Department of Chemistry, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan.
Hiroshima University Research Center for Photo-Drug-Delivery Systems (HiU-P-DDS), Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan.
J Org Chem. 2020 Jul 2;85(13):8627-8638. doi: 10.1021/acs.joc.0c01016. Epub 2020 Jun 17.
Alkoxyl radicals play important roles in various fields of chemistry. Understanding their reactivity is essential to applying their chemistry for industrial and biological purposes. Hydrogen-atom transfer and C-C β-scission reactions have been reported from alkoxyl radicals. The ratios of these two processes were investigated using cumyloxyl (CumO) and -butoxyl radicals (-BuO), respectively. However, the products generated from the pair of radicals have not been investigated in detail. In this study, CumO and -BuO were simultaneously generated from the photolysis of -butyl cumyl peroxide to understand the chemical behavior of the pair of radicals by analyzing the products and their distribution. Electron paramagnetic resonance and/or transient absorption spectroscopy analyses of radicals, including CumO and -BuO, provide more information about the radicals generated during the photolysis of -butyl cumyl peroxide. Furthermore, the photoproducts of (3-(-butylperoxy)pentane-3-yl)benzene demonstrated that the ether products were formed in in-cage reactions. The triplet-sensitized reaction induced by acetophenone, which is produced from CumO, clarified that the spin state did not affect the product distribution.
烷氧基自由基在化学的各个领域都扮演着重要的角色。理解它们的反应性对于将其化学性质应用于工业和生物目的至关重要。已有报道称,烷氧基自由基会发生氢原子转移和 C-Cβ 键断裂反应。分别使用枯基过氧自由基(CumO)和叔丁基过氧自由基(-BuO)研究了这两个过程的比例。然而,这对自由基生成的产物尚未进行详细研究。在这项研究中,通过分析产物及其分布,同时从过氧化叔丁基枯基酯的光解中生成 CumO 和 -BuO,以了解这对自由基的化学行为。电子顺磁共振和/或自由基的瞬态吸收光谱分析,包括 CumO 和 -BuO,提供了更多关于过氧化叔丁基枯基酯光解过程中生成的自由基的信息。此外,(3-(-叔丁基过氧)戊烷-3-基)苯的光产物表明,醚产物是在笼内反应中形成的。由 CumO 生成的苯乙酮的三重态敏化反应表明,自旋态不会影响产物分布。