AbstractSyntheses of (partially) aromatic nitrogen heterocycles increasingly rely on transition‐metal catalyzed C−C‐ and C−N‐cross‐coupling reactions. Here we describe a different approach to the synthesis of indolines by a domino C(sp3)−H activation, 1,2‐addition, and defluorinative SNAr‐cyclization sequence to provide the target 1,2‐diarylindolines (1,2‐diaryl‐2,3‐dihydroindoles) from ortho‐fluorinated methyl‐arenes and N‐aryl imines (benzylidene anilines) in a cyclocondensation that is mediated by potassium hexamethyldisilazide (KHMDS) as base exclusively. This transition‐metal‐free process via C−H and C−F bond activation provides a one‐step entry into a wide array of indoline scaffolds (43 examples, up to 96 % yield). This privileged substructure is common in natural products and pharmaceuticals alike, and cannot be accessed by traditional condensation reactions.
Solvent-Switched Benzylic Methylene Functionalization: Addition, Ring-Opening, Cyclization, and Unexpected Cleavage of C–O and C–C Bonds
作者:Deng Yuan Li、Xue Song Shang、Guo Rong Chen、Pei Nian Liu
DOI:10.1021/ol401470y
日期:2013.8.2
been achieved using imines as reagents and potassium tert-butoxide as the catalyst. Depending on the solvent used, the reaction proceeds by two pathways. In THF, an addition/elimination reaction of exo-cyclic enol ethers with imines provides dihydroisobenzofuranderivatives in good yield. In DMSO, an addition/ring-opening/cyclization cascade reaction occurs with unexpected cleavage of C–O and C–C bonds
Transition Metal-Free Cascade Reactions of Alkynols to Afford Isoquinolin-1(2<i>H</i>)-one and Dihydroisobenzofuran Derivatives
作者:Deng Yuan Li、Ke Ji Shi、Xiao Feng Mao、Guo Rong Chen、Pei Nian Liu
DOI:10.1021/jo5006312
日期:2014.5.16
Transition metal-free cascade reactions of alkynols with imines have been achieved using potassium tert-butoxide as catalyst. Switching the reaction solvent gives two kinds of products in good yield: isoquinolin-1(2H)-one derivatives and dihydroisobenzofuran derivatives. This approach was used to generate the natural product 8-oxypseudopalmatine in a two-step procedure from commercially available starting materials. Additionally, multicomponent reactions of alkynols, aldehydes, and amines were also successfully achieved to afford isoquinolin-1(2H)-one derivatives.
Suschitzky,H. et al., Journal of the Chemical Society. Perkin transactions I, 1977, p. 47 - 52
作者:Suschitzky,H. et al.
DOI:——
日期:——
10.1002/chem.202401034
作者:Weindl, Christian、Hintermann, Lukas
DOI:10.1002/chem.202401034
日期:——
AbstractSyntheses of (partially) aromatic nitrogen heterocycles increasingly rely on transition‐metal catalyzed C−C‐ and C−N‐cross‐coupling reactions. Here we describe a different approach to the synthesis of indolines by a domino C(sp3)−H activation, 1,2‐addition, and defluorinative SNAr‐cyclization sequence to provide the target 1,2‐diarylindolines (1,2‐diaryl‐2,3‐dihydroindoles) from ortho‐fluorinated methyl‐arenes and N‐aryl imines (benzylidene anilines) in a cyclocondensation that is mediated by potassium hexamethyldisilazide (KHMDS) as base exclusively. This transition‐metal‐free process via C−H and C−F bond activation provides a one‐step entry into a wide array of indoline scaffolds (43 examples, up to 96 % yield). This privileged substructure is common in natural products and pharmaceuticals alike, and cannot be accessed by traditional condensation reactions.