Advances in Pyrazoles Rings’ Syntheses by Heterogeneous Catalysts, Ionic Liquids, and Multicomponent Reactions - A Review

Abstract: Nitrogen heterocycles represent one of the most important units in modern organic chemistry besides their wide existence broadly in natural products, pharmaceuticals, and functional materials. Among these heterocycles, pyrazole, the molecule of the present work, received much attention in organic synthesis because it delivers significant therapeutic and biological values as it was found to be the core unit of many drugs, agrochemicals, and related candidates. Due to this fact, the development of practical methodologies for the preparation of pyrazoles has attracted the long-standing interest of synthetic chemists. Synthetic heterocyclic chemistry using green methods has captivated many researchers in the recent past due to its easy operation and environmentally friendliness. In this review, we summarized systematic approaches for the synthesis of pyrazole derivatives via heterogeneous catalysis, ionic liquid catalysis, and multicomponent reactions.