我们报道了吡咯并[1,2- a ]喹喔啉与 TBAI 或 I 2的 C3-H 直接碘化反应;获得了一系列具有优异区域选择性和广泛底物范围的新型3-碘吡咯并[1,2- a ]喹喔啉衍生物。机理研究表明,催化量的对甲苯磺酸显着促进了反应的选择性和转化率。值得注意的是,该反应可以以克级进行,并且碘化产物可以通过钯催化的偶联反应进一步转化为具有潜在生物活性的吡咯并[1,2- a ]喹喔啉衍生物。
在醛基或酯基存在的情况下,硝基的化学选择性还原与另一种合成转化相结合,从而方便地合成重要的杂环,是当前研究的主题。N -(2-硝基苯基)吡咯-2-甲醛的化学选择性还原环化仅伴随工业试剂连二亚硫酸钠 (Na 2 S 2 O 4 ) 产生不同取代的吡咯稠合N -杂环已首次开发。原位生成的氨基通过化学选择性还原硝基与醛基缩合形成喹喔啉,或与酯基反应形成喹喔啉酮。该协议具有在室温下进行的高效单锅串联还原环化、非常短的反应时间(1 小时)、无水后处理、结晶纯化、分离产率通常 >90%、可观的官能团耐受性和广泛的底物范围。克级合成进一步证明了所开发协议的可扩展性。
Terminal methyl as a one-carbon synthon: synthesis of quinoxaline derivatives<i>via</i>radical-type transformation
作者:Xinfeng Wang、Huanhuan Liu、Caixia Xie、Feiyu Zhou、Chen Ma
DOI:10.1039/c9nj04910j
日期:——
pyrrolo[1,2-a]quinoxaline derivatives has been developed. Ferric chloride served as a promoter and as a Lewis acid in the reaction. Solvents provided the corresponding carbon sources simultaneously. The majority of solvents with terminal methyl groups, including ethers, amines and dimethyl sulfoxide, were reactive in the synthesis of quinoxaline derivatives at a certain yield via C–H(sp3) amination/C–O
已经开发了铁促进的吡咯并[1,2- a ]喹喔啉衍生物的构建方法。氯化铁在反应中用作促进剂和路易斯酸。溶剂同时提供了相应的碳源。大多数带有末端甲基的溶剂,包括醚,胺和二甲基亚砜,在通过C–H(sp 3)胺化/ C–O或C–N(C–S )分裂。该方法适用于多种吡咯并[1,2- a ]喹喔啉和吲哚并[1,2- a ]喹唑啉底物。
Transition‐metal‐free
<i>N</i>
‐arylation: A general approach to aza‐fused poly‐heteroaromatics
new and efficient method for the synthesis of various aza‐fused poly‐hetero aromatics has been described. This protocol includes an intermolecular condensation followed by metal‐free base‐promoted intramolecular C―Ncoupling reaction. The advantage of this one‐pot transformation lies in the use of simple cyclic amidines‐like compounds without prefunctionalization of the starting heterocycles.
Dimethyl Sulfoxide Involved One-Pot Synthesis of Quinoxaline Derivatives
作者:Caixia Xie、Zeyuan Zhang、Danyang Li、Jian Gong、Xushuang Han、Xuan Liu、Chen Ma
DOI:10.1021/acs.joc.6b02977
日期:2017.4.7
An efficient, green, and novel method for the synthesis of N-heterocycle-fused quinoxalines is reported herein. Dimethyl sulfoxide was used as both a reactant and a solvent in this reaction. A wide range of products in moderate to excellent yields were obtained, including pyrrolo[1,2-a]quinoxalines, indolo[1,2-a]quinoxalines, 1H-pyrrolo[3,2-c]quinolines, and benzo[4,5]imidazo[1,2-c]quinazolines.
本文报道了合成N-杂环融合的喹喔啉的有效,绿色和新颖的方法。在该反应中,二甲基亚砜既用作反应物又用作溶剂。获得了各种中等至优异收率的产品,包括吡咯并[1,2- a ]喹喔啉,吲哚并[1,2- a ]喹喔啉,1 H-吡咯并[3,2- c ]喹啉和苯并[ 4,5]咪唑并[1,2- c ]喹唑啉。
Cu-catalyzed direct C1−H difluoromethylation of pyrrolo[1,2-a]quinoxalines
作者:Yang Li、Zhen Yang、Yali Liu、Yan Liu、Yanlong Gu、Ping Liu
DOI:10.1016/j.mcat.2021.111747
日期:2021.7
An efficient Cu-catalyzed direct C1−H difluoromethylation of pyrrolo[1,2-a]quinoxalines with BrCF2CO2Et or BrCF2CONEt2 has been reported, providing to a series of difluoromethylated pyrrolo[1,2-a]quinoxalines with generally good yields. This approach features good compatibility with substituents, broad substrate scope, and gram-scale synthesis. The further transformations of the products are also examined
已经报道了用 BrCF 2 CO 2 Et 或 BrCF 2 CONEt 2对吡咯并[1,2- a ]喹喔啉进行有效的铜催化直接 C1-H 二氟甲基化,提供了一系列二氟甲基化吡咯并[1,2- a ]喹喔啉产量普遍良好。该方法具有与取代基的良好相容性、广泛的底物范围和克级合成。还检查了产品的进一步转化。
KI/TBHP-promoted [3 + 2] cycloaddition of pyrrolo[1,2-<i>a</i>]quinoxalines and <i>N</i>-arylsulfonylhydrazones
作者:Zhen Yang、Jing He、Yueting Wei、Weiwei Li、Ping Liu
DOI:10.1039/d0ob00494d
日期:——
An efficient KI/TBHP-promoted [3 + 2] cycloaddition of pyrrolo[1,2-a]quinoxalines and N-tosylhydrazones is described. A series of diverse fused [1,2,4]triazolo[3,4-c]quinoxalines was obtained in moderate to good yields with wide functional group tolerance. Importantly, this reaction can be performed on a gram scale, even in a one-pot fashion. In addition, further transformations of the products were