Diethyl Azodicarboxylate-Promoted Oxidative [3 + 2] Cycloaddition for the Synthesis of Pyrrolo[2,1-<i>a</i>]isoquinolines
作者:Ya-Wen Xu、Jiankun Wang、Guangji Wang、Le Zhen
DOI:10.1021/acs.joc.0c01567
日期:2021.1.1
A novel metal-free protocol for the effective and efficient construction of pyrrolo[2,1-a]isoquinolines via a diethyl azodicarboxylate (DEAD)-promoted oxidative [3 + 2] cycloaddition/aromatization tandem reaction is described. Instead of the reported two-component oxidation systems, DEAD, as the sole oxidant, could smoothly transfer the tertiary amines to azomethine ylides via oxidation-deprotonation
描述了一种新型的无金属方案,可通过偶氮二羧酸二乙酯(DEAD)促进的氧化[3 + 2]环加成/芳构化串联反应有效和高效地构建吡咯并[2,1- a ]异喹啉。代替已报道的二组分氧化系统,DEAD作为唯一的氧化剂,可以通过氧化-去质子串联过程将叔胺平稳地转移至偶氮甲亚胺。反应在较宽的底物范围内进行,从而产生中等至良好的分离产率的产物。
作者:Zhiyu Xie、Fei Li、Liangfeng Niu、Hongbing Li、Jincai Zheng、Ruijing Han、Zhiyu Ju、Shanshan Li、Dandan Li
DOI:10.1039/d0ob01403f
日期:——
cycloaddition–aromatization cascade was realized with N-substituted tetrahydroisoquinolines and electron-deficient olefins. Under the mild conditions, the reaction proceeded smoothly and displayed excellent functional group tolerance, affording 5,6-dihydro-pyrrolo[2,1-a]isoquinolines in good to high yields. This protocol exhibits a broad substrate scope to both N-alkyl tetrahydroisoquinolines and dipolarophile
用N-取代的四氢异喹啉和缺电子烯烃实现了高效且环保的CuBr/NHPI共催化好氧氧化[3 + 2]环加成-芳构化级联。在温和条件下,反应顺利进行,并表现出优异的官能团耐受性,以良好至高收率得到5,6-二氢-吡咯并[2,1- a ]异喹啉。该协议对N-烷基四氢异喹啉和亲偶极底物都表现出广泛的底物范围。
作者:Chenguang Yu、Yianan Zhang、Shilei Zhang、Hao Li、Wei Wang
DOI:10.1039/c0cc03186k
日期:——
A novel and synthetically efficient Cu(II) catalyzed oxidation-dipolar cycloaddition-aromatization cascade reaction has been developed for a "one-pot" synthesis of biologically important pyrrolo [2, 1-a] isoquinolines.
A novel KI/TBHP-catalyzed 1,3-dipolar cycloaddition/oxidation/aromatization cascade reaction provided a general, efficient and green access to biologically important pyrrolo[2,1-a]isoquinolines.
A ray of sunshine: The title reaction sequence using ethyl 2‐(3,4‐dihydroisoquinolin‐2(1H)‐yl)acetates with a series of electron‐deficient alkenes and alkynes provides rapid and efficient access to pyrrolo[2,1‐a]isoquinolines (see scheme; bpy=2,2′‐bipyridine, EWG=electron‐withdrawing group). The reaction offers a strategically new protocol for the direct and efficient construction of the core structure