Reductive activation of arenes 22. Reactions of the terephthalonitrile radical anion and dianion with α,ω-dibromoalkanes. New evidence for the charge transfer complex as a key intermediate in the reactions of the dianion
作者:E. V. Panteleeva、M. Yu. Lukyanova、L. M. Pokrovsky、V. D. Shteingarts
DOI:10.1007/s11172-007-0168-z
日期:2007.6
suggest that reactions of the dianion with intermediate 4-(ω-bromoalkyl)benzonitriles proceed more rapidly than those with the starting α,ω-dibromoalkanes. This was confirmed by competitive reactions of the dianion with 4-(ω-bromoalkyl)benzonitriles and the corresponding alkyl bromides. To explain such a ratio of the reaction rates, a mechanism was proposed for the reaction of the dianion with 4-(ω-
对苯二甲腈自由基阴离子与 α,ω-二溴烷烃 Br(CH2)nBr (n = 3–5) 反应的主要产物是 4-(ω-溴烷基) 苄腈。对苯二甲腈二阴离子的类似反应主要产生 α,ω-双(4-氰基苯基)烷烃。这两种转化都是方便的一步途径,否则不易获得化合物,这些化合物作为多功能构建块很有价值。烷基化的结果表明,二价阴离子与中间体 4-(ω-溴烷基)苄腈的反应比与起始 α,ω-二溴烷烃的反应进行得更快。这通过二价阴离子与 4-(ω-溴烷基) 苄腈和相应的烷基溴的竞争反应得到证实。为了解释反应速率的这种比率,提出了二价阴离子与 4-(ω-溴代烷基)苄腈反应的机理。根据这种机制,电荷转移复合物是关键的反应中间体。