Hydrogen Bond Assisted Three-Component Tandem Reactions to Access <i>N</i>-Alkyl-4-Quinolones

Abstract

Hydrogen-bonding catalytic reactions have gained great interest. Herein, a hydrogen-bond-assisted three-component tandem reaction for the efficient synthesis of N-alkyl-4-quinolones is described. This novel strategy features the first proof of polyphosphate ester (PPE) as a dual hydrogen-bonding catalyst and the use of readily available starting materials for the preparation of N-alkyl-4-quinolones. The method provides a diversity of N-alkyl-4-quinolones in moderate to good yields. The compound 4h demonstrated good neuroprotective activity against N-methyl-ᴅ-aspartate (NMDA)-induced excitotoxicity in PC12 cells.

Keywords

• hydrogen bond
• polyphosphoric acid
• polyphosphate ester
• <i>N</i>-alkyl-4-quinolones
• neuroprotective activity