Nickel containing ionic liquid based ordered nanoporous organosilica: a powerful and recoverable catalyst for synthesis of polyhydroquinolines

Abstract

A novel nickel containing alkyl-imidazolium ionic liquid based ordered mesoporous organosilica (Ni@IL-OMO) is prepared, characterized and applied as an efficient nanocatalyst in the one-pot synthesis of polyhydroquinolines through the Hantzsch reaction. The Ni@IL-OMO was prepared via immobilization of nickel chloride on IL-OMO at room temperature. This was characterized using transmission electron microscopy (TEM), FTIR-spectroscopy, nitrogen adsorption–desorption analysis, scanning electron microscopy (SEM) and energy-dispersive X-ray (EDX) spectroscopy. The polyhydroquinolines were obtained in high to excellent yield and selectivity in the presence of a low loading of Ni@IL-OMO with short reaction times. This catalyst was recovered and reused several times while keeping its efficiency under the applied conditions. The recovered catalyst was analyzed by TEM to study its structural stability during reaction process.