The ball-milling process of ABB' Povarov reaction through mechano-chemical activation with phosphomolybdic acid (PMA) as heteropolyacid (HPA) catalyst, was first time explored. The developed high speed vibratory ball milling (HSVBM) green method offers simple and efficient diastereoselective synthesis of cis-2,4-disubstituted tetrahydroquinolines in good to excellent yields (56-76%).
Keywords:
mechano-chemical milling; ABB' Povarov type reaction; phosphomolybdic acid catalyst; solvent-free Povarov reaction