(ArNu)^-的奇电子配置和直接光亲核取代

N-哌啶乙酰胺负离子和一系列溴代芳烃在液氨中的光反应导致酰胺α-碳原子的芳基化,但在溴苯中,光产物组成很复杂:35%1,2-二苯乙烷;2%联苯;5%苯和1.5%N-哌啶苯乙酰胺。MO计算结果显示N-哌啶苯乙酰胺阴离子游离基的奇电子主要配置在哌啶基部分。β-裂解和苄基游离基二聚形成的1,2-二苯乙烷成为主要产物。(ArNu)^-奇电子优先分布在稠环部分的奇电子转移给基态的ArX,从而生成亲核取代产物。

Residence of the odd electron of (ArNu)^- and straight photo- nucleophilic substitution

The photostimu lated reaction of N-iperidinyl acetamide anion with a series of chloroarenes in liquid ammonia led to the arylation at α- carbon of the amide. However, a mass photoproduct distribution consisting of 1, 2-diphenylethanne (35%), biphenyl (2%), benzene (5%) and N-ipperdinyl benzoacetamide was observable. In the case of chlorobenzene MO calculation indicated that the odd electron of (PhCH~2COPi)^- might be heavily populated in the piperdinyl portion of the redical anion. Predominant β-scission of (PHCH~2COPi)^- followed by dimerization of benzyl radical gave 1, 3-diphenylethane as the major product. Residence of the odd electron of (ArNu)^- at the polycylic aryl moiety resulted in the electron to transfer ground ArX and formation of the nucleophilic substitution product.