TBAI / TBHP催化的[3 + 2]环加成/氧化/芳构化级联和在线ESI-MS机理研究:吡咯并[2,1- a ]异喹啉和吲哚并[8,7- b ]吲哚的合成†
摘要:
已经开发了一种用于合成吡咯并[2,1- a ]异喹啉和吲哚并[8,7- b ]吲哚的简便的[3 + 2]环加成/氧化/芳构化级联反应。这种串联方法是通过使用叔丁基过氧化氢(TBHP)作为环境友好的化学计量氧化剂,并以无毒碘化四丁基碘化铵(TBAI)和异丙醇作为绿色溶剂的催化作用来实现的。令人欣慰的是,该协议具有高度的通用性,因为多环化合物的构建可以通过容易获得的双极性亲和剂进行定制。只需催化量的TBAI,因为可以就地回收高价亲电子碘(IOH)通过TBHP氧化。此外,首次通过使用ESI-MS / MS在线监测反应来拦截和表征与该级联反应有关的机理方面和推测的中间体。
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。
A general, simple and green process to access pyrrolo[2,1-a]isoquinolines using a KI/TBHP catalytic system
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.
Iodine-Catalyzed 1,3-Dipolar Cycloaddition/Oxidation/Aromatization Cascade with Hydrogen Peroxide as the Terminal Oxidant: General Route to Pyrrolo[2,1-<i>a</i>]isoquinolines
We report a novel molecular iodine-catalyzed 1,3-dipolar cycloaddition/oxidation/aromatization cascade process with hydrogen peroxide as the terminal oxidant for the construction of pyrrolo[2,1-a]isoquinolines. The product pyrrolo[2,1-a]isoquinolines were obtained from reactions between simple, readily available dipolarophiles and tetrahydroisoquinolines in moderate to excellent yields without the need for a metal catalyst.