Oxidative coupling of phenols. Part 6. A study of the role of spin density factors on the product composition in the oxidations of 3,5-dimethylphenol and phenol
作者:David R. Armstrong、Colin Cameron、Derek C. Nonhebel、Peter G. Perkins
DOI:10.1039/p29830000563
日期:——
Oxidations of both 3,5-dimethylphenol and phenol with di-t-butyl peroxide at 140 °C gave as the major product the ortho-ortho-C–C coupled dimer, while oxidations with di-t-butyl peroxyoxalate at room temperature give much more of the ortho-para-C–C dimer. The results are not consistent either with the spin density distribution in the phenoxyl radical intermediates or with steric effects being the major
在140°C下用过氧化二叔丁基对3,5-二甲基苯酚和苯酚进行氧化,得到的主要产物是邻-邻-CC连接的二聚体,而在室温下用过氧草酸二叔丁基酯氧化得到大部分的更多邻-对-C-C二聚体。结果与苯氧基自由基中间体中的自旋密度分布或空间效应是决定产物组成的主要因素不一致。提出了涉及偶合的两个苯氧基自由基优先以“三明治”方式与氧以1,3-关系相互接近。