photoredox system comprising sodium iodide, triphenyl phosphine, and N,N,N′,N′-tetramethylethylenediamine (TMEDA) that can form a self-assembled tetrameric electron donor–acceptor (EDA) complex with diaryliodonium reagents (DAIRs) and furnish aryl radicals upon visible light irradiation. This practical mode of activation of DAIRs enables arylation of an array of heterocycles under mild conditions to provide
我们报道了一种由碘化钠、三苯基膦和N , N , N ', N'-四甲基乙二胺 (TMEDA) 组成的光氧化还原系统,该系统可以与二芳基碘试剂 (DAIR) 形成自组装的四聚体电子供体-受体 (EDA) 复合物,在可见光照射下提供芳基自由基。这种 DAIR 激活的实用模式能够在温和条件下对一系列杂环进行芳基化,从而以中等至优异的产率提供相应的杂芳基-(杂)芳基组装。包括光物理和 DFT 研究在内的详细机制研究提供了对反应机制的深入了解。
Visible Light‐Induced Imide Alkylation of Azauracils with Aryl Diazoesters
作者:Sudhir Kumar Hota、Sandip Murarka
DOI:10.1002/asia.202301027
日期:2024.2
additive-free visible light-induced N−H functionalization of (aza)uracils with α-diazo esters leading to imide alkylation in good to excellent yields. The reaction proceeds through a N−H insertion in dichloromethane as a solvent, whereas, a photochemical three-component coupling product was obtained upon performing the reaction in cyclic ethers (1,4-dioxane, THF) as a solvent.
Photoexcitation electrondonor–acceptor (EDA) complexes provide an effective approach to produce radicals under mild conditions, while the catalytic version of EDA complex photoactivation remains scarce. Herein, we report a visible-light-induced organophotocatalytic pathway for the cyanoalkylation of azauracils using inexpensive and readily available 1,4-diazabicyclo[2.2.2]octane (DABCO) as a catalytic electron
We present an electrochemical alkylation of azauracils using N-(acyloxy)phthalimides (NHPI esters) as readily available alkyl radical progenitors under metal- and additive-free conditions. Several azauracils are shown to undergo alkylation with an array of NHPI esters (1°, 2°, 3°, and sterically congested), providing the desired products in good to excellent yields. This operationally simple method
A photo‐induced Minisci–type cyanoalkylation of azauracils was developed under metal‐free and base‐free conditions. Readily available cyclobutanone oxime esters were used as the cyanoalkylating reagents via C−C bond cleavage to generate the γ‐cyanoalkyl azauracil derivatives in good to moderate yields. The introduced cyano group can be easily converted into many other functional groups, thus makes current protocol more practical.