This review papers aims to comprehensively address the various aspects of ionic liquids and supported ionic liquids, which constitute a significant branch within the expansive field of green catalyst. Specifically, it delves into the recent advancements made in this domain over the past three years for the synthesis of heterocyclic compounds. In the introduction section of this review, the discussion revolves around the structural diversity of ionic liquids with an acidic nature. Furthermore, the introduction presents a clear and definitive classification system for diverse types of acidic ionic liquids. In the last part of this review paper, a comprehensive literature review would be provided on the application of ionic liquids and supported ionic liquids for the synthesis of heterocyclic compounds. The primary objective of this review is to present a comprehensive perspective on the utilization of ionic liquid and supported ionic liquid in the synthesis of various heterocyclic compounds. Special attention is given to the pivotal role played by reusable supported ionic liquids in this process. پرونده مقاله