The First Domino Reduction/Imine Formation/Intramolecular Aza-Diels–Alder Reaction for the Diastereoselective Preparation of Tetrahydrochromano[4,3-b]quinolines
- Publication Type
- Journal contribution (peer reviewed)
- Authors
- Imrich, H.-G. ; Conrad, J.; Beifuss, U.
- Year of publication
- 2016
- Published in
- Eur. J. Org. Chem.
- DOI
- 10.1002/ejoc.201600976
- Page (from - to)
- 5706-5715
The first domino reduction/imine formation/intramolecular aza-Diels–Alder reaction is reported. Tetrahydrochromano[4,3-b]quinolines are formed with high exo-E-anti selectivity and yields up to 87 % when a nitrobenzene and a 2-(cinnamyloxy)benzaldehyde are reacted in aqueous citric acid by using iron as a reductant and montmorillonite K10 as a catalyst. The domino process starts with the in situ reduction of the nitrobenzene to the corresponding aniline, which is followed by imine formation and terminated by an intramolecular aza-Diels–Alder reaction.