General Synthesis of Tri-Carbo-Substituted <i>N</i><sup>2</sup>-Aryl-1,2,3-triazoles <i>via</i> Cu-Catalyzed Annulation of Azirines with Aryldiazonium Salts
作者:Fang-Fang Feng、Jun-Kuan Li、Xuan-Yu Liu、Fa-Guang Zhang、Chi Wai Cheung、Jun-An Ma
DOI:10.1021/acs.joc.0c01433
日期:2020.8.21
The general synthesis of fully substituted N2-aryl-1,2,3-triazoles is hitherto challenging compared with that of the N1-aryl counterparts. Herein, we describe a Cu-catalyzed annulation reaction of azirines and aryldiazonium salts. This regiospecific method allows access to a broad spectrum of tri-carbo N2-aryl-1,2,3-triazoles substituted with diverse aryl and alkyl moieties. Its utility is highlighted
Ruthenium-Catalyzed [3 + 2] Cycloaddition of 2<i>H</i>-Azirines with Alkynes: Access to Polysubstituted Pyrroles
作者:Tengfei Li、Hao Yan、Xincheng Li、Chunxiang Wang、Boshun Wan
DOI:10.1021/acs.joc.6b02322
日期:2016.12.2
A ruthenium-catalyzed intermolecular [3 + 2] cycloaddition of 2H-azirines and activated alkynes is reported, which provides polysubstituted pyrroles in moderate to good yields. This approach features a C–N bond cleavage of 2H-azirines by a ruthenium catalyst. The results of this study would provide a complementary method to synthesize polysubstituted pyrroles from the known 2H-azirine approaches and
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。
Visible-Light-Induced Formal [3+2] Cycloaddition for Pyrrole Synthesis under Metal-Free Conditions
A photocatalytic formal [3+2] cycloaddition of 2H‐azirines with alkynes has been achieved under irradiation by visiblelight in the presence of organic dye photocatalysts. This transformation provides efficient access to highly functionalized pyrroles in good yields and has been applied to the synthesis of drug analogues. A primary trial of photocascade catalysis merging energy transfer and redox neutral
在有机染料光催化剂的存在下,在可见光照射下,已实现了2 H H叠氮基与炔烃的光催化形式[3 + 2]环加成反应。这种转化提供了以高收率高效获得高度官能化吡咯的途径,并已应用于药物类似物的合成。光级联催化合并能量转移和氧化还原中性反应的初步试验显示是成功的。
[3 + 2]-Cycloaddition of 2<i>H</i>-Azirines with Nitrosoarenes: Visible-Light-Promoted Synthesis of 2,5-Dihydro-1,2,4-oxadiazoles
A formal [3 + 2]-cycloaddition reaction of 2H-azirines with nitrosoarenes has been achieved under irradiation by visible light with the assistance of organic dye photoredox catalyst. This method utilizes nitrosoarenes as efficient radical acceptors and provides a green and powerful method for a series of biologically important 1,2,4-oxadiazole derivatives in moderate to good yields.