HFIP-Empowered One-Pot Synthesis of C4-Aryl-Substituted Tetrahydroquinolines with Propargylic Chlorides and Anilines
Seung Hoon Lee1, Hyung Min Chi1,2
1Department of Chemistry, Pohang University of Science and Technology, Pohang 37673, South Korea.
Abstract:
Transition-metal-free, practical one-pot synthesis of C4-aryl-substituted tetrahydroquinolines from simple anilines and readily accessible propargylic chlorides has been developed. Activation of the C-Cl bond by 1,1,1,3,3,3-hexafluoroisopropanol turned out to be the key interaction, which allowed C-N bond formation under an acidic medium. Propargylated aniline is formed as an intermediate via propargylation, and subsequential cyclization and reduction gave 4-arylated tetrahydroquinolines. To demonstrate the synthetic utility, total syntheses of aflaquinolone F and I have been accomplished.
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