N-Acyloxyphthalimides as Nitrogen Radical Precursors in the Visible Light Photocatalyzed Room Temperature C–H Amination of Arenes and Heteroarenes
نویسندگان
چکیده
This paper reports a room temperature visible light photocatalyzed method for the C-H amination of arenes and heteroarenes. A key enabling advance in this work is the design of N-acyloxyphthalimides as precursors to nitrogen-based radical intermediates for these transformations. A broad substrate scope is presented, including the selective meta-amination of pyridine derivatives. A radical aromatic substitution mechanism is proposed.
منابع مشابه
Teaching Old Compounds New Tricks: DDQ‐Photocatalyzed C−H Amination of Arenes with Carbamates, Urea, and N‐Heterocycles
The C-H amination of benzene derivatives was achieved using DDQ as photocatalyst and BocNH2 as the amine source under aerobic conditions and visible light irradiation. Electron-deficient and electron-rich benzenes react as substrates with moderate to good product yields. The amine scope of the reaction comprises Boc-amine, carbamates, pyrazoles, sulfonimides and urea. Preliminary mechanistic in...
متن کاملRoom Temperature Synthesis of N-doped Urchin-like Rutile TiO2 Nanostructure With Enhanced Photocatalytic Activity Under Sunlight
We report the synthesis of nitrogen-doped urchin-like rutile TiO2 nanostructure at room temperature without further heat treatment. The process was operated through hydrolysis of Ti(OC4H9)4 employing the direct amination of the product. The samples characterized by x-ray diffraction (XRD), scanning electron microscopy (SEM), Transmission electron microscopy (TEM), Raman spectroscopy and Brunaue...
متن کاملDirect alkylation of heteroarenes with unactivated bromoalkanes using photoredox gold catalysis
Although visible light photoredox catalysis has emerged as a powerful tool for the construction of C–C bonds, common catalysts and/or their photoexcited states suffer from low redox potentials, limiting their applicability to alkyl radical generation from substrates with activated carbon–halogen bonds. Radicals derived from these activated compounds, being highly electrophilic or stabilized, do...
متن کاملPalladium-Catalyzed Direct Arylation of 5-Halouracils and 5-Halouracil Nucleosides with Arenes and Heteroarenes Promoted by TBAF
The 1-N-benzyl-5-iodo(or bromo)uracil undergoes Pd-catalyzed [Pd2(dba)3] direct arylation with benzene and other simple arenes in the presence of TBAF in DMF without the necessity of adding any ligands or additives to give 5-arylated uracil analogues. The TBAF-promoted coupling also occurs efficiently with electron rich heteroarenes at 100 °C (1 h) even with only small excess of heteroarenes. T...
متن کاملA new face of phenalenyl-based radicals in the transition metal-free C–H arylation of heteroarenes at room temperature: trapping the radical initiator via C–C σ-bond formation† †Electronic supplementary information (ESI) available. CCDC 1520738. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c7sc02661g Click here for additional data file. Click here for additional data file.
The radical-mediated transition metal-free approach for the direct C–H bond functionalization of arenes is considered as a cost effective alternative to transition metal-based catalysis. An organic ligand-based radical plays a key role by generating an aryl radical which undergoes a subsequent functionalization process. The design principle of the present study takes advantage of a relatively s...
متن کامل