External oxidant-free oxidation/[3+2] cycloaddition/aromatization cascade: electrochemical synthesis of polycyclic N-heterocycles
作者:Qiang Wang、Ting Yuan、Qiang Liu、Yong Xu、Guanqun Xie、Xin Lv、Shujiang Ding、Xiaoxia Wang、Chen Li
DOI:10.1039/c9cc04336e
日期:——
Here, we describe an efficient and environmentally friendly synthesis of polycyclic N-heterocycles under electrochemical external oxidant-free conditions. The extent of the sequential electrochemical oxidativearomatization can be regulated with the assistance of redox mediators.
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。
Dual organic dyes as a pseudo-redox mediation system to promotion of tandem oxidation /[3+2] cycloaddition reactions under visible light
treated with in situ generated azomethine ylides to prepare corresponding products in good to excellent yields. This metal-free method effectively promoted oxidation/[3 + 2] cycloaddition/oxidative/aromatization domino reaction without further oxidant using dual organic dyes as pseudo-redox mediation system. Besides, for most of the products, product precipitate was readily separated from reaction media
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.
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
Visible-light photoredox catalyzed synthesis of pyrroloisoquinolines via organocatalytic oxidation/[3 + 2] cycloaddition/oxidative aromatization reaction cascade with Rose Bengal
作者:Carlos Vila、Jonathan Lau、Magnus Rueping
DOI:10.3762/bjoc.10.122
日期:——
Pyrrolo[2,1-a]isoquinoline alkaloids have been prepared via a visible light photoredox catalyzed oxidation/[3 + 2] cycloaddition/oxidativearomatization cascade using Rose Bengal as an organo-photocatalyst. A variety of pyrroloisoquinolines have been obtained in good yields under mild and metal-free reaction conditions.