Propylsulfonic Acid-Anchored Isocyanurate-Based Periodic Mesoporous Organosilica (PMO-ICS-PrSO3H): A Highly Efficient and Recoverable Nanoporous Catalyst for the One-Pot Synthesis of Substituted Polyhydroquinolines

摘要

Propylsulfonic acid-anchored isocyanurate bridging periodic mesoporous organosilica (PMO-ICS-PrSO3H) was shown to be a highly active and efficient recyclable catalyst for the four-component synthesis of polyhydroquinoline derivatives from dimedone, different aldehydes, ethyl acetoacetate and ammonium acetate under mild reaction conditions in short reaction times and good to excellent yields in EtOH. Moreover, the catalyst was also recovered and reused at least four times without significant decrease in its activity. The PMO-ICS-PrSO3H catalyst was characterized by FTIR spectroscopy, TGA, nitrogen adsorption-desorption isotherms as well as FESEM. Compared to the classical methodologies, this method illustrated significant advantages including low loading of the catalyst, avoiding the use of toxic transition metals or reactive reagents for modification of the catalytic activity, short reaction times, high to excellent yields, easy separation and purification of the products, and reusability of the catalyst.