A novel iminoxyl radical-promoted dichotomous regioselective 5-exo-trig cyclization onto vinylic halogen/1,2-halogen radical shift sequence is developed for the synthesis of halomethyl isoxazoles/cyclic nitrones using β-halo-β,γ- and γ-halo-γ,δ-unsaturated ketoximes as the substrates and PhI(OAc)2/TEMPO as the oxidation system. DFT calculations reveal that a halogen-bridged three-membered ring transition
开发了一种新的亚
氨基自由基促进的二分体区域选择性5-exo-trig环化到
乙烯基卤素/ 1,2-卤素自由基转移序列上,用于使用β-卤代-β,γ-和γ-卤代合成卤代甲基
异恶唑/环硝酮-γ,δ-不饱和酮
肟为底物,PhI(OAc)2 /
TEMPO为氧化体系。DFT计算表明,卤代桥三元环跃迁态与1,2-Cl- / Br原子移位有关,而1,2-I原子迁移可通过消除/再分配机制加以考虑。指示迁移能力按以下顺序排列:I> Br> Cl。