Rh-Catalyzed Conversion of 3-Diazoindolin-2-imines to 5H-Pyrazino[2,3-b]indoles with Photoluminescent Properties
摘要:
A rhodium-catalyzed reaction between 3-diazoindolin-2-imines and 2H-azirines, followed by treatment with a base, furnishes 5H-pyrazino[2,3-b]indoles in excellent yields. A number of functional groups tolerate the reaction conditions, and the resulting 5H-pyrazino[2,3-b]indoles present strong photoluminecence in solutions, powders, and films.
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 novel [3 + 2] cycloaddition/oxidative aromatization sequence via visible light-induced photoredox catalysis is disclosed. It provides a general synthetic route to 2,4,5-trisubstituted oxazoles from easily accessible 2H-azirines and aldehydes under mild reaction conditions. The potential of this strategy was further demonstrated by the rapid synthesis of a cyclooxygenase-2 inhibitor as well as the
AuBr
<sub>3</sub>
‐Catalyzed Chemoselective Annulation of Isocyanates with 2
<i>H</i>
‐Azirine
作者:Yufeng Wu、Bing Tian、Sina Witzel、Hongming Jin、Xianhai Tian、Matthias Rudolph、Frank Rominger、A. Stephen K. Hashmi
DOI:10.1002/chem.201804765
日期:2019.3.15
cyclization of isocyanates with 2H‐azirine was achieved with AuBr3 as catalyst. This transfer sets the stage for the synthesis of aromatic oxazole‐ureas in a tandem process. The addition of a catalytic amount of phosphite enhances the process enormously. The reaction can also be performed in a one‐pot process using benzoyl azide instead of isocyanate under the same conditions. A detailed study on the role of
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。
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.