Controllable Site-Selective Construction of 2- and 4-Substituted Pyrimido[1,2-<i>b</i>]indazole from 3-Aminoindazoles and Ynals
作者:Xiang Liu、Jinlei Zhou、Jiatong Lin、Zemin Zhang、Suying Wu、Qiuxing He、Hua Cao
DOI:10.1021/acs.joc.1c01094
日期:2021.7.2
straightforward and novel controllable site-selective construction of 2- and 4-substituted pyrimido[1,2-b]indazole from 3-aminoindazoles and ynals has been developed. The high regioselectivity of this reaction could be easily switched by converting different catalytic systems. In this way, a series of 2- and 4-substituted pyrimido[1,2-b]indazole derivatives were obtained in moderate to good yields. In addition, the
已经开发出一种由 3-氨基吲唑和 ynals 直接且新颖的可控位点选择性构建 2-和 4-取代的嘧啶并[1,2 -b ]吲唑的方法。该反应的高区域选择性可以通过转换不同的催化体系轻松切换。通过这种方式,以中等至良好的收率获得了一系列2-和4-取代的嘧啶并[1,2- b ]吲唑衍生物。此外,还讨论了本方法制备的化合物3a的光物理性质。
Synthesis of Pyrrolo[2,1,5-<i>cd</i>]indolizine Rings via Visible-Light-Induced Intermolecular [3+2] Cycloaddition of Indolizines and Alkynes
作者:Yu Zhang、Yue Yu、Bing-bing Liang、Yong-yan Pei、Xiang Liu、Hua-gang Yao、Hua Cao
DOI:10.1021/acs.joc.0c01253
日期:2020.8.21
smoothly underwent visible-light-induced intermolecular [3+2] annulations with internal alkynes to afford pyrrolo[2,1,5-cd]indolizine in good to excellent yields with high regioselectivity. Through this cascade reaction, a series of fluoroactive fused indolizines with a large π-system were conveniently synthesized. The usage of visiblelight as energy source with air as a stoichiometric oxidant under
一系列吲哚并嗪通过内部炔烃顺利地进行了可见光诱导的分子间[3 + 2]环空拆分,从而以良好的产率和良好的区域选择性提供了吡咯并[2,1,5- cd ]吲哚并嗪。通过该级联反应,方便地合成了具有大π系统的一系列含氟稠合吲哚嗪。在简单条件下使用可见光作为能源,以空气作为化学计量的氧化剂,使该过程具有吸引力和实用性。
Controllable Site-Selective Construction of 4- and 5-Hydroxyalkyl-Substituted Imidazoles from Amidines, Ynals, and Water
作者:Wei Liu、Jiaming He、Xiang Liu、Yue Yu、Yongyan Pei、Baofu Zhu、Hua Cao
DOI:10.1021/acs.joc.0c01715
日期:2020.12.4
site-selective pathways to construct 4- and 5-hydroxyalkyl-substituted imidazoles through a three-component reaction of amidines, ynals, and water has been documented. Particularly, the high regioselectivity of the reaction was simply switched by changing the additives. In addition, further 18O-labeled experiments to probe a plausible mechanism and the gram-scale synthesis were studied.