A novel and green synthesis of indolone-N-amino acid derivatives via the Passerini three-component reactions in water

A green Passerini three-component reaction of 2-(4-oxo-4,5,6,7-tetrahydro-1H-indol-1-yl)acetic acid with alkyl or aryl isocyanides and aldehydes was reported under aqueous conditions at 35 °C for 1 h, and 21 indolone-N-amino acid derivatives were prepared in high yields of 42%–99%. Their structures were characterized by IR, ESI–MS, NMR and elemental analysis, and the possible mechanisms have been also proposed. The highly efficient and eco-friendly method provides a facile access to a library of indolone-N-amino acid derivatives for future research on bioactivity screening.

Graphical abstractA series of 21 indolone-N-amino acid derivatives have been synthesized through an aqueous Passerini three-component reaction in 42%–99% yields. The highly efficient and eco-friendly method provides a facile access to a library of indolone-N-amino acid derivatives for future research on bioactivity screening.Figure optionsDownload full-size imageDownload as PowerPoint slide