An efficient palladium-catalyzed nucleophilic substitution/C–H activation/aromatization cascade reaction between readily available 2-halo-N-Ms-arylamines (Ms = methanesulfonyl) and benzyl halides/sulfonates has been described. A wide variety of phenanthridines were synthesized in a one-pot fashion in moderate to high yields (37–86 %). Notably, this method provides a straightforward, facile approach
Expeditious synthesis of phenanthridines through a Pd/MnO<sub>2</sub>-mediated C–H arylation/oxidative annulation cascade from aldehydes, aryl iodides and amino acids
作者:Jian Fan、Li Li、Jitan Zhang、Meihua Xie
DOI:10.1039/d0cc00300j
日期:——
The expeditious construction of phenanthridine scaffolds via a Pd/MnO2-mediated C-H arylation/oxidative annulationcascade involving aldehydes, aryl iodides and amino acids is disclosed. This reaction proceeds smoothly involving the formation of multiple chemical bonds with the tolerance of a wide range of functional groups. The control experiments suggest a radical mechanism for C-N bond formation
A radical addition/cyclization of diverse ethers to 2-isocyanobiaryls under mildly basic aqueous conditions
作者:Cintia Anton-Torrecillas、Diego Felipe-Blanco、Jose C. Gonzalez-Gomez
DOI:10.1039/c6ob02103d
日期:——
Mildly basic aqueous conditions facilitated the tert-butyl peroxybenzoate (TBPB) mediated dehydrogenative addition of a range of ethers, including acetals, to diverse substituted 2-isocyanobiaryls. Mechanistic studies suggest that this radical cascade is an example of base promoted homolytic aromatic substitution (BHAS).
Synthesis of Phenanthridines through Iodine-Supported Intramolecular C–H Amination and Oxidation under Visible Light
作者:Yan Gao、Yi Jing、Lixin Li、Jie Zhang、Xuenian Chen、Yan-Na Ma
DOI:10.1021/acs.joc.0c01390
日期:2020.10.2
Herein, we report a metal-free and step-economic synthesis of phenanthridines from 2-biarylmethanamines under mild conditions. The reaction involves iodine-supported intramolecular C–H amination and oxidation of 5,6-dihydrophenanthridine under air and benign visible light. The mechanism study reveals that visible light plays a key role in both these steps.
annulation between 2-aminobiphenyls and activated olefins is disclosed for succinct synthesis of valuable phenanthridine scaffolds. The protocol avails a common organic functional group, free amine, as a directing group and represents a unique combination of C–Hactivation/annulation/C–C bond cleavage cascade that bodes well in the production of bioactive alkaloids including trisphaeridine and bicolorine