Side-Chain Fragmentation of Arylalkanol Radical Cations. Carbon−Carbon and Carbon−Hydrogen Bond Cleavage and the Role of α- and β-OH Groups
作者:Enrico Baciocchi、Massimo Bietti、Lorenza Putignani、Steen Steenken
DOI:10.1021/ja954236s
日期:1996.1.1
hoxypropane (1), only deprotonation of the radical cation is observed. In contrast, removing the ring methoxy group leads to exclusive C−C bond cleavage in the radical cation. Replacing the side-chain β-OMe by β-OH, the radical cation undergoes both C−C and C−H bond cleavage, with both pathways being base catalyzed. C−C bond breaking in the radical cation is also enhanced by an α-OH group, as shown
12-钨钴酸(III)钾(缩写为Co(III)W)对许多1-芳基丙醇、1,2-二芳基乙醇和它们的一些甲基醚进行单电子氧化的产物分析和动力学研究进行了醋酸水溶液,并通过脉冲辐解实验进行了补充。氧化通过自由基阳离子发生,这些阳离子经历涉及 Cα-H 和/或 Cα-Cβ 键的侧链断裂。对于 1-(4-甲氧基苯基)-2-甲氧基丙烷 (1),仅观察到自由基阳离子的去质子化。相反,去除环甲氧基会导致自由基阳离子中的 C-C 键断裂。用 β-OH 代替侧链 β-OMe,自由基阳离子经历 C-C 和 C-H 键裂解,两种途径都被碱催化。α-OH 基团也增强了自由基阳离子中的 C-C 键断裂,如 1-(4-甲氧基苯基)-2,2-二甲基-1-丙醇 (7) 所示,该途径也是碱催化的,是唯一观察到的途径。有趣的是,α-和β-OH基团表现出...