Use of iodine doped polyaniline salt in the stereoselective synthesis of 2-methyl-4-substituted-1,2,3,4-tetrahydroquinoline derivatives

Polyaniline–iodine salt is proved as a simple, efficient, versatile, recyclable and eco-friendly polymer based solid acid catalyst in the reaction between aromatic amines and N-vinyl pyrrolidone/N-vinyl caprolactam under solvent free condition. Polyaniline salts such as polyaniline-sulfate, polyaniline-hydrochloride and polyaniline-perchlorate are also catalyzing this reaction smoothly.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► PANI serves as recyclable catalyst to synthesize cis tetrahydroquinolines. ► PANI-I2 catalyst is more stable, recyclable, less hygroscopic and corrosive than I2. ► The developed process conforms to the principles of ‘green’ chemistry.