Iodine-Catalyzed Aza-Diels–Alder Reactions of Aliphatic N-Arylaldimines

Abstract

Iodine-catalyzed aza-Diels–Alder (Povarov) reaction of 3,4-dihydro-2H-pyran with in situ generated N-arylimines containing enolizable protons is described. This has given an easy way to introduce C-2 aliphatic substitution in tetrahydroquinolines.

Keywords:

• 3,4-Dihydro-2H-pyrane
• imino Diels–Alder reaction
• iodine
• pyranoquinolines

ACKNOWLEDGMENTS

One of the authors, N. P. S. R., thanks Dr. Goutam Das, president, Syngene International Ltd., for constant motivation and allocation of resources for this work.

Notes

^a All the reactions were carried out with 30 mol% iodine in acetonitrile at ambient temperature.

^b Isolated yields after flash-column chromatography.

^c Isomer ratios were calculated based on ¹H NMR spectra of the crude products.

^a Combined isolated yields.