sulfated titania nanoparticles: an efficient catalyst for the synthesis of polyhydroquinoline derivatives through hantzsch multicomponent reaction

sulfated titania nanoparticles (so42-/tio2 nps) were synthesized using titanium tetraisopropoxide (ttip) by the sol-gel method. the structure and morphology of the prepared nanocatalyst was characterized using x-ray diffraction (xrd), scanning electron microscopy (sem) and brunauer–emmett–teller (bet) methods as well as fourier transform infrared (ft-ir) and energy dispersive x-ray (edx) spectroscopy. the obtained nanoparticles were used as an efficient, reusable and environmentally friendly catalyst for the synthesis of polyhydroquinoline (phq) derivatives via a one-pot multicomponent reaction of various aldehydes, ammonium acetate and 1,3-dicarbonyl compounds under reflux conditions. the desired hantzsch esters were obtained in good to excellent yields and short reaction times. the so42- /tio2 nps could be recycled at least three times without significant loss of their catalytic activity.