tetrabutylammonium fluoride as a phase-transfer catalyst. The active fluorinating reagent was shown to be tetrabutylammonium dihydrogentrifluoride by preparing the salt in a different way and by effecting the same transformation under anhydrous conditions. Bromofluorination
使用四丁基氟化铵作为相转移催化剂,用 N-碘代琥珀酰亚胺、二氟化氢钾和 1 M 氢氟酸实现烯烃的碘氟化。通过以不同的方式制备盐并在无水条件下进行相同的转化,活性氟化试剂显示为四丁基二氟化氢铵。烯烃的溴氟化也使用 1,3-二溴-5,5-二甲基乙内酰脲进行。用 DBU 处理 I-F 加合物可立体定向地提供氟烯烃。
Selective catalyzed-rearrangement of terminal epoxides to methyl ketones
作者:J. Prandi、J.L. Namy、G. Menoret、H.B. Kagan
DOI:10.1016/0022-328x(85)87389-7
日期:1985.4
Terminal epoxides of the type have been selectively converted into methyl ketones by various catalysts. Some lanthanide derivatives, MnI2, and Co2(CO)8 gave the best results. The rearrangement of internal epoxides into ketones is much slower, allowing specific transformation of terminal epoxides. The scope of the reaction and tentative mechanisms are discussed.
‘Metal Ion Electrophilic Catalysis’ in Ring-Opening Reactions of 1,2-Epoxides by Metal Halides in Ionic Liquids
作者:Dario Landini、Angelamaria Maia、Cecilia Betti
DOI:10.1055/s-2006-941562
日期:2006.6
Metal ion electrophilic catalysis (Li + > Na + K + ) has been found in ring-opening reactions of 1,2-epoxides 1-5 by metal halides MHal in ionic liquids. The results have been rationalized on the basis of a transition state where the cation M + stabilizes the negative charge developing on the oxygen atom of the oxirane ring while favoring the nucleophilic attack at the adjacent carbon by the ion-paired
金属离子亲电催化 (Li + > Na + K + ) 已在离子液体中金属卤化物 MHal 对 1,2-环氧化物 1-5 的开环反应中发现。结果已基于过渡态合理化,其中阳离子 M + 稳定环氧乙烷环氧原子上产生的负电荷,同时有利于离子对阴离子 Hal - 对相邻碳的亲核攻击。