Synthesis of Perfluoroalkyl-Substituted Azines via Nucleophilic Substitution of Hydrogen with Perfluoroisopropyl Carbanions
作者:Rafał Loska、Mieczysław Ma̧kosza
DOI:10.1021/jo062254u
日期:2007.2.1
a new protocol for introduction of perfluoroalkyl substituents into azine rings was elaborated via oxidative nucleophilic substitution of hydrogen. It involves three chemical steps: (i) alkylation of azine with p-MeOC6H4CH2Br, (ii) reaction of the resulting salt with fluorinated carbanions generated in situ from HFP and KF, and (iii) N-deprotection and aromatization of the isolated dihydroazine on
通过在适当的溶剂中用固体KF处理全氟丙烯(HFP)原位生成的全氟异丙基碳负离子会添加到N-烷基吡啶鎓,喹啉鎓和其他叠氮盐中,从而生成具有全氟异丙基的合理稳定的N-烷基二氢嗪。在大多数情况下,加成在杂环的2位进行。这些二氢嗪的稳定性取决于N-烷基和嗪环中存在的其他取代基的性质。在与三氟乙酸酐的反应中,它们中最不稳定的被转化为其稳定的C-三氟乙酰基衍生物。的治疗Ñ苄基或ñ - p-甲氧基苄基-2-全氟异丙基二氢嗪与氧化剂如DDQ或硝酸铈(IV)铵导致苄基C-N键断裂,然后氧化环,得到在芳族环中具有全氟异丙基的吡啶或喹啉。基于这些发现,通过氢的氧化亲核取代,拟订了将全氟烷基取代基引入到嗪环中的新方案。它涉及三个化学步骤:(i)用p -MeOC 6 H 4 CH 2使嗪烷基化Br,(ii)所得盐与从HFP和KF原位生成的氟化碳负离子反应,以及(iii)用CAN处理后,分离出的二氢嗪进行N-脱保护和
Remarks on the mechanism of phase-transfer catalyzed carbanion generation in two-phase systems
作者:M. Mąkosza、I. Kryklowa
DOI:10.1016/s0040-4020(99)00215-x
日期:1999.5
vinyl acetate, t-butyl acrylate and benzaldehyde was studied in a two-phase system, chloroform / conc. aqueous NaOH, and in a homogeneous medium. The results support an interfacial mechanism for generation of carbanions and indicate that chloroform is deprotonated by NaOH at the interface.
189. Mechanism of substitution at a saturated carbon atom. Part XXIV. Qualitative survey of nucleophilic substitutions of benzhydryl halides in sulphur dioxide solution
作者:Leslie C. Bateman、Edward D. Hughes、Christopher K. Ingold