Rhodium-catalysed synthesis of fused pyrimidine derivatives employing N-sulfonyl-1,2,3-triazoles as a 1-aza-[4C] synthon
作者:Ze-Feng Xu、Yuehui An、Yidian Chen、Shengguo Duan
DOI:10.1016/j.tetlet.2019.06.023
日期:2019.7
A new synthetic application of N-sulfonyl-1,2,3-triazoles acting as a 1-aza-[4C] synthon via the 1,2-shift reaction of an α-imine rhodium carbene was developed for the synthesis of fused pyrimidine derivatives. The high reactivity of the strained three-membered 2H-azirine ring facilitated the unusual cyclization of electron-deficient dienes with electron-deficient dienophiles. The compatibility was
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
Zinc-Enabled Annulation of Trifluorodiazoethane with 2<i>H</i>-Azirines to Construct Trifluoromethyl Pyrazolines, Pyrazoles, and Pyridazines
作者:Yue-Ji Chen、Fa-Guang Zhang、Jun-An Ma
DOI:10.1021/acs.orglett.1c02139
日期:2021.8.6
involves two [3 + 2] cycloaddition steps and one dinitrogen extrusion process in one pot, thus giving a broad array of 3-trifluoromethyl pyrazolines in good yields with excellent diastereoselectivities. Further transformations provide facile access to 3-trifluoromethyl pyrazoles and 3,5-ditrifluoromethyl pyridazines with good efficiency.
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。