An initial study has been accomplished into the synthetic feasibility of the preparation of diarylcarbenium salt via the direct coupling of aryl (or heteroaryl) aldehydes and arenes (or heteroaryl analogues) in the presence of a strong organic Brønsted acid. A number of stabilized aryl or heteroaryl(3-indolyl)carbenium ions, never previously prepared in the solid state, have been isolated in excellent
Herein, we demonstrated Mn-catalyzed selective C-3 functionalization of indoles with alcohols. The developed catalyst can also furnish bis(indolyl)methanes from the same set of substrates under slightly modified reaction conditions. Mechanistic studies reveal that the C-3 functionalization of indoles is going via a borrowing hydrogen pathway. To highlight the practical utility, a diverse range of substrates
Visible light mediated Iron-Catalyzed synthesis of C-3 alkylated Indoles, bisindolylmethanes and flavanones using alcohols
作者:Mohd Waheed、Meshari A Alsharif、Mohammed Issa Alahmdi、Sayeed Mukhtar、Humaira Parveen
DOI:10.1016/j.tetlet.2023.154428
日期:2023.4
benign, mild approach for synthesis of C-3 alkylated indoles, bisindolylmethanes and flavanones using alcohols at room temperature under visible light has been developed. The reported reaction conditions were favorable for a wide range of alcohols afforded good to excellent yields of the respective products. Additionally, the reaction system was successfully extended to the synthesis of flavanones from
Oxygen Dependent Switchable Selectivity during Ruthenium Catalyzed Selective Synthesis of <i>C3</i>-Alkylated Indoles and Bis(indolyl)methanes
作者:Amit Kumar Guin、Subhasree Pal、Subhajit Chakraborty、Santana Chakraborty、Nanda D. Paul
DOI:10.1021/acs.joc.3c01191
日期:2023.12.15
redox-controlled oxygen-dependent switchable selectivity during ruthenium-catalyzed selective synthesis of C3-alkylated indoles and bis(indolyl)methanes (BIMs). A wide variety of C3-alkylated indoles and BIMs were prepared selectively in moderate to good isolated yields by coupling a wide variety of indoles and alcohols, catalyzed by a well-defined, air-stable, and easy-to-prepare Ru(II)-catalyst (1a)
在此,我们报道了在钌催化选择性合成C3烷基化吲哚和双(吲哚基)甲烷(BIM)过程中以配体为中心的氧化还原控制的氧依赖性可切换选择性。在结构明确、空气稳定且易于制备的 Ru(II) 催化下,通过偶联多种吲哚和醇,以中等至良好的分离收率选择性地制备多种C3烷基化吲哚和 BIM -带有氧化还原活性三齿钳( L 1a )的催化剂( 1a )。催化剂1a在氩气气氛下有效催化吲哚的C3烷基化,同时在氧气环境下专门产生BIM。一些含有 BIM 的药物分子也被有效合成。 1a对含有内部碳-碳双键的醇表现出优异的化学选择性。机理研究表明,配位偶氮芳香配体在催化过程中积极参与。在醇脱氢过程中,配体的偶氮部分储存从醇中除去的氢,随后将氢转移至亚烷基吲哚中间体,形成C3烷基化吲哚。而在氧气环境下,氢从配体支架转移到分子氧会产生H 2 O 2 ,不给亚烷基假吲哚中间体的氢化留下余地,而不是进行1,4-迈克尔型加成形成BIM。
Synthesis of Bench-Stable Diarylmethylium Tetrafluoroborates
作者:Margherita Barbero、Roberto Buscaino、Silvano Cadamuro、Stefano Dughera、Andrea Gualandi、Domenica Marabello、Pier Giorgio Cozzi
DOI:10.1021/acs.joc.5b00418
日期:2015.5.1
A representative number of bench-stable nonsymmetric diarylcarbenium tetrafluoroborates have been isolated via the direct coupling of aryl (or heteroaryl) aldehydes and N-heteroarenes and fully characterized. They have proven to be highly stable in the presence of both EDG and EWG substituents. An (E)-iminium vinylogous substructure has been shown as the common cation scaffold by X-ray analysis and by NOE determination.