已经开发了一种原子经济和阶梯经济协议,以在可见光照射下通过氧化还原介导系统合成一些新的生物活性吡咯并[2,1- a ]异喹啉生物碱。各种各样的双键和三键,作为偶极体,用原位生成的偶氮甲碱叶立德处理以制备相应的产品,产率很好。这种不含金属的方法使用双有机染料作为假氧化还原介导系统,有效地促进了氧化/[3+2]环加成/氧化/芳构化多米诺反应,无需进一步的氧化剂。此外,对于大多数产物,产物沉淀很容易从反应介质中分离出来。据我们所知,这是双染料作为伪氧化还原介导系统的第一份报告.
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。
Chlorophyll-catalyzed tandem oxidation /[3+2] cycloaddition reactions toward the construction of pyrrolo[2,1-a]isoquinolines under visible light
作者:Mehdi Koohgard、Mona Hosseini-Sarvari
DOI:10.1016/j.jphotochem.2020.112877
日期:2021.1
Chlorophyll as a green, cheap, and affordable natural pigment was used in the one-pot synthesis of pyrrolo[2,1-a]isoquinoline scaffold under visiblelight. This photocatalytic approach has handled oxidation/[3 + 2] cycloaddition/aromatization cascade reaction usingair as the final oxidant. Under this condition, a vast variety of N-substituted tetrahydroisoquinolines were treated with dipolarophiles
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