Ultrasound-Assisted, ZnCr2O4 Nanocatalyzed Synthesis of Substituted Tetrahydroquinolines via Povarov Reaction

Eco-friendly, reusable ZnCr2O4 Nano catalyzed tetrahydroquinoline derivatives are prepared via Povarov reaction route from aromatic aldehydes, α-amino naphthalene, and 2,3-dihydrofuran under reflux/ultrasonic irradiation methods. This several affords several benefits like good to excellent yields, a higher percentage of atom economy. Substituted tetrahydroquinolines have been shown great biological potential.

(2S*,4S*)-4-[(E)-(2,2-Dimethylhydrazono)methyl]-6-methoxy-4-methyl-2-[(E)-styryl]-1,2,3,4-tetrahydroquinoline

The Povarov reaction of p-anisidine, cinnamaldehyde and methacrolein dimethylhydrazone afforded a 1,2,3,4-tetrahydroquinoline derivative bearing 2-styryl, 4-methyl and 4-dimethylhydrazono substituents in a fully diastereoselective fashion. This is the first example of the combination of a type I aza-vinylogous Povarov reaction and a type II vinylogous Povarov reaction in the same process.