A novel strategy involving visible-light-induced functionalization of alkenes for the synthesis of substituted aziridines was developed. The readily prepared N-protected 1-aminopyridinium salts were used for the generation of N-centered radicals. This approach allowed the synthesis of aziridines bearing various functional groups with excellent diastereoselectivity under mild conditions. Moreover, this
Micellar Catalysis: Visible‐Light Mediated Imidazo[1,2‐
<i>a</i>
]pyridine C—H Amination with
<i>N</i>
‐Aminopyridinium Salt Accelerated by Surfactant in Water
A light-promoted metal-free protocol for the amination of imidazo[1,2-a]pyridines with N-aminopyridinium salt by the assistance of surfactants in water was reported, charactering mild and environmentally benign conditions, as well as great functional group tolerance. Micelles with negatively charged polar surface and hydrophobic core formed from sodium dodecyl sulfate serve as an ideal medium for visible-light
报道了在水中表面活性剂的辅助下咪唑并[1,2- a ]吡啶与N-氨基吡啶鎓盐胺化的光促进无金属方案,具有温和和环境友好的条件,以及良好的官能团耐受性. 具有带负电荷的极性表面和由十二烷基硫酸钠形成的疏水核的胶束是可见光介导的阳离子吡啶盐和咪唑并[1,2- a ]吡啶在水相中发生自由基反应的理想介质。带正电荷的N-氨基吡啶鎓与带负电荷的胶束表面之间的静电相互作用在该方法中具有重要意义。
Direct Vicinal Disubstitution of Diaryliodonium Salts by Pyridine<i>N</i>-oxides and<i>N</i>-amidates by a 1,3-Radical Rearrangement
Paired off: The title reaction leads to a series of o‐pyridinium phenols (1) and anilines (2). The experimental and computational studies indicate that the key step involves homolytic cleavage to give a radical pair, which undergoes solvent‐cage recombination to give the product.
A novel visible-light-induced aza-pinacol rearrangement was developed for the first time. In this approach, the addition of the N-centered radical to the C═C bond of alkylidenecyclopropanes delivers a variety of cyclobutanimines and γ-butyrolactones, with all-carbon quaternary centers via the ringexpansion of the cyclopropyl group, in moderate to good yields under mild reaction conditions.
Selective 1,2‐Aminoisothiocyanation of 1,3‐Dienes Under Visible‐Light Photoredox Catalysis
作者:Weisi Guo、Qian Wang、Jieping Zhu
DOI:10.1002/anie.202014518
日期:2021.2.19
N‐aminopyridinium salts and TMSNCS affords 1,2‐aminoisothiocyanation products in a highly chemo‐ and regio‐selective manner under mild photoredox catalytic conditions. Mechanistic studies indicate that the facile isomerization of allyl thiocyanates to allyl isothiocyanates under photocatalytic conditions is responsible for the selective formation of the observed products. The mild isomerization protocol