<scp>Visible‐Light‐Promoted</scp>
[3 + 2] Cycloaddition of
<scp>
2
<i>H</i>
‐Azirines
</scp>
with Quinones: Access to Substituted Benzo[
<i>f</i>
]isoindole‐4,9‐diones
作者:Lijia Wang、Chuang Liu、Lei Li、Xin Wang、Ran Sun、Ming‐Dong Zhou、He Wang
DOI:10.1002/cjoc.202100728
日期:2022.3.15
A visible-light-promoteded [3 + 2] cycloadditionreaction of 2H-azirines with quinones has been developed under mild reaction conditions. The reaction provides a general and efficient strategy for the synthesis of the benzo[f]isoindole-4,9-diones scaffold via a tandem [3 + 2] cyclization/oxidative aromatization with molecular oxygen. Furthermore, preliminary studies for photocatalytic properties show
在温和的反应条件下,已开发出一种可见光促进的 2 H-氮丙啶与醌的 [3 + 2] 环加成反应。该反应为通过分子氧的串联[3 + 2]环化/氧化芳构化合成苯并[ f ]异吲哚-4,9-二酮骨架提供了一种通用且有效的策略。此外,对光催化性能的初步研究表明,苯并[ f ]isoindole-4,9-diones 3 可用作多种有机转化的光催化剂。
Modular 2,3-diaryl-2<i>H</i>-azirine synthesis from ketoxime acetates <i>via</i> Cs<sub>2</sub>CO<sub>3</sub>-mediated cyclization
A modular 2H-azirine synthesis from ketoximeacetates via Cs2CO3-mediated cyclization has been developed. The reaction utilizes easily available starting materials and provides a general synthetic route to 2,3-diaryl-2H-azirines in good to excellent yields under mild conditions, which is complementary to the conventional approaches for the synthesis of 2H-azirines. A gram-scale reaction was performed
已经开发了由乙酸酮肟通过Cs 2 CO 3介导的环化合成的模块化2 H-叠氮基。该反应利用容易获得的原料,并在温和条件下以良好至优异的产率提供了合成2,3-二芳基-2 H-叠氮基的一般合成路线,这是合成2 H-叠氮基的常规方法的补充。进行了克级反应以证明该合成方法的放大适用性。重要的是,2 H-叠氮基可以有效地转化为各种氮杂杂环。
Copper-Catalyzed Asymmetric Addition of Tertiary Carbon Nucleophiles to 2<i>H</i>-Azirines: Access to Chiral Aziridines with Vicinal Tetrasubstituted Stereocenters
catalytic asymmetric nucleophilic addition of tertiary carbon nucleophiles to 2H-azirines was established in the presence of the chiral N,N′-dioxide/CuII complex. Various chiral aziridines with vicinaltetrasubstituted stereocenters were obtained in high yields with excellent diastereoselectivities and enantioselectivities. Moreover, on the basis of the control experiments, X-ray structures of the products
在手性N,N'-二氧化物/ Cu II配合物的存在下,将叔碳亲核试剂催化不对称亲核加成到2个H-叠氮基上。高产率地获得具有邻位四取代立体中心的各种手性氮丙啶,其具有非对映选择性和对映选择性。此外,在控制实验,产物的X射线结构和催化剂的基础上,提出了可能的过渡态来解释立体选择性。
Visible light-induced cyclization reactions for the synthesis of 1,2,4-triazolines and 1,2,4-triazoles
novel method for concisely synthesizing1,2,4-triazolines via [3+2] cyclization under visible light is reported. These compounds can be easily converted into 1,2,4-triazoles under basic or photoredox conditions. The application of the 1,2,4-triazoles was also investigated via mild operations.
Radical-initiated diazo-retaining nucleophilic addition reaction of trifluorodiazoethane and diazoacetate with 2H‑azirines
作者:Yue-Ji Chen、Jie Zheng、Jun-An Ma、Fa-Guang Zhang
DOI:10.1016/j.jfluchem.2023.110129
日期:2023.5
A diethylzinc-air system is established to enable an unconventional diazo-retaining nucleophilic addition reaction of trifluorodiazoethane and diazoacetate with 2H-azirines. This transformation converted a broad range of cyclic 2H-azirines to valuable acyclic α-diazo amines in good yields. Further synthetic transformations provide access to β-CF3 amines, β-CF3-enamines, and CF3-oxazolines. Preliminary