烷基-取代自由基闭环反应的区位选择性

The regioselectivity of alkyl-substituted radical ring closure addition

5-己烯自由基进攻双键碳原子,形成五元或六元环分子,在有机合成中被广泛地研究。利用ABEEMσπ模型所获得的Fukui函数和广义Fukui函数,分别结合局域硬软酸碱(HSAB)原理,预测烷基取代的5-己烯自由基闭环反应的区位选择性,取得了与实验相一致的结果;并且广义Fukui函数可以作为分子间活性指标,预测反应之间的活性序列,与实验上的速率常数有很好的一致性。

It is interesting in synthetic organic chemistry that the attack of 5-hexenyl radicals on the carbon-carbon double bonds to form five-or six-membered rings.In this paper, the regioselectivities of alkyl-substituted radical ring closure additions were investigated by the Fukui function and the generalized Fukui function combined with the local HSAB principle, and the reactivity descriptors were obtained by the ABEEMσπ model.The results are in agreement with the experimental regioselectivities.Furthermore, the generalized Fukui function that is the descriptor of intermolecular reactivity rationalizes the reactivity sequence of this series of intramolecular reactions and is in line with the experimental reaction rate constants.