Cascade One-Pot Synthesis of Orange-Red-Fluorescent Polycyclic Cinnolino[2,3-f]phenanthridin-9-ium Salts by Palladium(II)-Catalyzed C-H Bond Activation of 2-Azobiaryl Compounds and Alkenes

Jayachandran Jayakumar; Guganchandar Vedarethinam; Huan-Chang Hsiao; Shang-You Sun; Shih-Ching Chuang

doi:10.1002/anie.201910959

Cascade One-Pot Synthesis of Orange-Red-Fluorescent Polycyclic Cinnolino[2,3-f]phenanthridin-9-ium Salts by Palladium(II)-Catalyzed C-H Bond Activation of 2-Azobiaryl Compounds and Alkenes

Angew Chem Int Ed Engl. 2020 Jan 7;59(2):689-694. doi: 10.1002/anie.201910959. Epub 2019 Nov 19.

Authors

Jayachandran Jayakumar¹, Guganchandar Vedarethinam¹, Huan-Chang Hsiao¹, Shang-You Sun¹, Shih-Ching Chuang¹

Affiliation

¹ Department of Applied Chemistry, National Chiao Tung University, Hsinchu, 30010, Taiwan.

PMID: 31617286
DOI: 10.1002/anie.201910959

Abstract

Quaternary ammonium salts were synthesized in moderate to good yields through double oxidative C-H bond activation on azobenzenes. The mechanism of the highly regioselective reaction of 2-azobiaryls with alkenes to give orange-red-fluorescent cinnolino[2,3-f]phenanthridin-9-ium salts and 15H-cinnolino[2,3-f]phenanthridin-9-ium-10-ide is proposed to involve ortho C-H olefination of the 2-azobiaryl compound with the alkene, intramolecular aza-Michael addition, concerted metalation-deprotonation (CMD), reductive elimination, and oxidation.

Keywords: C−H activation; alkenes; azobenzenes; fluorescence; palladium catalysis.

Abstract

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