ylide intermediate. The effects of the substituents indicate that electron-releasing group favours rearrangement while electron-withdrawing group facilitates insertion. Photolysis of halogenodiazirines in methanol at low temperatures give rise to V-shaped Arrhenius behaviour and the importance of N2 in influencing the reactivity of the singlet halogenocarbene in the matrix is demonstrated.
对位取代的苄基
氯卡宾与
甲醇的插入反应在
甲醇中显示出二阶依赖性,而在
乙二醇中仅表现出一阶依赖性。该结果与一种机理相吻合,其中卡宾通过卡宾在氧孤对上的亲电攻击而插入到醇二聚体或低聚物的O-H键中,从而生成可逆形成的内酯中间体。取代基的作用表明释放电子的基团有利于重排,而吸收电子的基团有利于插入。卤代重氮嗪在
甲醇中在低温下光解会引起V形Arrhenius行为,并且证明了N 2在影响基体中单线态卤代卡宾的反应性方面的重要性。