(E)-1-Alkyl-4-[2-(alkylsulfonyl)-1-ethenyl]pyridinium Salts: Reaction with Thiol Groups Giving Rise to Chromophoric (E)-1-Alkyl-4-[2-(alkylsulfanyl)-1-ethenyl]pyridinium Salts
作者:Michel Holler、Hong Sig Sin、Antony James、Alain Burger、Denis Tritsch、Jean-François Biellmann
DOI:10.1002/1521-3765(20000602)6:11<2053::aid-chem2053>3.3.co;2-t
日期:2000.6.2
-ethenyl]pyridinium iodide, prepared from the corresponding thioether by reaction with methyl iodide in diethyl ether, underwent isomerization to the E isomer in a first-order reaction in deuterated [D6]DMSO with an activation energy of 14 kcalmol(-1). At pH 7, the (E)-1-methyl-4-[2-(methylsulfonyl)-1-ethenyl]pyridinium iodide (19) reacted specifically with thiols. The reaction of this sulfone with
分两步合成(E)-1-烷基-4- [2-(烷基磺酰基)-1-乙烯基]吡啶鎓盐。这些砜在pH 7.3下稳定,并用硫醇(包括硫尿嘧啶)进行了亲核乙烯基取代(S(N)V),得到相应的4-(硫代乙烯基)-吡啶鎓盐。(E)-1-甲基-4- [2-(乙基硫烷基)-1-乙烯基]碘化吡啶鎓的X射线衍射结构表明硫与吡啶鎓环共轭。(Z)-1-甲基-4- [2-(甲基硫烷基)-1-乙烯基]吡啶鎓碘化物,由相应的硫醚与甲基碘化物在乙醚中反应制得,在第一级反应中异构化为E异构体在氘代[D6] DMSO中的活化能为14 kcalmol(-1)。在pH 7时,(E)-1-甲基-4- [2-(甲基磺酰基)-1-乙烯基]碘化吡啶鎓(19)与硫醇发生特异性反应。该砜与谷胱甘肽在pH值为7的TES缓冲液中的反应是二级反应(在30摄氏度时k = 4,100 M(-1)s(-1)),并给出了具有强烈长波长的相应取代产物吸收带(λmaxmax=