TEMPO-Mediated Aliphatic C–H Oxidation with Oximes and Hydrazones
摘要:
A method for aliphatic C-H bond oxidation of oximes and hydrazones mediated by 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) has been developed, which enables the concise assembly of substituted isoxazole and pyrazole skeletons.
Selectfluor-Bu<sub>4</sub>NI-Mediated C(sp<sup>3</sup>)-H Oxidation in Aqueous Media: Synthesis of Δ<sup>2</sup>-Isoxazolines from Oximes
作者:Di Shi、Hai-Tao Qin、Chen Zhu、Feng Liu
DOI:10.1002/ejoc.201500780
日期:2015.8
C–H bond within a complex molecule through a free-radical pathway is a valuable tool in synthetic chemistry. Herein, we developed an efficient transition-metal-free approach to generate Δ2-isoxazolinesfromoximes by radical-mediated C(sp3)–H oxidation. Investigation of the mechanism suggested that in the presence of Selectfluor and Bu4NI, the homolysis of the in situ formed O–I bond generated an iminoxyl
Building Congested Ketone: Substituted Hantzsch Ester and Nitrile as Alkylation Reagents in Photoredox Catalysis
作者:Wenxin Chen、Zheng Liu、Jiaqi Tian、Jin Li、Jing Ma、Xu Cheng、Guigen Li
DOI:10.1021/jacs.6b06379
日期:2016.9.28
For the first time, 4-alkyl Hantzsch esters were used to construct molecules with all-carbon quaternary centers by visible light-induced photoredox catalysis via transfer alkylation. Up to a 1500 h(-1) turnover frequency was achieved in this reaction. Reactions of 4-alkyl Hantzsch nitriles as tertiary radical donors joined two contiguous all-carbon quaternary centers intermolecularly, and this chemistry
A method for aliphatic C-H bond oxidation of oximes and hydrazones mediated by 2,2,6,6-tetramethylpiperidin-1-oxyl (TEMPO) has been developed, which enables the concise assembly of substituted isoxazole and pyrazole skeletons.
TEMPO-mediated allylic C–H amination with hydrazones
作者:Xu Zhu、Shunsuke Chiba
DOI:10.1039/c4ob00839a
日期:——
TEMPO-mediated reactions of alkenyl hydrazones afforded azaheterocycles via sp3 C–H allylic amination. The transformation is featured by a sequence of remote allylic H-radical shift and allylic homolytic substitution with hydrazone radicals.